Ga-DOTA-FAPI-04 PET/MR in the evaluation of gastric carcinomas: comparison with F-FDG PET/CT.
Qin Chunxia,Shao Fuqiang,Gai Yongkang,Liu Qingyao,Ruan Weiwei,Liu Fang,Hu Fan,Lan Xiaoli
Journal of nuclear medicine : official publication, Society of Nuclear Medicine
We sought to evaluate the performance of Ga-DOTA-FAPI-04 (Ga-FAPI) PET/MR for the diagnosis of primary tumor and metastatic lesions in patients with gastric carcinomas and to compare the results with those of F-FDG PET/CT. Twenty patients with histologically proven gastric carcinomas were recruited, and each patient underwent both F-FDG PET/CT and Ga-FAPI PET/MR. A visual scoring system was established to compare the detectability of primary tumors and metastases in different organs/regions (the peritoneum, abdominal lymph nodes, supradiaphragmatic lymph nodes, liver, ovary, bone, and other tissues). The original maximum standardized uptake value (SUV) and normalized SUV (calculated by dividing a lesion's original SUV with the mean SUV of the descending aorta) of selected lesions on both F-FDG PET/CT and Ga-FAPI PET/MR were measured. Original/normalized SUV-FAPI and SUV-FDG were compared for patient-based (including a single lesion with the highest activity uptake in each organ/region) and lesion-based (including all lesions [≤ 5] or the 5 lesions with highest activity [> 5]) analyses, respectively. The 20 recruited patients (median age: 56.0 y; range: 29-70 y) included 9 men and 11 women, 14 patients for initial staging and 6 for recurrence detection. Ga-FAPI PET was superior to F-FDG PET for primary tumor detection (100.00% [14/14] vs 71.43% [10/14], = 0.034), and the former had higher tracer uptake levels ( < 0.05). Ga-FAPI PET was superior to F-FDG PET in both patient-based and lesion-based evaluation except for the metastatic lesions in supradiaphragmatic lymph nodes and ovaries. Additionally, multiple sequences of MR images were beneficial for the interpretation of hepatic metastases in 3 patients, uterine and rectal metastases in 1 patient, ovarian lesions in 7 patients, and osseous metastases in 2 patients. Ga-FAPI PET/MR outperformed F-FDG PET/CT in visualizing the primary and most metastatic lesions of gastric cancer, and might be a promising method with the potential of replacing F-FDG PET/CT.
The usefulness of b value threshold map in the evaluation of rectal adenocarcinoma.
Shen Fu,Chen Luguang,Li Zhihui,Lu Haidi,Chen Yukun,Wang Zhen,Fu Caixia,Grimm Robert,Lu Jianping
Abdominal radiology (New York)
PURPOSE:To investigate the usefulness of b value threshold (b) map in the evaluation of rectal adenocarcinoma by comparing it with diffusion-weighted images and ADC maps regarding lesion detection and the prediction of pathological features. MATERIALS AND METHODS:Thirty-five patients with rectal tumors were enrolled and underwent axial DWI using a 3-Tesla MRI system. Contrast-to-noise ratio (CNR) between the lesions and normal tissues were assessed on the diffusion-weighted images and b maps. Reproducibility for ADC and b values were assessed. Significant differences between different groups for pathological prognostic factors were evaluated. Diagnostic performance of ADC and b values for those factors were assessed. RESULTS:Reproducibility was excellent for the ADC and b values (ICC 0.985 and 0.992; CV 3.8% and 4.0%) measurements. The CNR between lesions and normal tissues on b maps was significantly higher than that on diffusion-weighted images (9.91 ± 5.35 vs. 7.68 ± 3.08, p = 0.012). There were significant differences in the ADC and b values between different pathologic differentiation degrees and T stages; significant difference was observed in the b values between the different N stage groups (all p values < 0.050). No significant differences were observed between the ROC curves of ADC and the b values of rectal lesions for pathologic differentiation and T stage. b maps showed good diagnostic performance for N stage. CONCLUSION:Both ADC and b values can differentiate between degrees of pathologic differentiation and T1-2 versus T3-4. Potential added advantages however of the b map include a higher CNR compared with DWI images, thereby improving lesion visualization detection, and better diagnostic performance for end staging than ADC. Thus, the b map may compliment DWI and ADC to evaluate pathologic features of rectal primary tumors and metastatic lymph nodes.
Preoperative locoregional staging of rectal carcinoma: comparison of MR, TRUS and Multislice CT. Personal experience.
Panzironi Giuseppe,De Vargas Macciucca Marina,Manganaro Lucia,Ballesio Laura,Ricci Francesca,Casale Alessandra,Campagnano Deborah
La Radiologia medica
PURPOSE:The aim of this study was to measure the sensitivity and clinical indications of Magnetic Resonance (MR) as compared to Transrectal Ultrasonography (TRUS) and spiral Computed Tomography (CT) in the preoperative staging and evaluation of rectal carcinoma. MATERIALS AND METHODS:Twenty patients with histologically proven rectal carcinoma were examined with phased-array coil MRI. We used T1 and T2, spin-echo, turbo-spin-echo, flash2D sequences with and without fat suppression; FOV 180-280; 4-6 mm slice thickness; i.v. Gadolinium. The MR images were compared with TRUS, spiral CT and with the final histological diagnosis. RESULTS:MR showed a 92.3% sensitivity for rectal wall infiltration vs. 100% of TRUS and 75% of CT. The sensitivity for lymph node metastases was 76.4% vs. 72.2% for TRUS and 88% for CT. CONCLUSIONS:Locoregional staging of rectal cancer by MRI shows a high sensitivity and is also feasible in stenosing or proximal rectal lesions. TRUS, despite its limitations, is still the most sensitive method for the evaluation of wall infiltration. CT was less sensitive than the other two METHODS:The sensitivity of MR and CT for lymph node metastases is comparable, but the former is more specific.
Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society.
Attenberger Ulrike Irmgard,Clasen Stephan,Ghadimi Michael,Grosse Ulrich,Antoch Gerald,Schreyer Andreas G,Wessling Johannes,Hausmann Daniel,Piso Pompiliu,Plodeck Verena,Stintzing Sebastian,Rödel Claus Michael,Hofheinz Ralf Dieter
RoFo : Fortschritte auf dem Gebiete der Rontgenstrahlen und der Nuklearmedizin
Due to its excellent intrinsic soft tissue contrast, magnetic resonance imaging allows excellent visualization and anatomical separation of therapy-relevant risk structures such as the mesorectal fascia, local lymph nodes, and vascular structures in patients with rectal carcinoma. This makes magnetic resonance imaging (MRI) a valuable evaluation method for further therapeutic stratification. In particular, MRI is indispensable for the decision to refrain from neoadjuvant therapy and to choose a primary surgical approach. In addition to the oncologically generally relevant T-, N-, and M-criteria, two further parameters are included: the extramural vascular infiltration and the circumferential resection margin. Due to the significant impact of MRI on further therapeutic decision-making, standardized MR image quality is considered essential. KEY POINTS:: · Magnetic resonance imaging is a valuable evaluation method for further therapeutic stratification.. · Critical anatomic landmarks for evaluation are circumferential resection margins.. CITATION FORMAT: · Attenberger UI, Clasen S, Ghadimi M et al. Importance and Qualitative Requirements of Magnetic Resonance Imaging for Therapy Planning in Rectal Cancer - Interdisciplinary Recommendations of AIO, ARO, ACO and the German Radiological Society. Fortschr Röntgenstr 2021; 193: 513 - 520.
Fusion of high b-value diffusion-weighted and T2-weighted MR images improves identification of lymph nodes in the pelvis.
Mir N,Sohaib S A,Collins D,Koh D M
Journal of medical imaging and radiation oncology
Accurate identification of lymph nodes facilitates nodal assessment by size, morphological or MR lymphographic criteria. We compared the MR detection of lymph nodes in patients with pelvic cancers using T2-weighted imaging, and fusion of diffusion-weighted imaging (DWI) and T2-weighted imaging. Twenty patients with pelvic tumours underwent 5-mm axial T2-weighted and DWI (b-values 0-750 s/mm(2)) on a 1.5T system. Fusion images of b = 750 s/mm(2) diffusion-weighted MR and T2-weighted images were created. Two radiologists evaluated in consensus the T2-weighted images and fusion images independently. For each image set, the location and diameter of pelvic nodes were recorded, and nodal visibility was scored using a 4-point scale (0-3). Nodal visualisation was compared using Relative to an Identified Distribution (RIDIT) analysis. The mean RIDIT score describes the probability that a randomly selected node will be better visualised relative to the other image set. One hundred fourteen pelvic nodes (mean 5.9 mm; 2-10 mm) were identified on T2-weighted images and 161 nodes (mean 4.3 mm; 2-10 mm) on fusion images. Using fusion images, 47 additional nodes were detected compared with T2-weighted images alone (eight external iliac, 24 inguinal, 12 obturator, two peri-rectal, one presacral). Nodes detected only on fusion images were 2-9 mm (mean 3.7 mm). Nodal visualisation was better using fusion images compared with T2-weighted images (mean RIDIT score 0.689 vs 0.302). Fusion of diffusion-weighted MR with T2-weighted images improves identification of pelvic lymph nodes compared with T2-weighted images alone. The improved nodal identification may aid treatment planning and further nodal characterisation.
Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and MR imaging--a meta-analysis.
Bipat Shandra,Glas Afina S,Slors Frederik J M,Zwinderman Aeilko H,Bossuyt Patrick M M,Stoker Jaap
PURPOSE:To perform a meta-analysis to compare endoluminal ultrasonography (US), computed tomography (CT), and magnetic resonance (MR) imaging in rectal cancer staging. MATERIALS AND METHODS:Relevant articles published between 1985 and 2002 were included if more than 20 patients were studied, histopathologic findings were the reference standard, and data were presented for 2 x 2 tables; articles were excluded if data were reported elsewhere in more detail. Two reviewers independently extracted data on study characteristics and results. Bivariate random-effects approach was used to obtain summary estimates of sensitivity and specificity for invasion of muscularis propria, perirectal tissue, and adjacent organs and for lymph node involvement. Summary receiver operating characteristic (ROC) curves were fitted for perirectal tissue invasion and lymph node involvement. RESULTS:Ninety articles fulfilled all inclusion criteria. For muscularis propria invasion, US and MR imaging had similar sensitivities; specificity of US (86% [95% confidence interval [CI]: 80, 90]) was significantly higher than that of MR imaging (69% [95% CI: 52, 82]) (P =.02). For perirectal tissue invasion, sensitivity of US (90% [95% CI: 88, 92]) was significantly higher than that of CT (79% [95% CI: 74, 84]) (P <.001) and MR imaging (82% [95% CI: 74, 87]) (P =.003); specificities were comparable. For adjacent organ invasion and lymph node involvement, estimates for US, CT, and MR imaging were comparable. Summary ROC curve for US of perirectal tissue invasion showed better diagnostic accuracy than that of CT and MR imaging. Summary ROC curves for lymph node involvement showed no differences in accuracy. CONCLUSION:For local invasion, endoluminal US was most accurate and can be helpful in screening patients for available therapeutic strategies.
Magnetic resonance imaging of rectal cancer: staging and restaging evaluation.
Moreno Courtney C,Sullivan Patrick S,Kalb Bobby T,Tipton Russell G,Hanley Krisztina Z,Kitajima Hiroumi D,Dixon W Thomas,Votaw John R,Oshinski John N,Mittal Pardeep K
Magnetic resonance imaging is used to non-invasively stage and restage rectal adenocarcinomas. Accurate staging is important as the depth of tumor extension and the presence or absence of lymph node metastases determines if an individual will undergo preoperative neoadjuvant chemoradiation. Accurate description of tumor location is important for presurgical planning. The relationship of the tumor to the anal sphincter in addition to the depth of local invasion determines the surgical approach used for resection. High-resolution T2-weighted imaging is the primary sequence used for initial staging. The addition of diffusion-weighted imaging improves accuracy in the assessment of treatment response on restaging scans. Approximately 10%-30% of individuals will experience a complete pathologic response following chemoradiation with no residual viable tumor found in the resected specimen at histopathologic assessment. In some centers, individuals with no residual tumor visible on restaging MR who are thought to be at high operative risk are monitored with serial imaging and a "watch and wait" approach in lieu of resection. Normal rectal anatomy, MR technique utilized for staging and restaging scans, and TMN staging are reviewed. An overview of surgical techniques used for resection including newer, minimally invasive endoluminal techniques is included.
Diagnostic accuracy of nodal enhancement pattern of rectal cancer at MRI enhanced with ultrasmall superparamagnetic iron oxide: findings in pathologically matched mesorectal lymph nodes.
Koh Dow-Mu,George Christopher,Temple Louis,Collins David J,Toomey Paul,Raja Ashraf,Bett Nicholas,Farhat Sami,Husband Janet E,Brown Gina
AJR. American journal of roentgenology
OBJECTIVE:The purpose of this study was to evaluate the diagnostic accuracy of the pattern of nodal enhancement at MRI enhanced with ultrasmall superparamagnetic iron oxide (USPIO) in the nodal classification of rectal cancer in pathologically matched mesorectal lymph nodes. SUBJECTS AND METHODS:Twenty-five patients with adenocarcinoma of the rectum underwent prospective evaluation with 3-mm axial T2-weighted and USPIO-enhanced T2*-weighted MRI before surgery. Mesorectal nodes visible at in vivo MRI were independently scored by two radiologists as malignant or nonmalignant according to morphologic criteria (irregular nodal contour, heterogeneous signal intensity) on T2-weighted MR images and according to USPIO enhancement pattern on T2*-weighted MR images. The sensitivity, specificity, and positive and negative predictive values of morphologic and USPIO criteria in identification of malignancy in the pathologically matched mesorectal nodes were compared by use of the McNemar test. Interobserver agreement was compared by use of kappa statistics. RESULTS:After surgery, radiologic-pathologic comparison of 126 mesorectal nodes (116 benign, 10 malignant) was possible. Use of morphologic criteria resulted in an average sensitivity of 65% (95% CI, 35-88%); specificity, 75% (67-83%); positive predictive value, 19% (8-34%); and negative predictive value, 96% (91-99%). Use of USPIO criteria resulted in an average sensitivity of 65% (95% CI, 35-88%); specificity, 93% (87-96%); positive predictive value, 43% (21-67%); and negative predictive value, 97% (92-99%). Use of USPIO MRI improved diagnostic specificity for both observers (p < 0.01). Interobserver agreement was fair for morphologic criteria (kappa = 0.39) but good for USPIO criteria (kappa = 0.68). CONCLUSION:Use of the pattern of USPIO enhancement had higher diagnostic specificity than but the same sensitivity as morphologic findings in pathologically matched mesorectal lymph nodes.
