Computed Tomography-Based Evaluation of Volume and Position Changes of the Target Region and Organs at Risk During Radiotherapy for Esophageal Cancer: A Pilot Study.
Frontiers in oncology
OBJECTIVE:To analyze changes in volume and position of target regions and organs at risk (OARs) during radiotherapy for esophageal cancer patients. METHODS:Overall, 16 esophageal cancer patients who underwent radiotherapy, including 10 cases of intensity-modulated radiation therapy (IMRT) and six of three-dimensional conformal radiotherapy (3D-CRT), were enrolled. The prescription doses for the planning target volumes (PTVs) were as follows: PTV1, 64 Gy/32 fractions; and