Distribution of mesorectal lymph nodes in rectal cancer: in vivo MR imaging compared with histopathological examination. Initial observations.
Koh D M,Brown G,Temple L,Blake H,Raja A,Toomey P,Bett N,Farhat S,Norman A R,Daniels I,Husband J E
The aim of this work was to determine the distribution of mesorectal lymph nodes using T2-weighted magnetic resonance (MR) imaging compared with histopathological findings in patients with rectal carcinoma. Sixteen patients with rectal carcinoma undergoing primary surgery without pre-operative neoadjuvant treatment were evaluated using 3-mm axial T2-weighted MR imaging. The position of each visible mesorectal node on imaging was localised by measuring its minimum distance from the mesorectal fascia (d(m)), its minimum distance from the rectal wall (d(r)) and its distance from the distal tumour margin (d(v)). Independent assessment of d(m), d(r) and d(v) was made at histopathological examination. Eighty-five mesorectal nodes on in vivo MR imaging were matched to histopathological findings. On imaging, 67/85 mesorectal nodes were found at the level of the tumour and 84/85 were identified at or within 5 cm proximal to the tumour. Only one out of 85 nodes was seen below the inferior tumour margin. The mean difference of d(m) and d(r) obtained on in vivo MR imaging and histopathological examination was 0.7 mm (95% confidence interval, CI, -0.12 to 1.42 mm) and -1.1 mm (95% CI -2.29 to 0.14 mm), respectively. Almost all mesorectal nodes visible on MR imaging were found at the level of tumour or within 5 cm proximal to the tumour. This has implications for the planning of MR imaging and the level of mesorectal transection at surgery.
Prediction of nodal involvement in primary rectal carcinoma without invasion to pelvic structures: accuracy of preoperative CT, MR, and DWIBS assessments relative to histopathologic findings.
Zhou Jun,Zhan Songhua,Zhu Qiong,Gong Hangjun,Wang Yidong,Fan Desheng,Gong Zhigang,Huang Yanwen
OBJECTIVE:To investigate the accuracy of preoperative computed tomography (CT), magnetic resonance (MR) imaging and diffusion-weighted imaging with background body signal suppression (DWIBS) in the prediction of nodal involvement in primary rectal carcinoma patients in the absence of tumor invasion into pelvic structures. METHODS AND MATERIALS:Fifty-two subjects with primary rectal cancer were preoperatively assessed by CT and MRI at 1.5 T with a phased-array coil. Preoperative lymph node staging with imaging modalities (CT, MRI, and DWIBS) were compared with the final histological findings. RESULTS:The accuracy of CT, MRI, and DWIBS were 57.7%, 63.5%, and 40.4%. The accuracy of DWIBS with higher sensitivity and negative predictive value for evaluating primary rectal cancer patients was lower than that of CT and MRI. Nodal staging agreement between imaging and pathology was fairly strong for CT and MRI (Kappa value = 0.331 and 0.348, P<0.01) but was relatively weaker for DWIBS (Kappa value = 0.174, P<0.05). The accuracy was 57.7% and 59.6%, respectively, for CT and MRI when the lymph node border information was used as the criteria, and was 57.7% and 61.5%, respectively, for enhanced CT and MRI when the lymph node enhancement pattern was used as the criteria. CONCLUSION:MRI is more accurate than CT in predicting nodal involvement in primary rectal carcinoma patients in the absence of tumor invasion into pelvic structures. DWIBS has a great diagnostic value in differentiating small malignant from benign lymph nodes.
Rectal cancer: mesorectal lymph nodes at MR imaging with USPIO versus histopathologic findings--initial observations.
Koh Dow-Mu,Brown Gina,Temple Louis,Raja Asraf,Toomey Paul,Bett Nicholas,Norman Andrew R,Husband Janet E
PURPOSE:To compare histopathologic findings with appearances of mesorectal lymph nodes at magnetic resonance (MR) imaging with ultrasmall particles of iron oxide (USPIO) in rectal cancer. MATERIALS AND METHODS:Mesorectal lymph nodes in 12 patients with adenocarcinoma of the rectum were evaluated with USPIO and high-spatial-resolution MR imaging. Appearance and signal intensity of lymph nodes at T2- and T2*-weighted imaging were recorded before and after USPIO administration. Two radiologists visually assessed pattern of enhancement; interobserver agreement was tested with the kappa statistic. After total mesorectal excision, MR imaging of surgical specimens was performed, and it enabled node-by-node correlation with histopathologic findings. RESULTS:Appearances of 74 nodes at in vivo MR imaging were compared with histopathologic findings. Sixty-eight nodes were nonmalignant (34 were normal, 34 showed reactive changes); six nodes were malignant. Four patterns of USPIO uptake were demonstrated at T2*-weighted imaging: uniform low signal intensity, central low signal intensity, eccentric high signal intensity, and uniform high signal intensity. Two radiologists showed good interobserver agreement (kappa = 0.88, P <.01) in classification of nodes into these four categories. Sixty-five (96%) of 68 nonmalignant nodes showed uniform or central low-signal-intensity patterns; 16 (47%) of 34 reactive nodes showed central low-signal-intensity patterns. Compared with uniform low-signal-intensity pattern, central low-signal-intensity pattern was more commonly observed in reactive nodes (P <.01, chi(2) test; positive predictive value, 67%; 95% CI: 47%, 87%). Eccentric and uniform high-signal-intensity patterns were observed in lymph nodes that contained metastases larger than 1 mm in diameter. CONCLUSION:Mesorectal lymph nodes can be characterized by using USPIO and T2*-weighted MR imaging. Uniform and central low-signal-intensity patterns are features of nonmalignant nodes. Reactive nodes frequently show central low signal intensity at T2*-weighted imaging.
Preoperative evaluation of pelvic lateral lymph node of patients with lower rectal cancer: comparison study of MR imaging and CT in 53 patients.
Arii Kazuo,Takifuji Katsunari,Yokoyama Shozo,Matsuda Kenji,Higashiguchi Takashi,Tominaga Toshiji,Oku Yoshimasa,Tani Masaji,Yamaue Hiroki
Langenbeck's archives of surgery
BACKGROUND:Preoperative assessment of the lateral pelvic lymph nodes is important for treatment strategy to patients with lower rectal cancer. MATERIALS AND METHODS:Fifty-three patients with primary lower rectal cancer were preoperatively assessed by spiral computed tomography (CT) and magnetic resonance imaging (MRI) at 1.5 T with a phased-array coil. Preoperative tumor and lymph node stages were compared with the final histological findings. RESULTS:The MRI tumor stage coincided with the histological stage in 36 of 53 patients (68%). The MRI and CT lymph node stage coincided with the histological stage in 33 (62%) and 26 (49%) of 53 patients, respectively. However the accuracy of MRI in detecting the lateral pelvic lymph node involvement was 83%, compared to 77% of CT (p<0.05). CONCLUSIONS:With the use of MRI, the lateral pelvic lymph node involvement can be predicted with high accuracy, allowing preoperative identification of patients who need radiotherapy or extensive surgery to escape recurrence.
USPIO-enhanced MRI of pelvic lymph nodes at 7-T: preliminary experience.
Philips Bart W J,Stijns Rutger C H,Rietsch Stefan H G,Brunheim Sascha,Barentsz Jelle O,Fortuin Ansje S,Quick Harald H,Orzada Stephan,Maas Marnix C,Scheenen Tom W J
PURPOSE:To evaluate the technical feasibility of high-resolution USPIO-enhanced magnetic resonance imaging of pelvic lymph nodes (LNs) at ultrahigh magnetic field strength. MATERIALS AND METHODS:The ethics review board approved this study and written informed consent was obtained from all patients. Three patients with rectal cancer and three selected patients with (recurrent) prostate cancer were examined at 7-T 24-36 h after intravenous ferumoxtran-10 administration; rectal cancer patients also received a 3-T MRI. Pelvic LN imaging was performed using the TIAMO technique in combination with water-selective multi-GRE imaging and lipid-selective GRE imaging with a spatial resolution of 0.66 × 0.66 × 0.66mm. T-weighted images of the water-selective imaging were computed from the multi-GRE images at TE = 0, 8, and 14 ms and used for the assessment of USPIO uptake. RESULTS:High-resolution 7-T MR gradient-echo imaging was obtained robustly in all patients without suffering from RF-related signal voids. USPIO signal decay in LNs was visualized using computed TE imaging at TE = 8 ms and an R map derived from water-selective imaging. Anatomically, LNs were identified on a combined reading of computed TE = 0 ms images from water-selective scans and images from lipid-selective scans. A range of 3-48 LNs without USPIO signal decay was found per patient. These LNs showed high signal intensity on computed TE = 8 and 14 ms imaging and low R (corresponding to high T) values on the R map. CONCLUSION:USPIO-enhanced MRI of the pelvis at 7-T is technically feasible and offers opportunities for detecting USPIO uptake in normal-sized LNs, due to its high intrinsic signal-to-noise ratio and spatial resolution. KEY POINTS:• USPIO-enhanced MRI at 7-T can indicate USPIO uptake in lymph nodes based on computed TE images. • Our method promises a high spatial resolution for pelvic lymph node imaging.
Imaging and Management of Rectal Cancer.
Arya Supreeta,Sen Saugata,Engineer Reena,Saklani Avanish,Pandey Tarun
Seminars in ultrasound, CT, and MR
High-resolution phased array external magnetic resonance imaging (MRI) is the first investigation of choice in rectal cancer for local staging, both in the primary and restaging situations. Use of MRI helps differentiate between those with good prognosis, which can be offered upfront surgery and the poor prognostic cases where treatment intensification is needed. MRI identified poor prognostic factors are threatened or involved mesorectal fascia, T3 tumors with >5 mm extramural spread, those with extramural vascular invasion, pelvic sidewall nodes and mucinous tumors. At restaging, use of MRI helps evaluate response and an MR tumor regression grading system is being evaluated. Complete response seen on clinical examination and endoscopy, needs confirmation on MRI using both T2-weighted and diffusion-weighted sequences to justify a "watch and wait" approach. In this subset of patients, MRI also plays a role in monitoring and detecting early regrowth. In those with partial response, MRI helps define surgical margins and can be used as a roadmap to decide between sphincter preserving surgeries and radical sphincter sacrificing surgeries; pelvic exenteration and pelvic sidewall lymph node dissection. Poor responders on MRI may benefit from adjuvant chemotherapy. Use of MRI thus helps in individualizing treatment in rectal cancer.
Location of involved mesorectal and extramesorectal lymph nodes in patients with primary rectal cancer: preoperative assessment with MR imaging.
Engelen S M E,Beets-Tan R G H,Lahaye M J,Kessels A G H,Beets G L
European journal of surgical oncology : the journal of the European Society of Surgical Oncology and the British Association of Surgical Oncology
AIM:The purpose of this study is to evaluate the location of involved mesorectal and extramesorectal lymph nodes as depicted on preoperative MRI. Preoperative availability of this information might be useful for the surgeon as well as the radiation therapist and medical oncologist for optimal treatment strategy: type and extent of neoadjuvant treatment as well as extent of surgical resection. METHODS:Forty-one patients with biopsy-proven rectal cancer were included. All patients underwent preoperative MRI using USPIO (lymph node specific contrast agent). Location of all mesorectal and extramesorectal nodes visible on MRI was recorded, as well as USPIO prediction on nodal status. Lesion-by-lesion analysis using histology after surgery was performed for patients who did not receive long course chemoradiation therapy. RESULTS:There were 438 nodes visible, 94 of which were malignant. Most nodes are located in the laterodorsal part of the mesorectum, with no difference in distribution between positive and negative nodes. In relation to height of tumor, the majority of positive nodes are located at tumor height or above. There were significantly more negative nodes (9.6%) located below tumor height as compared to positive nodes (2.1%). There were 40 extramesorectal nodes, in 16 patients, 5 of which were positive in 4 patients. All patients had distal rectal cancer. CONCLUSION:In conclusion, positive mesorectal nodes are located in the laterodorsal part of the mesorectum, at tumor height or above. Positive nodes distal to the tumor are rare, and occur in patients with more proximal nodal metastases. Positive extramesorectal nodes mainly occur in patients with distal rectal cancer with nodal metastases in the mesorectum.
DWI and T2-Weighted MRI Volumetry in Resectable Rectal Cancer: Correlation With Lymphovascular Invasion and Lymph Node Metastases.
Chen Xiao-Li,Chen Guang-Wen,Pu Hong,Yin Long-Lin,Li Zhen-Lin,Song Bin,Li Hang
AJR. American journal of roentgenology
OBJECTIVE:The purpose of this study was to assess whether MR volumetric data on DW and T2-weighted MR images are correlated with lymphovascular invasion and lymph node metastases in resectable rectal cancer. MATERIALS AND METHODS:This retrospective study consisted of 50 consecutive patients with rectal cancer who underwent radical surgery within 1 week of MRI. The gross tumor volume was determined on both diffusion-weighted and T2-weighted MR images and correlated with pathologic lymphovascular invasion and lymph node metastases using univariate, multivariate, and ROC curve analyses. RESULTS:Both gross tumor volume values showed correlations with lymphovascular invasion (r = 0.750 vs r = 0.710; p < 0.0001) and lymph node metastases (r = 0.780 vs r = 0.755; p < 0.0001). Both values were associated with lymphovascular invasion and lymph node metastases in univariate analysis (all p < 0.0001), whereas only the DWI-based value was an independent risk factor for lymphovascular invasion (odds ratio = 1.207; p = 0.005) and lymph node metastases (odds ratio = 1.420; p = 0.005) in multivariate analysis. Both values could distinguish between N0 and N1, N0 and N1-N2, and N0-N1 and N2 disease (all p < 0.0001) in the Mann-Whitney U test. The area under the ROC curve was higher for the DWI-based value in lymphovascular invasion (0.899 vs 0.877), N0 vs N1 (0.865 vs 0.827), N0 vs N1-N2 (0.934 vs 0.911), and N0-N1 vs N2 (0.932 vs 0.927). CONCLUSION:Tumor volumetry data correlated with both lymphovascular invasion and lymph node metastases in resectable rectal cancer. In particular, the DWI-based gross tumor volume showed the most potential for noninvasive preoperative evaluation of lymphovascular invasion and lymph node metastases.
Fat-suppressed gadolinium-enhanced isotropic high-resolution 3D-GRE-T1WI for predicting small node metastases in patients with rectal cancer.
Chen Yan,Yang Xinyue,Wen Ziqiang,Lu Baolan,Xiao Xiaojuan,Shen Bingqi,Yu Shenping
Cancer imaging : the official publication of the International Cancer Imaging Society
BACKGROUND:To investigate the application value of fat-suppressed gadolinium-enhanced isotropic high-resolution 3D-GRE-T1WI in regional nodes with different short-axis diameter ranges in rectal cancer, especially in nodes ≤5 mm. METHODS:Patients with rectal adenocarcinoma confirmed by postoperative histopathology were included, and all the patients underwent preoperative 3.0 T rectal magnetic resonance imaging (MRI) and total mesorectal excision (TME) within 2 weeks after an MR scan. The harvested nodes from specimens were matched with nodes in the field of view (FOV) of images for a node-by-node evaluation. The maximum short-axis diameters of all the visible nodes in the FOV of images were measured by a radiologist; the morphological and enhancement characteristics of these nodes were also independently evaluated by two radiologists. The χ test was used to evaluate differences in morphological and enhancement characteristics between benign and malignant nodes. The enhancement characteristics were further compared between benign and malignant nodes with different short-axis diameter ranges using the χ test. Kappa statistics were used to describe interobserver agreement. RESULTS:A total of 441 nodes from 70 enrolled patients were included in the evaluation, of which 111 nodes were metastatic. Approximately 85.5 and 95.6% of benign nodes were found to have obvious enhancement and homogeneous or mild-heterogeneous enhancement, respectively, whereas approximately 89.2 and 85.1% of malignant nodes showed moderate or mild enhancement and obvious-heterogeneous or rim-like enhancement, respectively. The area under the receiver operating characteristic (ROC) curve (AUC) values of the enhancement degree for identifying the overall nodal status, nodes ≤5 mm and nodes > 5 mm and ≤ 10 mm were 0.887, 0.859 and 0.766 for radiologist 1 and 0.892, 0.823 and 0.774 for radiologist 2, respectively. The AUCs of enhancement homogeneity were 0.940, 0.928 and 0.864 for radiologist 1 and 0.944, 0.938 and 0.842 for radiologist 2, respectively. Nodal border and signal homogeneity were also of certain value in distinguishing metastatic nodes. CONCLUSIONS:Enhancement characteristics based on fat-suppressed gadolinium-enhanced isotropic high-resolution 3D-GRE-T1WI were helpful for diagnosing metastatic nodes in rectal cancer and were a reliable indicator for nodes ≤5 mm.
A computer-aided algorithm to quantitatively predict lymph node status on MRI in rectal cancer.
Tse D M L,Joshi N,Anderson E M,Brady M,Gleeson F V
The British journal of radiology
OBJECTIVE:The aim of this study was to demonstrate the principle of supporting radiologists by using a computer algorithm to quantitatively analyse MRI morphological features used by radiologists to predict the presence or absence of metastatic disease in local lymph nodes in rectal cancer. METHODS:A computer algorithm was developed to extract and quantify the following morphological features from MR images: chemical shift artefact; relative mean signal intensity; signal heterogeneity; and nodal size (volume or maximum diameter). Computed predictions on nodal involvement were generated using quantified features in isolation or in combinations. Accuracies of the predictions were assessed against a set of 43 lymph nodes, determined by radiologists as benign (20 nodes) or malignant (23 nodes). RESULTS:Predictions using combinations of quantified features were more accurate than predictions using individual features (0.67-0.86 vs 0.58-0.77, respectively). The algorithm was more accurate when three-dimensional images were used (0.58-0.86) than when only middle image slices (two-dimensional) were used (0.47-0.72). Maximum node diameter was more accurate than node volume in representing the nodal size feature; combinations including maximum node diameter gave accuracies up to 0.91. CONCLUSION:We have developed a computer algorithm that can support radiologists by quantitatively analysing morphological features of lymph nodes on MRI in the context of rectal cancer nodal staging. We have shown that this algorithm can combine these quantitative indices to generate computed predictions of nodal status which closely match radiological assessment. This study provides support for the feasibility of computer-assisted reading in nodal staging, but requires further refinement and validation with larger data sets.
Prediction of tumor stage and lymph node involvement with dynamic contrast-enhanced MRI after chemoradiotherapy for locally advanced rectal cancer.
Alberda Wijnand J,Dassen Helene P N,Dwarkasing Roy S,Willemssen François E J A,van der Pool Anne E M,de Wilt Johannes H W,Burger Jacobus W A,Verhoef Cornelis
International journal of colorectal disease
PURPOSE:The usefulness of restaging by magnetic resonance imaging (MRI) after chemoradiotherapy (CTx/RTx) in patients with locally advanced rectal cancer has not yet been established, mostly due to the difficult differentiation between viable tumor and fibrosis. MRI with dynamic contrast-enhanced (DCE) sequences may be of additional value in distinguishing malignant from nonmalignant tissue. The aim of this study was to assess the accuracy of tumor, nodal staging, and circumferential resection margin (CRM) involvement by MRI with DCE sequences after CTx/RTx. METHODS:The accuracies were assessed by MRI on T2-weighted magnetic resonance (MR) images with DCE sequences in patients with locally advanced rectal cancer after a long course of CTx/RTx. MR images were assessed by two independent radiologists. RESULTS:For tumor staging and CRM involvement, MRI with DCE sequences had an accuracy of 45 and 60 %, respectively. The accuracy for nodal staging was 93 %. On MRI, malignant lymph nodes had a median diameter of 8 mm (range, 4-18) and benign lymph nodes a median diameter of 4 mm (range, 3-11). A significant indicator for benign nodes was hypointensity on T2-weighted images (p < 0.001) and early complete arterial phase enhancement on DCE-weighted images (p < 0.001). A significant indicator for malignant nodes was heterogeneity on T2-weighted images (χ (2), p < 0.000) and early incomplete arterial phase enhancement on DCE (p < 0.001). CONCLUSIONS:MRI with DCE is a useful tool for nodal staging after CTx/RTx. The addition of DCE sequences did not improve the accuracy of determining the tumor stage, CRM involvement, and in detecting complete response.
A magnetic resonance imaging (MRI)-based nomogram for predicting lymph node metastasis in rectal cancer: a node-for-node comparative study of MRI and histopathology.
Liu Yuan,Wan Lijuan,Peng Wenjing,Zou Shuangmei,Zheng Zhaoxu,Ye Feng,Jiang Jun,Ouyang Han,Zhao Xinming,Zhang Hongmei
Quantitative imaging in medicine and surgery
Background:The aim of the present study was to investigate the potential risk factors for lymph node metastasis (LNM) in rectal cancer using magnetic resonance imaging (MRI), and to construct and validate a nomogram to predict its occurrence with node-for-node histopathological validation. Methods:Our prediction model was developed between March 2015 and August 2016 using a prospective primary cohort (32 patients, mean age: 57.3 years) that included 324 lymph nodes (LNs) from MR images with node-for-node histopathological validation. We evaluated multiple MRI variables, and a multivariable logistic regression analysis was used to develop the predictive nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. The performance of the nomogram in predicting LNM was validated in an independent clinical validation cohort comprising 182 consecutive patients. Results:The predictors included in the individualized prediction nomogram were chemical shift effect (CSE), nodal border, short-axis diameter of nodes, and minimum distance to rectal cancer or rectal wall. The nomogram showed good discrimination (C-index: 0.947; 95% confidence interval: 0.920-0.974) and good calibration in the primary cohort. Decision curve analysis confirmed the clinical usefulness of the nomogram in predicting the status of each LN. For the prediction of LN status in the clinical validation cohort by readers 1 and 2, the areas under the curves using the nomogram were 0.890 and 0.841, and the areas under the curves of readers using their experience were 0.754 and 0.704, respectively. Diagnostic efficiency was significantly improved by using the nomogram (P<0.001). Conclusions:The nomogram, which incorporates CSE, nodal location, short-axis diameter, and minimum distance to rectal cancer or rectal wall, can be conveniently applied in clinical practice to facilitate the prediction of LNM in patients with rectal cancer.
Diffusion-weighted MR imaging in primary rectal cancer staging demonstrates but does not characterise lymph nodes.
Heijnen Luc A,Lambregts Doenja M J,Mondal Dipanjali,Martens Milou H,Riedl Robert G,Beets Geerard L,Beets-Tan Regina G H
OBJECTIVES:To evaluate the performance of diffusion-weighted MRI (DWI) for the detection of lymph nodes and for differentiating between benign and metastatic nodes during primary rectal cancer staging. METHODS:Twenty-one patients underwent 1.5-T MRI followed by surgery (± preoperative 5 × 5 Gy). Imaging consisted of T2-weighted MRI, DWI (b0, 500, 1000), and 3DT1-weighted MRI with 1-mm isotropic voxels. The latter was used for accurate detection and per lesion histological validation of nodes. Two independent readers analysed the signal intensity on DWI and measured the mean apparent diffusion coefficient (ADC) for each node (ADCnode) and the ADC of each node relative to the mean tumour ADC (ADCrel). RESULTS:DWI detected 6 % more nodes than T2W-MRI. The signal on DWI was not accurate for the differentiation of metastatic nodes (AUC 0.45-0.50). Interobserver reproducibility for the nodal ADC measurements was excellent (ICC 0.93). Mean ADCnode was higher for benign than for malignant nodes (1.15 ± 0.24 vs. 1.04 ± 0.22 *10(-3) mm(2)/s), though not statistically significant (P = 0.10). Area under the ROC curve/sensitivity/specificity for the assessment of metastatic nodes were 0.64/67 %/60 % for ADCnode and 0.67/75 %/61 % for ADCrel. CONCLUSIONS:DWI can facilitate lymph node detection, but alone it is not reliable for differentiating between benign and malignant lymph nodes.
[Diagnosis value of 3.0 T diffusion-weighted imaging with background suppression magnetic resonance for metastatic lymph nodes in rectal cancer].
Zhuang Xiao-zhao,Yu Shen-ping,Cui Ji,Chen Chuang-qi,Zhao Xiao-juan,Pan Bi-tao,Li Zi-ping
Zhonghua wei chang wai ke za zhi = Chinese journal of gastrointestinal surgery
OBJECTIVE:To evaluate the diagnostic value of 3.0 T diffusion-weighted imaging with background suppression (DWIBS) magnetic resonance (MR) for lymph node metastasis in rectal cancer. METHODS:Thirty-five patients with rectal cancer who underwent preoperative routine MRI+DWI examination were enrolled in the study and were treated by rectal cancer resection plus lymph node dissection. Metastatic and non-metastatic lymph nodes were confirmed by postoperative pathology. Apparent diffusion coefficient (ADC) values, long-axis and short-axis diameters of lymph nodes were measured. Receiver operating characteristic (ROC) curve was used to assess the diagnostic efficacy of ADC, long-axis and short-axis diameters for differentiating metastatic lymph nodes from non-metastatic lymph nodes. RESULTS:A total of 151 lymph nodes were confirmed with exact location in 35 patients. Sixty-five metastatic lymph nodes and 86 non-metastatic lymph nodes were identified. The ADC values of metastatic lymph nodes and non-metastatic lymph nodes were(0.86±0.14)×10(-3) and (0.94±0.16)×10(-3) mm(2)/s respectively. The long-axis diameter were(9.78±3.13) and (7.90±1.77) mm, respectively. The short-axis diameter were (7.65±2.00) and (6.45±1.19) mm, respectively. There were statistically significant differences between metastatic and non-metastatic lymph nodes in ADC values, long-axis diameter, and short-axis diameter(all P<0.01). The areas under the ROC curve of ADC value, long-axis diameter, and short-axis diameter were 0.648, 0.706, and 0.692, respectively. Optimal cutoff values for these parameters were 1.05×10(-3) mm(2)/s, 7.95 mm, and 5.90 mm, respectively, and the corresponding sensitivities and specificities were 93.8% and 30.2%, 75.4% and 61.6%, 90.8% and 38.4%. CONCLUSIONS:Quantitative measurement of ADC value may reflect the degree of diffusion restriction of metastatic lymph nodes by DWIBS at 3.0 T MR. Accurate diagnosis of metastatic lymph nodes in rectal cancer demands comprehensive evaluation combining ADC value with diameter measurement.
Utility of texture analysis on T2-weighted MR for differentiating tumor deposits from mesorectal nodes in rectal cancer patients, in a retrospective cohort.
Atre Isha D,Eurboonyanun Kulyada,Noda Yoshifumi,Parakh Anushri,O'Shea Aileen,Lahoud Rita Maria,Sell Naomi M,Kunitake Hiroko,Harisinghani Mukesh G
Abdominal radiology (New York)
OBJECTIVE:The purpose of the study was to evaluate the utility of MR texture analysis for differentiating tumor deposits from mesorectal nodes in rectal cancer. MATERIALS AND METHODS:Pretreatment MRI of 40 patients performed between 2006 and 2018 with pathologically proven tumor deposits and/or malignant nodes in the setting of rectal cancer were retrospectively reviewed. In total, 25 tumor deposits (TDs) and 71 positive lymph nodes (LNs) were analyzed for morphological and first-order texture analysis features on T2-weighted axial images. MR morphological features (lesion shape, size, signal heterogeneity, contrast enhancement) were analyzed and agreed in consensus by two experienced radiologists followed by assessment with Fisher's exact test. Texture analysis of the lesions was performed using TexRAD, a proprietary software algorithm. First-order texture analysis features (mean, standard deviation, skewness, entropy, kurtosis, MPP) were obtained after applying spatial scaling filters (SSF; 0, 2, 3, 4, 5, 6). Univariate analysis was performed with non-parametric Mann-Whitney U test. The results of univariate analysis were reassessed with generalized estimating equations followed by multivariate analysis. Using histopathology as a gold standard, diagnostic accuracy was assessed by obtaining area under the receiver operating curve. RESULTS:MR morphological parameter, lesion shape was a strong discriminator between TDs and LNs with a p value of 0.02 (AUC: 0.76, 95% CI of 0.66 to 0.84, SE: 0.06) and sensitivity, specificity of 90% and 68%, respectively. Skewness extracted at fine filter (SSF-2) was the only significant texture analysis parameter for distinguishing TDs from LNs with p value of 0.03 (AUC: 0.70, 95% CI of 0.59 to 0.79, SE: 0.06) and sensitivity, specificity of 70% and 72%, respectively. When lesion shape and skewness-2 were combined into a single model, the diagnostic accuracy was improved with AUC of 0.82 (SE: 0.05, 95% CI of 0.72 to 0.88 with p value of < 0.01). This model also showed a high sensitivity of 91% with specificity of 68%. CONCLUSION:Lesion shape on MR can be a useful predictor for distinguishing TDs from positive LNs in rectal cancer patients. When interpreted along with MR texture parameter of skewness, accuracy is further improved.
Correlation of MRI-detected extramural vascular invasion with regional lymph node metastasis in rectal cancer.
Liu Liheng,Liu Ming,Yang Zhenghan,He Wen,Wang Zhenchang,Jin Erhu
AIM:To evaluate the value of magnetic resonance imaging-detected extramural vascular invasion (MR-EMVI) in predicting regional lymph node metastasis (RLNM) in patients with rectal cancer. METHODS:A total of 183 patients were included. A set of clinical and imaging factors including MR-EMVI were evaluated using univariate and multivariate analyses to determine the risk factors for RLNM. RESULTS:Among the clinical and imaging factors evaluated, MR-EMVI, pathologic EMVI, nodal size, and diffusion-weighted imaging-detected positive nodes were independent predictors of RLNM. CONCLUSIONS:MR-EMVI may be an independent predictor of RLNM in patients with rectal cancer.
Can Ex Vivo Magnetic Resonance Imaging of Rectal Cancer Specimens Improve the Mesorectal Lymph Node Yield for Pathological Examination?
Stijns Rutger,Philips Bart,Wauters Carla,de Wilt Johannes,Nagtegaal Iris,Scheenen Tom
PURPOSE:The aim of this study was to use 7 T ex vivo magnetic resonance imaging (MRI) scans to determine the size of lymph nodes (LNs) in total mesorectal excision (TME) specimens and to increase the pathological yield of LNs with MR-guided pathology. MATERIALS AND METHODS:Twenty-two fixated TME specimens containing adenocarcinoma were scanned on a 7 T preclinical MRI system with a T1-weighted 3-dimensional gradient echo sequence with frequency-selective lipid excitation (repetition time/echo time, 15/3 milliseconds; resolution, 0.293 mm) and a water-excited 3-dimensional multigradient echo (repetition time, 30 milliseconds; computed echo time, 6.2 milliseconds; resolution, 0.293 mm) pulse sequence.The first series of 11 TME specimens (S1) revealed the number and size of LNs on both ex vivo MRI and histopathology. The second series of 11 TME specimens (S2) was used to perform MR-guided pathology. The number, size, and percentages of yielded LNs of S1 and S2 were compared. RESULTS:In all specimens (22/22), a median number of 34 LNs (interquartile range, 26-34) was revealed on ex vivo MRI compared with 14 LNs (interquartile range, 7.5-21.5) on histopathology (P = 0.003). Mean size of all LNs did not differ between the 2 series (ex vivo MRI: 2.4 vs 2.5 mm, P = 0.267; pathology: 3.6 vs 3.5 mm, P = 0.653). The median percentages of harvested LNs compared with nodes visible on ex vivo MRI per specimen for both series were not significantly different (40% vs 43%, P = 0.718). By using a size threshold of greater than 2 mm, the percentage improved to 71% (S1) and to 78% (S2, P = 0.895). The median number of harvested LNs per specimen did not increase by performing MR-guided pathology (S1, 14 LNs; S2, 20 LNs; P = 0.532). CONCLUSIONS:Ex vivo MRI visualizes more LNs than (MR-guided) pathology is able to harvest. Current pathological examination was not further improved by MR guidance. The majority of LNs or LN-like structures visible on ex vivo MRI below 2 mm in size remain unexplained, which warrants a 3-dimensional approach for pathological reconstruction of specimens.
Non-invasive MR assessment of the microstructure and microcirculation in regional lymph nodes for rectal cancer: a study of intravoxel incoherent motion imaging.
Yang Xinyue,Chen Yan,Wen Ziqiang,Liu Yiyan,Xiao Xiaojuan,Liang Wen,Yu Shenping
Cancer imaging : the official publication of the International Cancer Imaging Society
BACKGROUND:The aim of this study is to evaluate the microstructure and microcirculation of regional lymph nodes (LNs) in rectal cancer by using non-invasive intravoxel incoherent motion MRI (IVIM-MRI), and to distinguish metastatic from non-metastatic LNs by quantitative parameters. METHODS:All recruited patients underwent IVIM-MRI (b = 0, 5, 10, 20, 30, 40, 60, 80, 100, 150, 200, 400, 600, 1000, 1500 and 2000 s/mm) on a 3.0 T MRI system. One hundred sixty-eight regional LNs with a short-axis diameter equal to or greater than 5 mm from 116 patients were evaluated by two radiologists independently, including 78 malignant LNs and 90 benign LNs. The following parameters were assessed: the short-axis diameter (S), long-axis diameter (L), short- to long-axis diameter ratio (S/L), pure diffusion coefficient (D), pseudo-diffusion coefficient (D), and perfusion factor (f). Intraclass correlation coefficients (ICCs) were calculated to assess the interobserver agreement between two readers. Receiver operating characteristic curves were applied for analyzing statistically significant parameters. RESULTS:Interobserver agreement of IVIM-MRI parameters between two readers was excellent (ICCs> 0.75). The metastatic group exhibited higher S, L and D (P < 0.001), but lower f (P < 0.001) than the non-metastatic group. The area under the curve (95% CI, sensitivity, specificity) of the multi-parameter combined equation for D, f and S was 0.811 (0.744~0.868, 62.82%, 87.78%). The diagnostic performance of the multi-parameter model was better than that of an individual parameter (P < 0.05). CONCLUSION:IVIM-MRI parameters provided information about the microstructure and microcirculation of regional LNs in rectal cancer, also improved diagnostic performance in identifying metastatic LNs.
Prediction of lateral pelvic lymph node metastasis in patients with locally advanced rectal cancer with preoperative chemoradiotherapy: Focus on MR imaging findings.
Kim Min Ju,Hur Bo Yun,Lee Eun Sun,Park Boram,Joo Jungnam,Kim Min Jung,Park Sung Chan,Baek Ji Yeon,Chang Hee Jin,Kim Dae Yong,Oh Jae Hwan
PURPOSE:To investigate the predictive factors for lateral pelvic lymph node (LPLN) metastasis in patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy (CRT). MATERIALS AND METHODS:Fifty-seven patients with locally advanced rectal cancer and LPLNs larger than 5 mm underwent LPLN dissection (LPLD) after preoperative CRT. The MRI findings, including the apparent diffusion coefficient value and LPLN size reduction rate before/after CRT; clinical factors; and pathologic results were evaluated to identify the predictive factors associated with LPLN metastasis. RESULTS:LPLN metastasis was confirmed in 23 patients (40.4%). Metastasis was significantly higher in LPLNs with multiplicity, short-axis diameter ≥8 mm before CRT, short-axis diameter >5 mm after CRT, size reduction rate ≤33.3%, heterogeneous signal intensity, and irregular margin (P<0.05) on MR. Multivariable analysis showed that pre-CRT short-axis diameter of LPLNs ≥8 mm, size reduction rate ≤33.3%, and heterogeneous signal intensity were independently associated with LPLN metastasis. CONCLUSIONS:The size and signal intensity of LPLN before and after CRT are useful MRI findings to predict LPLN metastasis and are helpful to determine the indications for LPLD.
Assessment of remaining tumour involved lymph nodes with MRI in patients with complete luminal response after neoadjuvant treatment of rectal cancer.
Loftås Per,Sturludóttir Margrét,Hallböök Olof,Almlöv Karin,Arbman Gunnar,Blomqvist Lennart
The British journal of radiology
OBJECTIVE:To assess the accuracy of MRI to predict remaining lymph node metastases in patients with complete pathological luminal response (ypT0) after neoadjuvant therapy. METHODS:Data from a national registry were used. 19 patients with histopathologically remaining lymph node metastases (ypT0N+) were identified. Another 19 patients without lymph node metastases (ypT0N0) were used as matched controls. Two radiologists blinded to all patient information evaluated staging and restaging MRI that was compared to histopathological findings of the resected specimen. RESULTS:The average size of the largest lymph node on restaging MRI was significantly larger (4.5 mm) in the ypT0N+ group than in the ypT0N0 group (2.6 mm) (p = 0.04). Presence of ypN+ was correctly predicted by MRI in 7 of 19 patients. In patients without lymph node metastases (ypT0N0), these were correctly classified by MRI in 16 of 19 patients. All patients who had MR-identified lymph nodes larger than 8 mm at restaging were ypTN+. The sensitivity, specificity, positive predictive value and negative for prediction of remaining lymph node metastasis with MRI were 37, 84, 70 and 57%. CONCLUSION:In patients with ypT0 in rectal cancer after neoadjuvant treatment, remaining regional lymph node metastases cannot safely be predicted by restaging MRI alone using presently known criteria. Presence of a lymph node over 8 mm on restaging MRI strongly indicates yPN+. Advances in knowledge: This is one of the first studies on MRI lymph node assessment after chemo-radiotherapy (CRT) in luminal complete response.
Accuracy of Various Lymph Node Staging Criteria in Rectal Cancer with Magnetic Resonance Imaging.
Gröne Jörn,Loch Florian N,Taupitz Matthias,Schmidt C,Kreis Martin E
Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract
INTRODUCTION:The accuracy of pretherapeutic staging of lymph nodes (LN) in rectal cancer by MR imaging (MRI) is still limited. The aim of the study was to determine the sensitivity and specificity of different morphological criteria in nodal staging. MATERIAL AND METHODS:LN were analyzed by MRI in 60 patients with rectal cancer and primary surgery. Signs of LN metastasis (cN+) were spiculated/indistinct border contour, inhomogeneous signal intensity, or LN size. The accuracy of these signs for clinical LN staging was analyzed with conclusive postoperative histological lymph node examination. RESULTS:68.3% of patients with nodal metastasis (pN+) were correctly identified by size with a cutoff value of 7.2 mm. This, however, was not inferior to the 76.7% identified using the inhomogeneous morphological signal intensity and spiculated/indistinct border contour criteria (p = 0.096). 3.3 versus 5% were overstaged, and 28.3 versus 18.3% understaged by these criteria. Sensitivities/specificities for (a) size, (b) spiculated/indistinct border contour, and (c) inhomogeneous signal intensity and spiculated/indistinct border contour were (a) 32%/94%, (b) 56%/86%, and (c) 56%/91%, respectively. CONCLUSIONS:The accuracy of LN staging in rectal cancer was not improved by morphological criteria. These limitations suggest being reticent when recommending neoadjuvant chemoradiation merely based on preoperative positive LN staging.
Lymph node metastasis in rectal cancer: comparison of MDCT and MR imaging for diagnostic accuracy.
Liu Yiyan,Wen Ziqiang,Yang Xinyue,Lu Baolan,Xiao Xiaojuan,Chen Yan,Yu Shenping
Abdominal radiology (New York)
PURPOSE:To compare the diagnostic accuracies of MDCT and high-resolution MRI (HR-MRI) for regional nodal metastases with different short-axis diameter ranges in rectal cancer patients. METHODS:Rectal adenocarcinoma patients who underwent both MDCT and HR-MRI before surgery were included. The maximum short-axis diameters of the nodes were measured, and were classified as benign or malignant on imaging findings. All of the nodes were subdivided as follows: ≤ 5 mm (Group A), > 5 mm and ≤ 10 mm (Group B) , and > 10 mm (Group C). The postoperative pathological reports were used as the standard, and the sensitivity, specificity, accuracy, ROC curve, and AUC value were calculated for each subgroup. RESULTS:A total of 592 nodes were included in the node-to-node evaluation. In Group A, the specificity and accuracy of HR-MRI were significantly higher than those of MDCT (99.28% vs. 93.99%, P < 0.001; 95.78% vs. 89.56%, P = 0.010; respectively). In Group B, the specificity and accuracy of HR-MRI were also higher than those of MDCT (98.36% vs. 55.74%, P < 0.001; 80.45% vs. 66.17%, P < 0.001; respectively). For Groups A and B, the AUCs of MDCT were both 0.65, whereas those of HR-MRI were 0.76 and 0.82, respectively. In Group C, all nine malignant nodes were correctly diagnosed metastases on MDCT, whereas one was misjudged as benign on HR-MRI. CONCLUSIONS:The diagnostic value of HR-MRI is superior to that of MDCT, with higher specificity, accuracy, and AUC values for HR-MRI than for MDCT.
Chemical shift effect predicting lymph node status in rectal cancer using high-resolution MR imaging with node-for-node matched histopathological validation.
Zhang Hongmei,Zhang Chongda,Zheng Zhaoxu,Ye Feng,Liu Yuan,Zou Shuangmei,Zhou Chunwu
OBJECTIVES:To evaluate the value of the chemical shift effect (CSE) as well as other criteria for the prediction of lymph node status. MATERIALS AND METHODS:Twenty-nine patients who underwent radical surgery of rectal cancers were studied with pre- and postoperative specimen MRI. Lymph nodes were harvested from transverse whole-mount specimens and compared with in vivo and ex vivo images to obtain a precise slice-for-section match. Preoperative MR characteristics including CSE, as well as other predictors, were evaluated by two readers independently between benign and metastatic nodes. RESULTS:A total of 255 benign and 35 metastatic nodes were obtained; 71.4% and 69.4% of benign nodes were detected with regular CSE for two readers, whereas 80.0% and 74.3% of metastatic nodes with absence of CSE. The CSE rendered areas under the ROC curve (AUC) of 0.879 and 0.845 for predicting nodal status for two readers. The criteria of nodal location, border, signal intensity and minimum distance to the rectal wall were also useful but with AUCs (0.629-0.743) lower than those of CSE. CONCLUSIONS:CSE is a reliable predictor for differentiating benign from metastatic nodes. Additional criteria should be taken into account when it is difficult to determine the nodal status by using only a single predictor. KEY POINTS:• CSE is good for predicting nodal status with high confidence. • Nodal border and signal intensity are useful for assessing nodal status. • Location of mesorectal nodes could facilitate the prediction of nodal status. • Primary tumour stage could be used as reference for nodal staging.
The prognostic significance of MRI-detected extramural venous invasion, mesorectal extension, and lymph node status in clinical T3 mid-low rectal cancer.
Gu Chaoyang,Yang Xuyang,Zhang Xubing,Zheng Erliang,Deng Xiangbing,Hu Tao,Wu Qingbin,Bi Liang,Wu Bing,Su Minggang,Wang Ziqiang
The purpose of this study was to evaluate the prognostic significance of the magnetic resonance imaging-detected extramural venous invasion (MR-EMVI), the depth of mesorectal extension (MR-DME), and lymph node status (MR-LN) in clinical T3 mid-low rectal cancer. One hundred and forty-six patients with clinical T3 mid-low rectal cancer underwent curative surgery were identified. Pretreatment high-resolution MRI was independently reviewed by two experienced radiologists to evaluate MR-EMVI score (0-4), MR-DME (≤4 mm or >4 mm), and MR-LN (positive or negative). The Cox-multivariate regression analysis revealed that the MR-EMVI was the only independent prognostic factor that correlated with overall 3-year disease-free survival (DFS) (p = 0.01). The survival analysis showed that patients with positive MR-EMVI, MR-DME > 4 mm, and positive MR-LN had a poorer prognosis in the overall 3-year DFS (HR 3.557, 95% CI 2.028 to 13.32, p < 0.01; HR 3.744, 95% CI:1.165 to 5.992, p = 0.002; HR 2.946, 95% CI: 1.386 to 6.699, p < 0.01). By combining MR-EMVI with MR-DME or MR-LN, the prognostic significance was more remarkable. Our study suggested that the MR-EMVI, MR-DME, and MR-LN were the important prognostic factors for patients with clinical T3 mid-low rectal cancer and the MR-EMVI was an independent prognostic factor.
Diffusion-weighted MR volume and apparent diffusion coefficient for discriminating lymph node metastases and good response after chemoradiation therapy in locally advanced rectal cancer.
Yuan Yi,Pu Hong,Chen Guang-Wen,Chen Xiao-Li,Liu Yi-Sha,Liu Hao,Wang Kang,Li Hang
OBJECTIVE:To determine diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) volume and apparent diffusion coefficient values (ADCs) for assessing lymph node metastases (LNM) and good response after chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS:This retrospective study consisted of 61 patients with LARC who underwent pre- and post-CRT DW images. Two radiologists independently placed free-hand regions of interest in each tumor-containing section on DW images to calculate pre- and post-CRT tumor volume and tumor volume reduction rates (Δvolume). Regions of interest were drawn to include tumor on maximum cross-sectional slice to obtain ADCs. Areas under the receiver operating characteristic curves (AUCs) were calculated to evaluate diagnostic performance in identifying LNM and good response after CRT using these parameters. RESULTS:Inter-observer agreement and intra-observer agreement were excellent for pre- and post-CRT DW MR volume (intraclass correlation coefficient [ICC], 0.889-0.948) and moderate for pre- and post-CRT ADCs (ICC, 0.535-0.811). AUCs for identifying LNM were 0.508 for pre-CRT DW MR volume versus 0.705 for pre-CRT ADC, 0.855 for post-CRT DW MR volume versus 0.679 for post-CRT ADC, and 0.887 for Δvolume versus 0.533 for ΔADC. AUCs for identifying good response were 0.518 for pre-CRT volume versus 0.506 for pre-CRT ADC, 0.975 for post-CRT volume versus 0.723 for post-CRT ADC, and 0.987 for Δvolume versus 0.655 for ΔADC. CONCLUSION:DW MR Δvolume provided high diagnostic performance in discriminating LNM after CRT. DW MR Δvolume was equally as accurate as post-CRT DW MR volume for evaluating good response. KEY POINTS:• Inter-observer agreement and intra-observer agreement were excellent for pre- and post-CRT DW MR volume (intraclass correlation coefficient [ICC], 0.889-0.948) and moderate for pre- and post-CRT ADCs (ICC, 0.535-0.811). • DW MR Δvolume provided high diagnostic performance in identifying LNM after CRT (AUC, 0.887) and good response (AUC, 0.987) and was significantly more accurate than pre-CRT DW MR volume (AUC, 0.508 and 0.518, respectively) and ADCs (AUC, 0.705 and 0.506, respectively). • DW MR Δvolume (AUC, 0.987) was equally as accurate as post-CRT DW MR volume (AUC, 0.975) for evaluating good response, while pre-CRT DW MR volume and ADCs were not reliable for evaluating LNM and good response after CRT (AUC, 0.506-0.723).
Prediction Model Combining Clinical and MR Data for Diagnosis of Lymph Node Metastasis in Patients With Rectal Cancer.
Xu Hanshan,Zhao Wenyuan,Guo Wenbing,Cao Shaodong,Gao Chao,Song Tiantian,Yang Liping,Liu Yanlong,Han Yu,Zhang Lingbo,Wang Kezheng
Journal of magnetic resonance imaging : JMRI
BACKGROUND:Determining the status of lymph node (LN) metastasis in rectal cancer patients preoperatively is crucial for the treatment option. However, the diagnostic accuracy of current imaging methods is low. PURPOSE:To develop and test a model for predicting metastatic LNs of rectal cancer patients based on clinical data and MR images to improve the diagnosis of metastatic LNs. STUDY TYPE:Retrospective. SUBJECTS:In all, 341 patients with histologically confirmed rectal cancer were divided into one training set (120 cases) and three validation sets (69, 103, 49 cases). FIELD STRENGTH/SEQUENCE:3.0T, axial and sagittal T -weighted turbo spin echo and diffusion-weighted imaging (b = 0 s/mm , 800 s/mm ) ASSESSMENT: In the training dataset, univariate logistic regression was used to identify the clinical factors (age, gender, and tumor markers) and MR data that correlated with LN metastasis. Then we developed a prediction model with these factors by multiple logistic regression analysis. The accuracy of the model was verified using three validation sets and compared with the traditional MRI method. STATISTICAL TESTS:Univariate and multivariate logistic regression. The area under the curve (AUC) value was used to quantify the diagnostic accuracy of the model. RESULTS:Eight factors (CEA, CA199, ADCmean, mriT stage, mriN stage, CRM, EMVI, and differentiation degree) were significantly associated with LN metastasis in rectal cancer patients (P<0.1). In the training set (120) and the three validation sets (69, 103, 49), the AUC values of the model were much higher than the diagnosis by MR alone (training set, 0.902 vs. 0.580; first validation set, 0.789 vs. 0.743; second validation set, 0.774 vs. 0.573; third validation set, 0.761 vs. 0.524). DATA CONCLUSION:For the diagnosis of metastatic LNs in rectal cancer patients, our proposed logistic regression model, combining clinical and MR data, demonstrated higher diagnostic efficiency than MRI alone. LEVEL OF EVIDENCE:4 TECHNICAL EFFICACY STAGE: 2.
USPIO-enhanced MRI of lymph nodes in rectal cancer: A node-to-node comparison with histopathology.
Stijns Rutger C H,Philips Bart W J,Nagtegaal Iris D,Polat Fatih,de Wilt Johannes H W,Wauters Carla A P,Zamecnik Patrik,Fütterer Jurgen J,Scheenen Tom W J
European journal of radiology
PURPOSE:To evaluate the initial results of predicting lymph node metastasis in rectal cancer patients detected in-vivo with USPIO-enhanced MRI at 3 T compared on a node-to-node basis with histopathology. METHODS:Ten rectal cancer patients of all clinical stages were prospectively included for an in-vivo 0.85 mm isotropic 3D MRI after infusion of Ferumoxtran-10. The surgical specimens were examined ex-vivo with an 0.29 mm isotropic MRI examination. Two radiologists evaluated in-vivo MR images with a classification scheme to predict lymph node status. Ex-vivo MRI was used for MR-guided pathology and served as a key link between in-vivo MRI and final histopathology for the node-to-node analysis. RESULTS:138 lymph nodes were detected by reader 1 and 255 by reader 2 (p = 0.005) on in-vivo MRI with a median size of 2.6 and 2.4 mm, respectively. Lymph nodes were classified with substantial inter-reader agreement (κ = 0.73). Node-to-node comparison was possible for 55 lymph nodes (median size 3.2 mm; range 1.2-12.3), of which 6 were metastatic on pathology. Low true-positive rates (3/26, 11 % for both readers) and high true negative rates were achieved (14/17, 82 %; 19/22, 86 %). Pathological re-evaluations of 20 lymph nodes with high signal intensity on USPIO-enhanced MRI without lymph node metastases (false positives) did not reveal tumor metastasis but showed benign lymph node tissue with reactive follicles. CONCLUSIONS:High resolution MRI visualizes a large number of mesorectal lymph nodes. USPIO-enhanced MRI was not accurate for characterizing small benign versus small tumoral lymph nodes in rectal cancer patients. Suspicious nodes on in-vivo MRI occur as inflammatory as well as metastatic nodes.
Diffusion kurtosis imaging in identifying the malignancy of lymph nodes during the primary staging of rectal cancer.
Yu J,Dai X,Zou H-H,Song J-C,Li Y,Shi H-B,Xu Q,Shen H
Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland
AIM:The aim was to assess the diagnostic value of diffusion kurtosis imaging (DKI) for discriminating between benign and malignant lymph nodes in patients with rectal carcinoma. METHOD:ighty-five patients with rectal adenocarcinoma who underwent total mesorectal excision of the rectum were studied. A total of 273 lymph nodes were harvested and subjected to histological analysis. Quantitative parameters [apparent diffusion parameter D of the Gaussian distribution, apparent kurtosis coefficient K and apparent diffusion coefficient (ADC)] of lymph nodes were derived from DKI. Differences and the diagnostic performance of these parameters were calculated by using the independent-samples t test and receiver operating characteristic curve analyses. RESULTS:The median D and ADC values of metastatic lymph nodes were significantly greater than those of benign lymph nodes, whereas the median K of metastatic lymph nodes was statistically less than that of normal lymph nodes. D had the relatively highest area under the curve of 0.774. When 1126.15 × 10 mm /s was used as a D threshold value, the sensitivity and specificity were 96.97% and 41.82%, respectively. CONCLUSION:DKI can help differentiate metastatic vs benign lymph nodes during the primary staging of rectal cancer.
Apparent diffusion coefficient cannot discriminate metastatic and non-metastatic lymph nodes in rectal cancer: a meta-analysis.
Surov Alexey,Meyer Hans-Jonas,Pech Maciej,Powerski Maciej,Omari Jasan,Wienke Andreas
International journal of colorectal disease
BACKGROUND:Our aim was to provide data regarding use of diffusion-weighted imaging (DWI) for distinguishing metastatic and non-metastatic lymph nodes (LN) in rectal cancer. METHODS:MEDLINE library, EMBASE, and SCOPUS database were screened for associations between DWI and metastatic and non-metastatic LN in rectal cancer up to February 2021. Overall, 9 studies were included into the analysis. Number, mean value, and standard deviation of DWI parameters including apparent diffusion coefficient (ADC) values of metastatic and non-metastatic LN were extracted from the literature. The methodological quality of the studies was investigated according to the QUADAS-2 assessment. The meta-analysis was undertaken by using RevMan 5.3 software. DerSimonian, and Laird random-effects models with inverse-variance weights were used to account the heterogeneity between the studies. Mean DWI values including 95% confidence intervals were calculated for metastatic and non-metastatic LN. RESULTS:ADC values were reported for 1376 LN, 623 (45.3%) metastatic LN, and 754 (54.7%) non-metastatic LN. The calculated mean ADC value (× 10 mm/s) of metastatic LN was 1.05, 95%CI (0.94, 1.15). The calculated mean ADC value of the non-metastatic LN was 1.17, 95%CI (1.01, 1.33). The calculated sensitivity and specificity were 0.81, 95%CI (0.74, 0.89) and 0.67, 95%CI (0.54, 0.79). CONCLUSION:No reliable ADC threshold can be recommended for distinguishing of metastatic and non-metastatic LN in rectal cancer.
Improved detection of a tumorous involvement of the mesorectal fascia and locoregional lymph nodes in locally advanced rectal cancer using DCE-MRI.
Armbruster Marco,D'Anastasi Melvin,Holzner Veronika,Kreis Martin E,Dietrich Olaf,Brandlhuber Bernhard,Graser Anno,Brandlhuber Martina
International journal of colorectal disease
PURPOSE:The prediction of an infiltration of the mesorectal fascia (MRF) and malignant lymph nodes is essential for treatment planning and prognosis of patients with rectal cancer. The aim of this study was to assess the additional diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for the detection of a malignant involvement of the MRF and of mesorectal lymph nodes in patients with locally advanced rectal cancer. METHODS:In this prospective study, 22 patients with locally advanced rectal cancer were examined with 1.5-T MRI between September 2012 and April 2015. Histopathological assessment of tumor size, tumor infiltration to the MRF, and malignant involvement of locoregional lymph nodes served as standard of reference. Sensitivity and specificity of detecting MRF infiltration and malignant nodes (nodal cut-off size [NCO] ≥ 5 and ≥ 10 mm, respectively) was determined by conventional MRI (cMRI; precontrast and postcontrast T1-weighted, T2-weighted, and diffusion-weighted images) and by additional semi-quantitative DCE-MRI maps (cMRI+DCE-MRI). RESULTS:Compared to cMRI, additional semi-quantitative DCE-MRI maps significantly increased sensitivity (86 vs. 71% [NCO ≥ 5 mm]/29% [NCO ≥ 10 mm]) and specificity (90 vs. 70% [NCO ≥ 5 mm]) of detecting malignant lymph nodes (p < 0.05). Moreover, DCE-MRI significantly augmented specificity (91 vs. 82%) of discovering a MRF infiltration (p < 0.05), while there was no change in sensitivity (83%; p > 0.05). CONCLUSION:DCE-MRI considerably increases both sensitivity and specificity for the detection of small mesorectal lymph node metastases (≥ 5 mm but < 10 mm) and sufficiently improves specificity of a suspected MRF infiltration in patients with locally advanced rectal cancer.
Dual-energy CT can detect malignant lymph nodes in rectal cancer.
Al-Najami I,Lahaye M J,Beets-Tan R G H,Baatrup G
European journal of radiology
BACKGROUND:There is a need for an accurate and operator independent method to assess the lymph node status to provide the most optimal personalized treatment for rectal cancer patients. This study evaluates whether Dual Energy Computed Tomography (DECT) could contribute to the preoperative lymph node assessment, and compared it to Magnetic Resonance Imaging (MRI). The objective of this prospective observational feasibility study was to determine the clinical value of the DECT for the detection of metastases in the pelvic lymph nodes of rectal cancer patients and compare the findings to MRI and histopathology. MATERIALS AND METHODS:The patients were referred to total mesorectal excision (TME) without any neoadjuvant oncological treatment. After surgery the rectum specimen was scanned, and lymph nodes were matched to the pathology report. Fifty-four histology proven rectal cancer patients received a pelvic DECT scan and a standard MRI. The Dual Energy CT quantitative parameters were analyzed: Water and Iodine concentration, Dual-Energy Ratio, Dual Energy Index, and Effective Z value, for the benign and malignant lymph node differentiation. RESULTS:DECT scanning showed statistical difference between malignant and benign lymph nodes in the measurements of iodine concentration, Dual-Energy Ratio, Dual Energy Index, and Effective Z value. Dual energy CT classified 42% of the cases correctly according to N-stage compared to 40% for MRI. CONCLUSION:This study showed statistical difference in several quantitative parameters between benign and malignant lymph nodes. There were no difference in the accuracy of lymph node staging between DECT and MRI.
Diagnostic accuracy of endoscopic ultrasound, computed tomography, magnetic resonance imaging, and endorectal ultrasonography for detecting lymph node involvement in patients with rectal cancer: A protocol for an overview of systematic reviews.
Wang Xin,Gao Ya,Li Jipin,Wu Jiarui,Wang Bo,Ma Xueni,Tian Jinhui,Shen Minghui,Wang Jiancheng
BACKGROUND:Rectal cancer is one of the most common tumors and is the leading cause of cancer-related deaths in developed countries. Lymph node involvement remains the strongest prognostic factor associated with a worse prognosis in patients with rectal cancer. Several systematic reviews have investigated the accuracy of endoscopic ultrasound, computed tomography, magnetic resonance imaging, and endorectal ultrasonography for lymph node involvement of rectal cancer and compared the diagnostic accuracy of different imaging techniques, but there are considerable differences in conclusions. This study aims to assess the methodological quality and reporting quality of systematic reviews and to determine which diagnostic imaging techniques is the optimal modality for the diagnosis of lymph node involvement in patients with rectal cancer. METHODS:We will search PubMed, EMBASE, Cochrane Library, and Chinese Biomedicine Literature to identify relevant studies from inception to June 2018. We will include systematic reviews that evaluated the accuracy of diagnostic imaging techniques for lymph node involvement. The methodological quality will be assessed using AMASAR checklist, and the reporting quality will be assessed using PRISMA-DTA checklist. The pairwise meta-analysis and indirect comparisons will be performed using STATA V.12.0. RESULTS:The results of this overview will be submitted to a peer-reviewed journal for publication. CONCLUSION:This overview will provide comprehensive evidence of different diagnostic imaging techniques for detecting lymph node involvement in patients with rectal cancer. ETHICS AND DISSEMINATION:Ethics approval and patient consent are not required as this study is an overview based on published systematic reviews. PROSPERO REGISTRATION NUMBER:CRD42018104906.
The value of four imaging modalities in diagnosing lymph node involvement in rectal cancer: an overview and adjusted indirect comparison.
Gao Ya,Li Jipin,Ma Xueni,Wang Jiancheng,Wang Bo,Tian Jinhui,Chen Gen
Clinical and experimental medicine
Several systematic reviews have investigated the accuracy of imaging modalities for lymph node involvement of rectal cancer, but there are considerable differences in conclusions. This overview aimed to assess the methodological and reporting quality of systematic reviews that evaluated the diagnostic value of imaging modalities for lymph node involvement in patients with rectal cancer and to compare the diagnostic value of different modalities for lymph node involvement. The PubMed, EMBASE, Cochrane Library and Chinese Biomedicine Literature were searched to identify relevant systematic reviews. The methodological quality was assessed using the AMSTAR checklist, and the reporting quality was assessed using PRISMA-DTA checklist. The indirect comparison was conducted to compare the accuracy of different imaging modalities. Seven systematic reviews involving 353 primary studies were included. The median (Range) AMSTAR scores were 6.0 (4.0-9.0); the median (Range) PRISMA-DTA scores were 18.0 (11.0-23.0). Sensitivity of MRI [0.69 (95% CI 0.63, 0.77)] was significantly higher than that of ERUS [0.57 (95% CI 0.53, 0.62)]. Specificity of ERUS [0.80 (95% CI 0.77, 0.83)] was significantly higher than that of CT [0.72 (95% CI 0.67, 0.78)]. Positive likelihood ratio of EUS [3.04 (95% CI 2.75, 3.36)] was significantly higher than that of CT [2.21 (95% CI 1.69, 2.90)]. EUS had better diagnostic value than CT and ERUS in the diagnosis of lymph node involvement. Compared with CT and ERUS, MRI was more sensitive. EUS and MRI had comparable diagnostic accuracy, but no modality was proved to be particularly accurate.
Diagnostic accuracy of magnetic resonance imaging and computed tomography for lateral lymph node metastasis in rectal cancer: a systematic review and meta-analysis.
Hoshino Nobuaki,Murakami Katsuhiro,Hida Koya,Sakamoto Takashi,Sakai Yoshiharu
International journal of clinical oncology
PURPOSE:Accurate diagnosis of lateral lymph node metastasis is a major concern in rectal cancer. Metastasis is not only a poor prognostic factor, but it can also affect decisions about treatment options, such as preoperative chemoradiotherapy and lateral lymph node dissection. The purpose of this review was to assess the diagnostic performance of magnetic resonance imaging and computed tomography for lateral lymph node metastasis in rectal cancer. METHODS:A literature search was systematically performed using PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. All studies in which preoperative magnetic resonance imaging or computed tomography findings involving the lateral lymph nodes were compared with pathologic findings were included. Two authors independently assessed the literature and extracted the data, and any disagreement was resolved by discussion. Pooled sensitivity, specificity, and diagnostic odds ratios were estimated using hierarchical summary receiver-operating characteristic curve analysis. The methodologic quality of the included studies was assessed using the QUADAS-2 tool. RESULTS:Nine studies were included in the meta-analysis of magnetic resonance imaging. The pooled sensitivity, specificity, and diagnostic odds ratio for magnetic resonance imaging were 0.72 [95% confidence interval (CI) 0.66-0.78], 0.80 (95% CI 0.73-0.85), and 10.2 (95% CI 6.4-16.3), respectively. Pooled analyses were not conducted for computed tomography because of the small number of studies (only three could be identified) and the wide range in diagnostic performance between these studies. CONCLUSIONS:Magnetic resonance imaging was useful to diagnose lateral lymph node metastasis in rectal cancer, especially due to high specificity.
Value of MRI morphologic features with pT1-2 rectal cancer in determining lymph node metastasis.
Tang Yibo,Rao Shengxiang,Yang Chun,Hu Yabin,Sheng Ruofan,Zeng Mengsu
Journal of surgical oncology
BACKGROUND AND OBJECTIVES:To investigate the different features between metastatic lymph node and nonmetastatic lymph node on magnetic resonance imaging (MRI) and the relationship between the rectal lesion and lymph node metastasis (LNM). METHODS:Eighty-two patients with retrospectively consecutive pT1-2 stage rectal cancer in 2016 were divided into lymph node metastasis (LNM+) and lymph node nonmetastasis (LNM-) group based on their histopathologic examinations. We evaluated the following features of lymph nodes: number, shape, signal heterogeneity, border, and diameter of the largest lymph node on T2-weight images. We also calculated tumor apparent diffusion coefficient ratio and tumor percent enhancement. Fisher's exact test was applied for inspecting lymph node numbers on MRI and logistic regression analysis in examining risk factors for LNM. RESULTS:The MR-LN number was significantly different between the LNM+ and LNM- group (median: 4 vs 1, P = 0.001). Multivariate logistic regression analysis exhibited that the diameter of the largest lymph node and the tumor percent enhancement of the arterial phase were independent risk factors of LNM (P = 0.005 vs 0.021, respectively). CONCLUSIONS:The largest lymph node's diameter and the tumor percent enhancement of arterial phase on MRI were helpful in determining LNM in pT1-2 rectal cancer.
MRI Lymph Node Evaluation for Prediction of Metastases in Rectal Cancer.
Almlöv Karin,Woisetschläger Mischa,Loftås Per,Hallböök Olof,Elander Nils O,Sandström Per
AIM:To explore whether the size and characteristics of the largest regional lymph node in patients with rectal cancer, based on magnetic resonance imaging (MRI), following neoadjuvant therapy and before surgery, is able to identify patients at high risk of developing metachronous metastases. PATIENTS AND METHODS:A retrospective case-control study with data from the Swedish Colo-Rectal Cancer Registry. Forty patients were identified with metachronous metastases (M+), and 40 patients without metastases (M0) were matched as controls. RESULTS:Patients with M+ disease were more likely to have a regional lymph node measuring ≥5 mm than patients with M0. (87% vs. 65%, p=0.02). There was also a significant difference between the groups regarding the presence of an irregular border of the largest lymph node (68% vs. 40%, p=0.01). CONCLUSION:Lymph nodes measuring ≥5 mm with/without displaying irregular borders at MRI performed after neoadjuvant therapy emerged as risk factors for metachronous metastases in patients with rectal cancer. Intensified follow-up programmes may be indicated in these patients.
Metastatic lymph node calcification in rectal cancer: comparison of CT and high-resolution MRI.
Chen Yan,Wen Ziqiang,Ma Yuru,Liu Yiyan,Que Yutao,Yang Xinyue,Wu Yunzhu,Yu Shenping
Japanese journal of radiology
Calcification causes mixed signal intensity in the lymph node (LN) on high-resolution magnetic resonance imaging (MRI), which is a strong indicator of regional LN metastasis in rectal cancer. Calcified metastatic LNs in rectal cancer commonly display scattered fine punctate calcifications to varying degrees on computed tomography (CT). On high-resolution MRI, the calcifications manifest a patchy area of signal loss in corresponding calcified area that is larger than on CT. It is necessary to recognize the appearance of metastatic LN calcifications on high-resolution MRI in rectal cancer because it is the primary imaging method for local staging in rectal cancer. This pictorial essay aims to introduce an important imaging finding that can contribute to the diagnosis of LN metastasis by illustrating features and differences between CT and high-resolution MRI of metastatic LN calcifications in rectal cancer.
Higher-order diffusion MRI characterization of mesorectal lymph nodes in rectal cancer.
Ianuş Andrada,Santiago Ines,Galzerano Antonio,Montesinos Paula,Loução Nuno,Sanchez-Gonzalez Javier,Alexander Daniel C,Matos Celso,Shemesh Noam
Magnetic resonance in medicine
PURPOSE:Mesorectal lymph node staging plays an important role in treatment decision making. Here, we explore the benefit of higher-order diffusion MRI models accounting for non-Gaussian diffusion effects to classify mesorectal lymph nodes both 1) ex vivo at ultrahigh field correlated with histology and 2) in vivo in a clinical scanner upon patient staging. METHODS:The preclinical investigation included 54 mesorectal lymph nodes, which were scanned at 16.4 T with an extensive diffusion MRI acquisition. Eight diffusion models were compared in terms of goodness of fit, lymph node classification ability, and histology correlation. In the clinical part of this study, 10 rectal cancer patients were scanned with diffusion MRI at 1.5 T, and 72 lymph nodes were analyzed with Apparent Diffusion Coefficient (ADC), Intravoxel Incoherent Motion (IVIM), Kurtosis, and IVIM-Kurtosis. RESULTS:Compartment models including restricted and anisotropic diffusion improved the preclinical data fit, as well as the lymph node classification, compared to standard ADC. The comparison with histology revealed only moderate correlations, and the highest values were observed between diffusion anisotropy metrics and cell area fraction. In the clinical study, the diffusivity from IVIM-Kurtosis was the only metric showing significant differences between benign (0.80 ± 0.30 μm /ms) and malignant (1.02 ± 0.41 μm /ms, P = .03) nodes. IVIM-Kurtosis also yielded the largest area under the receiver operating characteristic curve (0.73) and significantly improved the node differentiation when added to the standard visual analysis by experts based on T -weighted imaging. CONCLUSION:Higher-order diffusion MRI models perform better than standard ADC and may be of added value for mesorectal lymph node classification in rectal cancer patients.
Value of High-resolution MRI in Detecting Lymph Node Calcifications in Patients with Rectal Cancer.
Chen Yan,Wen Ziqiang,Liu Yiyan,Yang Xinyue,Ma Yuru,Lu Baolan,Xiao Xiaojuan,Yu Shenping
RATIONALE AND OBJECTIVES:To analyze CT and high-resolution MRI findings of nodal metastasis calcifications and determine the value of high-resolution MRI in detecting nodal calcifications in rectal cancer patients. MATERIALS AND METHODS:In total, 229 rectal cancer patients were included. The CT was reviewed for the presence of nodal calcifications by two radiologists. High-resolution two-dimensional turbo spin-echo T2-weighted imaging (2D-TSE-T2WI) and fat-suppressed gadolinium-enhanced isotropic high-resolution three-dimensional gradient-echo T1-weighted imaging (3D-GRE-T1WI) were independently reviewed for nodal calcifications by the two radiologists at one-month and two-month intervals, respectively. The sensitivities, specificities and accuracies of the two high-resolution MRI in detecting nodal calcifications were calculated using CT results as a reference. RESULTS:Regional calcified metastatic lymph nodes were found in 28 patients. The node-to-node evaluation revealed that 55 (98.2%) of the 56 calcified lymph nodes were metastatic. Fifty-one (92.7%) calcified metastatic lymph nodes displayed scattered fine punctate calcifications to different degrees on CT. In both types of high-resolution MRI, the calcifications demonstrated a patchy area of markedly reduced signal intensity in corresponding areas that were larger than those on CT. The sensitivity and accuracy of fat-suppressed gadolinium-enhanced isotropic high-resolution 3D-GRE-T1WI were significantly higher than those of high-resolution 2D-TSE-T2WI (76.8% vs 58.9%, P = 0.013; 98.3% vs 97.9%, P = 0.007; respectively). CONCLUSION:Metastatic nodal calcifications are characteristic imaging findings in rectal cancer. Calcifications are indicated by markedly reduced signal on high-resolution MRI, which will alert radiologists to scrutinize CT for nodal calcifications and aid in the accurate diagnosis of metastatic lymph nodes.
[MRI associated biomarker analysis for diagnosis of lymph node metastasis in T1-2 stage rectal cancer].
Liu Y,Wan L J,Zhang H M,Peng W J,Zou S M,Ouyang H,Zhao X M,Zhou C W
Zhonghua zhong liu za zhi [Chinese journal of oncology]
To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment. Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors. Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis (<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology (=0.002), including mucus or not (<0.001), and MR-N evaluation (<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95% 0.720~0.852). Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.
Diagnosis of lymph node metastasis on rectal cancer by PET-CT computer imaging combined with MRI technology.
Li Fangwei,Hu Jiahang,Jiang Hua,Sun Yan
Journal of infection and public health
To compare the diagnostic efficacy and clinical application value of Positron Emission Tomography-Computed Tomography (PET-CT) metabolic computer Imaging imaging and Magnetic Resonance Imaging (MRI) diffusion imaging technology for regional lymph node metastasis in rectal cancer, 41 patients with rectal cancer confirmed by colonoscopy were collected and underwent 3.0T pelvic MRI and PET-CT examination, respectively. PET-CT/MRI fusion software was used to fuse magnetic resonance images and PET-CT images and accurately locate the rectal cancer lesions and lymph nodes, and image-operation-pathology control method was used to identify the lymph nodes around the rectum. In addition, independent sample t-test or Mann-Whitney U test were used to compare the differences in the values of various parameters between the two groups of metastatic lymph nodes and non-metastatic lymph nodes, Spearman correlation was used to analyze the correlation between SUV value and ADC value of metastatic lymph node, and the diagnostic value of SUV value and ADC value was evaluated by drawing ROC curve. The results showed that when SUV took 2.0 as the diagnostic threshold, the accuracy of PET-CT in diagnosing metastatic lymph nodes was 90.1%; when the diagnostic threshold of ADC was 1.0×10mm/s, the accuracy of DWI in diagnosing metastatic lymph nodes was 84.2%; the accuracy of the combination of the two methods for the diagnosis of metastatic lymph nodes was 94.4%. Therefore, it can be concluded that both PET-CT and MRI diffusion images were of high diagnostic value in the diagnosis of lymph node metastasis of rectal cancer, and their diagnostic results were highly consistent. When combined, the diagnostic accuracy can be further improved.
Inguinal lymph node metastases are recognized with high frequency in rectal adenocarcinoma invading the dentate line. The histological features at the invasive front may predict inguinal lymph node metastasis.
Hamano T,Homma Y,Otsuki Y,Shimizu S,Kobayashi H,Kobayashi Y
Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland
AIM:Inguinal lymph node (ILN) metastasis occurs with high frequency in some of the patients with lower rectal cancer. The aim of this study was to identify risk factors for ILN metastasis in patients with low rectal adenocarcinoma. METHOD:We retrospectively analysed 156 patients with lower rectal adenocarcinoma who underwent radical resection (R0) at a single institution. RESULTS:Twenty-five (16%) patients had a tumour that invaded the dentate line, seven of whom had ILN metastasis. Invasion of the dentate line was significantly associated with a high rate of ILN metastasis, worse prognosis and local recurrence than with a tumour not invading the dentate line (P = 0.03). A Cox proportional hazard regression analysis revealed the histological characteristics at the invading front (Hif) also to be a risk factor for ILN metastasis. CONCLUSION:Tumours which invade the dentate line have a high rate of ILN metastases and worse cancer specific end-points. The presence of poorly differentiated or mucinous adenocarcinoma components is an indication for bilateral groin irradiation.
[Diagnostic accuracy of 3.0T high-resolution MRI for assessment mesorectal lymph node metastases in patients with rectal cancer].
Chen Yan,Yang Xinyue,Lu Baolan,Xiao Xiaojuan,Zhuang Xiaozhao,Yu Shenping
Zhonghua wei chang wai ke za zhi = Chinese journal of gastrointestinal surgery
OBJECTIVE:To evaluate the diagnostic value of 3.0T high-resolution MRI in mesorectal lymph node metastasis of rectal cancer. METHODS:The images and postoperative pathological data of patients with pathologically diagnosed rectal cancer who underwent prospective 3.0T two dimensional high-resolution MRI rectal examinations and surgery within two weeks after MRI examination at the First Affiliated Hospital, Sun Yat-sen University from November 2015 to November 2016 were retrospectively collected. Patients who received preoperative neoadjuvant therapy and those who did not undergo operation after MRI examination were excluded. The MRI sequences included high-resolution sagittal, coronal and oblique axial T2 weighted image (T2WI) (repetition time/echo time, 3000-4000 ms/77-87 ms; slice thickness/gap, 3 mm/0 mm; field of view, 18-22 cm). Two abdominal MRI radiologists independently assessed the morphology, margin, signal of all visible mesorectal nodes, measured their minor axes (three times for each radiologist) and gave estimation of the malignancy. The criteria of metastatic nodes on high-resolution MRI T2WI were nodes with irregular shape, ill-defined border and/or heterogeneous signal. The results of MRI diagnosis were compared with postoperative pathology. The sensitivity, specificity, accuracy, positive predictive value(PPV) and negative predictive value(NPV) of mesorectal nodes and nodes with different short-axis diameter ranges were calculated to evaluate the diagnostic efficiency of high-resolution MRI. Kappa statistics was used to evaluate the agreement for per node and for per patient between high-resolution MRI and pathological results. A Kappa value of 0-0.20 indicated poor agreement; 0.21-0.40 fair agreement; 0.41-0.60 moderate agreement; 0.61-0.80 good agreement; and 0.81-1.00 excellent agreement. RESULTS:A total of 81 patients were enrolled in the retrospective cohort study, including 50 males and 31 females with age of (59.3±11.1) years. Histopathology showed 1 case of well differentiated adenocarcinoma, 63 of moderately differentiated adenocarcinoma, 9 of moderately to poorly differentiated adenocarcinoma, 2 of poorly differentiated adenocarcinoma, 3 of mucinous adenocarcinoma and 3 of tubulovillous adenocarcinoma. Histopathological staging showed 2 cases in T1 stage, 20 in T2 stage, 45 in T3 stage and 14 in T4 stage; 34 in N0 stage, 40 in N1 stage and 7 in N2 stage; 76 in M0 stage and 5 in M1 stage. A total of 377 nodes were included in the node-by-node evaluation, of which 168 (44.6%) nodes were metastatic from 58.0% (47/81) patients. The median short-axis diameter was 5.4(2.4-18.6) mm in metastatic nodes, which was significantly larger than 3.8 (2.0-8.7) mm in non-metastatic nodes[Z=10.586, P=0.000]. The sensitivity, specificity, accuracy, PPV and NPV were 74.4% (125/168), 94.7% (198/209), 85.7% (323/377), 91.9% (125/136) and 82.2% (198/241), respectively. The Kappa values between high-resolution MRI and histopathological diagnosis for node-by-node and patient-by-patient were 0.71 and 0.70 respectively, indicating good agreements. Fourteen nodes >10 mm were all metastatic. The results of high-resolution MRI for nodal status were consistent with the results of histopathological diagnosis, and the sensitivity, accuracy and PPV were all 100.0%. Among 124 nodes with short-axis diameter of 5-10 mm, 95 (76.6%) were metastatic, and the sensitivity, specificity, accuracy, PPV and NPV were 78.9% (75/95), 86.2% (25/29), 80.6% (100/124), 94.9% (75/79) and 55.6% (25/45), respectively. The agreement was fair (Kappa value 0.55) between high-resolution MRI and histopathological diagnosis. Among 239 nodes with short-axis diameter ≤5 mm, 59(24.7%) were metastatic, and the sensitivity, specificity, accuracy, PPV and NPV were 61.0% (36/59), 96.1%(173/180), 87.4%(209/239), 83.7%(36/43) and 88.3%(173/196), respectively. The agreement was good (Kappa value 0.63) between high-resolution MRI and histopathological diagnosis. CONCLUSION:Rectal high-resolution MRI has good diagnostic value for estimating metastatic mesorectal nodes by evaluating the morphology, margin and signal of nodes.
Feasibility and reproducibility of T2 mapping and DWI for identifying malignant lymph nodes in rectal cancer.
Ge Yu-Xi,Hu Shu-Dong,Wang Zi,Guan Rong-Ping,Zhou Xin-Yi,Gao Qi-Zhong,Yan Gen
OBJECTIVES:To evaluate the diagnostic value and reproducibility of T2 mapping versus apparent diffusion coefficients (ADC) for identifying malignant lymph nodes in patients with non-mucinous rectal adenocarcinoma. METHODS:High-resolution magnetic resonance imaging, diffusion-weighted imaging, and T2 mapping were performed on patients with suspected metastatic lymph nodes in the mesorectum or around the superior rectal artery with a short-axis diameter of 4-10 mm. The T2 and ADC values of pathology-confirmed metastatic versus non-metastatic lymph nodes were compared using the independent-samples t test and receiver operating characteristic curves. Intra- and inter-observer reproducibility were tested. The cutoff value for T2 relaxation time was determined. RESULTS:In total, 67 lymph nodes underwent histological analysis, with 24 in the non-metastatic and 43 in the metastatic groups. Intra- and inter-observer agreements for T2 values were 0.999 and 0.998, respectively, which were higher than the ADC values of 0.924 and 0.844, respectively. The mean T2 and ADC values for metastatic lymph nodes (65 ± 7.8 ms and 1.17 ± 0.16 × 10 mm/s, respectively) were significantly lower than for benign lymph nodes(83 ± 5.7 ms and 1.29 ± 0.15 × 10 mm/s, respectively). T2 values had a higher AUC value of 0.990 than the AUC value for ADC of 0.729. With a cutoff value of 77 ms, sensitivity and specificity for T2 values were 95% and 96%, respectively. CONCLUSIONS:T2 mapping had higher diagnostic efficacy and reproducibility than ADC and may be useful in differentiating metastatic from non-metastatic lymph nodes in rectal cancer. KEY POINTS:• Mean T2 values were significantly shorter for malignant versus benign LNs in patients with non-mucinous rectal adenocarcinoma. • The diagnostic efficacy and reproducibility of T2 values were excellent and superior to ADC values.
A radiomics approach based on support vector machine using MR images for preoperative lymph node status evaluation in intrahepatic cholangiocarcinoma.
Xu Lei,Yang Pengfei,Liang Wenjie,Liu Weihai,Wang Weigen,Luo Chen,Wang Jing,Peng Zhiyi,Xing Lei,Huang Mi,Zheng Shusen,Niu Tianye
: Accurate lymph node (LN) status evaluation for intrahepatic cholangiocarcinoma (ICC) patients is essential for surgical planning. This study aimed to develop and validate a prediction model for preoperative LN status evaluation in ICC patients. : A group of 106 ICC patients, who were diagnosed between April 2011 and February 2016, was used for prediction model training. Image features were extracted from T1-weighted contrast-enhanced MR images. A support vector machine (SVM) model was built by using the most LN status-related features, which were selected using the maximum relevance minimum redundancy (mRMR) algorithm. The mRMR method ranked each feature according to its relevance to the LN status and redundancy with other features. An SVM score was calculated for each patient to reflect the LN metastasis (LNM) probability from the SVM model. Finally, a combination nomogram was constructed by incorporating the SVM score and clinical features. An independent group of 42 patients who were diagnosed from March 2016 to November 2017 was used to validate the prediction models. The model performances were evaluated on discrimination, calibration, and clinical utility. : The SVM model was constructed based on five selected image features. Significant differences were found between patients with LNM and non-LNM in SVM scores in both groups (the training group: 0.5466 (interquartile range (IQR), 0.4059-0.6985) vs. 0.3226 (IQR, 0.0527-0.4659), <0.0001; the validation group: 0.5831 (IQR, 0.3641-0.8162) vs. 0.3101 (IQR, 0.1029-0.4661), =0.0015). The combination nomogram based on the SVM score, the CA 19-9 level, and the MR-reported LNM factor showed better discrimination in separating patients with LNM and non-LNM, comparing to the SVM model alone (AUC: the training group: 0.842 vs. 0.788; the validation group: 0.870 vs. 0.787). Favorable clinical utility was observed using the decision curve analysis for the nomogram. : The nomogram, incorporating the SVM score, CA 19-9 level and the MR-reported LNM factor, provided an individualized LN status evaluation and helped clinicians guide the surgical decisions.
Lateral Nodal Features on Restaging Magnetic Resonance Imaging Associated With Lateral Local Recurrence in Low Rectal Cancer After Neoadjuvant Chemoradiotherapy or Radiotherapy.
Ogura Atsushi,Konishi Tsuyoshi,Beets Geerard L,Cunningham Chris,Garcia-Aguilar Julio,Iversen Henrik,Toda Shigeo,Lee In Kyu,Lee Hong Xiang,Uehara Keisuke,Lee Peter,Putter Hein,van de Velde Cornelis J H,Rutten Harm J T,Tuynman Jurriaan B,Kusters Miranda,
Importance:Previously, it was shown in patients with low rectal cancer that a short-axis (SA) lateral node size of 7 mm or greater on primary magnetic resonance imaging (MRI) resulted in a high lateral local recurrence (LLR) rate after chemoradiotherapy or radiotherapy ([C]RT) with total mesorectal excision (TME) and that this risk was lowered by a lateral lymph node dissection (LLND). The role of restaging MRI after (C)RT with regard to LLR risk and which specific patients might benefit from an LLND is not fully understood. Objective:To determine the factors on primary and restaging MRI that are associated with LLR in low rectal cancer after (C)RT and to formulate specific guidelines on which patients might benefit from an LLND. Design, Setting, and Participants:In this retrospective, multicenter, pooled cohort study, patients who underwent surgery for cT3 or cT4 low rectal cancer with a curative intent from 12 centers in 7 countries from January 2009 to December 2013 were included. All patients' MRIs were rereviewed according to a standardized protocol, with specific attention to lateral nodal features. The original cohort included 1216 patients. For this study, patients who underwent (C)RT and had a restaging MRI were selected, leaving 741 for analyses across 10 institutions, including 651 who underwent (C)RT with TME and 90 who underwent (C)RT with TME and LLND. Main Outcomes and Measures:The main purpose was to identify the factors on primary and restaging MRI associated with LLR after (C)RT with TME. Whether high-risk patients might benefit in terms of LLR reduction from an LLND was also studied. Results:Of the 741 included patients, 480 (64.8%) were male, and the mean (SD) age was 60.4 (12.0) years. An SA lateral node size of 7 mm or greater on primary MRI resulted in a 5-year LLR rate of 17.9% after (C)RT with TME. At 3 years, there were no LLRs in 28 patients (29.2%) with lateral nodes that were 4 mm or less on restaging MRI. Nodes that were 7 mm or greater on primary MRI and greater than 4 mm on restaging MRI in the internal iliac compartment resulted in a 5-year LLR rate of 52.3%, significantly higher compared with nodes in the obturator compartment of that size (9.5%; hazard ratio, 5.8; 95% CI, 1.6-21.3; P = .003). Compared with (C)RT with TME alone, treatment with (C)RT with TME and LLND in these unresponsive internal nodes resulted in a significantly lower LLR rate of 8.7% (hazard ratio, 6.2; 95% CI, 1.4-28.5; P = .007). Conclusions and Relevance:Restaging MRI is important in clinical decision making in lateral nodal disease. In patients with shrinkage of lateral nodes from an SA node size of 7 mm or greater on primary MRI to an SA node size of 4 mm or less on restaging MRI, which occurs in about 30% of cases, LLND can be avoided. However, persistently enlarged nodes in the internal iliac compartment indicate an extremely high risk of LLR, and an LLND lowered LLR in these cases.
Susceptibility Perturbation MRI Maps Tumor Infiltration into Mesorectal Lymph Nodes.
Santiago Inês,Santinha João,Ianus Andrada,Galzerano Antonio,Theias Rita,Maia Joana,Barata Maria J,Loução Nuno,Costa-Silva Bruno,Beltran Antonio,Matos Celso,Shemesh Noam
Noninvasive characterization of lymph node involvement in cancer is an enduring onerous challenge. In rectal cancer, pathologic lymph node status constitutes the most important determinant of local recurrence and overall survival, and patients with involved lymph nodes may benefit from preoperative chemo and/or radiotherapy. However, knowledge of lymph node status before surgery is currently hampered by limited imaging accuracy. Here, we introduce Susceptibility-Perturbation MRI (SPI) as a novel source of contrast to map malignant infiltration into mesorectal lymph nodes. SPI involves multigradient echo (MGE) signal decays presenting a nonmonoexponential nature, which we show is sensitive to the underlying microstructure via susceptibility perturbations. Using numerical simulations, we predicted that the large cell morphology and the high cellularity of tumor within affected mesorectal lymph nodes would induce signature SPI decays. We validated this prediction in mesorectal lymph nodes excised from total mesorectal excision specimens of patients with rectal cancer using ultrahigh field (16.4 T) MRI. SPI signals distinguished benign from malignant nodal tissue, both qualitatively and quantitatively, and our histologic analyses confirmed cellularity and cell size were the likely underlying sources for the differences observed. SPI was then adapted to a clinical 1.5 T scanner, added to patients' staging protocol, and compared with conventional assessment by two expert radiologists. Nonmonoexponential decays, similar to those observed in the study, were demonstrated, and SPI classified lymph nodes more accurately than standard high-resolution T-weighted imaging assessment. These findings suggest this simple, yet highly informative, method can improve rectal cancer patient selection for neoadjuvant therapy. SIGNIFICANCE: These findings introduce an MRI methodology tailored to detect magnetic susceptibility perturbations induced by subtle alterations in tissue microstructure.
Neoadjuvant (Chemo)radiotherapy With Total Mesorectal Excision Only Is Not Sufficient to Prevent Lateral Local Recurrence in Enlarged Nodes: Results of the Multicenter Lateral Node Study of Patients With Low cT3/4 Rectal Cancer.
Ogura Atsushi,Konishi Tsuyoshi,Cunningham Chris,Garcia-Aguilar Julio,Iversen Henrik,Toda Shigeo,Lee In Kyu,Lee Hong Xiang,Uehara Keisuke,Lee Peter,Putter Hein,van de Velde Cornelis J H,Beets Geerard L,Rutten Harm J T,Kusters Miranda,
Journal of clinical oncology : official journal of the American Society of Clinical Oncology
PURPOSE:Improvements in magnetic resonance imaging (MRI), total mesorectal excision (TME) surgery, and the use of (chemo)radiotherapy ([C]RT) have improved local control of rectal cancer; however, we have been unable to eradicate local recurrence (LR). Even in the face of TME and negative resection margins (R0), a significant proportion of patients with enlarged lateral lymph nodes (LLNs) suffer from lateral LR (LLR). Japanese studies suggest that the addition of an LLN dissection (LLND) could reduce LLR. This multicenter pooled analysis aims to ascertain whether LLNs actually pose a problem and whether LLND results in fewer LLRs. PATIENTS AND METHODS:Data from 1,216 consecutive patients with cT3/T4 rectal cancers up to 8 cm from the anal verge who underwent surgery in a 5-year period were collected. LLND was performed in 142 patients (12%). MRIs were re-evaluated with a standardized protocol to assess LLN features. RESULTS:On pretreatment MRI, 703 patients (58%) had visible LLN, and 192 (16%) had a short axis of at least 7 mm. One hundred eight patients developed LR (5-year LR rate, 10.0%), of which 59 (54%) were LLRs (5-year LLR rate, 5.5%). After multivariable analyses, LLNs with a short axis of at least 7 mm resulted in a significantly higher risk of LLR (hazard ratio, 2.060; P = .045) compared with LLNs of less than 7 mm. In patients with LLNs at least 7 mm, (C)RT plus TME plus LLND resulted in a 5-year LLR of 5.7%, which was significantly lower than that in patients who underwent (C)RT plus TME (5-year LLR, 19.5%; P = .042). CONCLUSION:LLR is still a significant problem after (C)RT plus TME in LLNs with a short axis at least 7 mm on pretreatment MRI. The addition of LLND results in a significantly lower LLR rate.
Rectal cancer: can T2WI histogram of the primary tumor help predict the existence of lymph node metastasis?
Yang Lanqing,Liu Dan,Fang Xin,Wang Ziqiang,Xing Yue,Ma Ling,Wu Bing
OBJECTIVES:To explore if there is a correlation between T2WI histogram features of the primary tumor and the existence of regional lymph node (LN) metastasis in rectal cancer. METHODS:Eighty-eight patients with pathologically proven rectal adenocarcinoma, who received direct surgical resection and underwent preoperative rectal MRIs, were enrolled retrospectively. Based on pathological analysis of surgical specimen, patients were classified into negative LN (LN-) and positive LN (LN+) groups. The degree of differentiation and pathological T stage were recorded. Clinical T stage, tumor location, and maximum diameter of tumor were evaluated of each patient. Whole-tumor texture analysis was independently performed by two radiologists on axial T2WI, including skewness, kurtosis, energy, and entropy. RESULTS:The interobserver agreement was overall good for texture analysis between two radiologists, with intraclass correlation coefficients (ICCs) ranging from 0.626 to 0.826. The LN- group had a significantly higher skewness (p < 0.001), kurtosis (p < 0.001), and energy (p = 0.004) than the LN+ group, and a lower entropy (p = 0.028). These four parameters showed moderate to good diagnostic power in predicting LN metastasis with respective AUC of 0.750, 0.733, 0.669, and 0.648. In addition, they were both correlated with LN metastasis (r = - 0.413, - 0.385, - 0.28, and 0.245, respectively). The multivariate analysis showed that lower skewness was an independent risk factor of LN metastasis (odds ratio, OR = 9.832; 95%CI, 1.171-56.295; p = 0.01). CONCLUSIONS:Signal intensity histogram parameters of primary tumor on T2WI were associated with regional LN status in rectal cancer, which may help improve the prediction of nodal stage. KEY POINTS:• Histogram parameters of tumor on T2WI may help to reduce uncertainty when assessing LN status in rectal cancer. • Histogram parameters of tumor on T2WI showed a significant difference between different regional LN status groups in rectal cancer. • Skewness was an independent risk factor of regional LN metastasis in rectal cancer.
Identification of Metastatic Lymph Nodes in MR Imaging with Faster Region-Based Convolutional Neural Networks.
Lu Yun,Yu Qiyue,Gao Yuanxiang,Zhou Yunpeng,Liu Guangwei,Dong Qian,Ma Jinlong,Ding Lei,Yao Hongwei,Zhang Zhongtao,Xiao Gang,An Qi,Wang Guiying,Xi Jinchuan,Yuan Weitang,Lian Yugui,Zhang Dianliang,Zhao Chunbo,Yao Qin,Liu Wei,Zhou Xiaoming,Liu Shuhao,Wu Qingyao,Xu Wenjian,Zhang Jianli,Wang Dongshen,Sun Zhenqing,Gao Yuan,Zhang Xianxiang,Hu Jilin,Zhang Maoshen,Wang Guanrong,Zheng Xuefeng,Wang Lei,Zhao Jie,Yang Shujian
MRI is the gold standard for confirming a pelvic lymph node metastasis diagnosis. Traditionally, medical radiologists have analyzed MRI image features of regional lymph nodes to make diagnostic decisions based on their subjective experience; this diagnosis lacks objectivity and accuracy. This study trained a faster region-based convolutional neural network (Faster R-CNN) with 28,080 MRI images of lymph node metastasis, allowing the Faster R-CNN to read those images and to make diagnoses. For clinical verification, 414 cases of rectal cancer at various medical centers were collected, and Faster R-CNN-based diagnoses were compared with radiologist diagnoses using receiver operating characteristic curves (ROC). The area under the Faster R-CNN ROC was 0.912, indicating a more effective and objective diagnosis. The Faster R-CNN diagnosis time was 20 s/case, which was much shorter than the average time (600 s/case) of the radiologist diagnoses. Faster R-CNN enables accurate and efficient diagnosis of lymph node metastases. .
Value of 3Tesla MRI in the preoperative staging of mid-low rectal cancer and its impact on clinical strategies.
Xu Liping,Zhang Chi,Zhang Zhaoyue,Qin Qin,Sun Xinchen
Asia-Pacific journal of clinical oncology
BACKGROUND:To determine the diagnostic accuracy of preoperative T/N stage with magnetic resonance imaging (MRI) in lower and middle rectal cancer patients and the impacts on clinical decision-making. PATIENTS AND METHODS:A total of 211 patients were recruited from October 2015 to March 2017 in this retrospective study. High-resolution MRI was performed within 2 weeks before surgery. Histopathologic results were evaluated for the postoperative T/N stage and the diagnostic accuracy of MRI was assessed according to the postoperative histopathologic results. The accuracy, sensitivity, specificity, positive predictive value and negative predictive value were evaluated for T/N staging and κ values were used to evaluate MRI consistent analysis compared with postoperative histopathologic staging. RESULTS:The overall MRI diagnostic accuracy was 79.62% for T1-4 staging and 54.50% for N0-2 staging. The κ values were 0.619 and 0.255 for T1-4 and N0-2 staging, respectively. The diagnostic accuracy of MRI for treatment decision-making was 80.57%. CONCLUSION:MRI allows a highly accurate preoperative assessment of T stage but only a fairly accurate preoperative assessment of N stage for rectal cancer. The diagnostic accuracy of MRI for treatment decision-making is promising, but additional studies are needed to validate these findings in a larger sample size from multiple centers.
Lymph Node Positivity in T1/T2 Rectal Cancer: a Word of Caution in an Era of Increased Incidence and Changing Biology for Rectal Cancer.
Fields Adam C,Lu Pamela,Hu Frances,Hirji Sameer,Irani Jennifer,Bleday Ronald,Melnitchouk Nelya,Goldberg Joel E
Journal of gastrointestinal surgery : official journal of the Society for Surgery of the Alimentary Tract
BACKGROUND:The evaluation of lymph nodes in rectal cancer dictates treatment. The goals of this study are to characterize the contemporary rate of lymph node metastasis in early stage rectal cancer and to re-investigate histologic factors that predict positive lymph nodes. MATERIALS AND METHODS:Using the National Cancer Database, we identified patients with clinical stage I rectal adenocarcinoma. Multivariable logistic regression was used to determine risk factors for lymph node positivity. RESULTS:12.2% of patients with T1 tumors and 18.0% of patients with T2 tumors had positive lymph nodes. For T1 tumors, positive lymph nodes were present in 9.3% with neither poor differentiation nor lymphovascular invasion (LVI), 17.3% with poor differentiation alone, 34.7% with LVI alone, and 45.0% with both poor differentiation and LVI. For T2 tumors, positive lymph nodes were present in 11.7% with neither poor differentiation nor LVI, 25.3% with poor differentiation alone, 47.3% with LVI alone, and 41.5% with both poor differentiation and LVI. LVI was an independent predictor of positive lymph nodes (OR;4.75,95%CI;3.17-7.11,p < 0.001) for T1 and (OR;6.20,95%CI;4.53-8.51,p < 0.001) T2 tumors. CONCLUSIONS:T1/T2 tumors have higher rates of positive lymph nodes when poor differentiation and LVI are present. These results should be taken into consideration prior to surgical treatment.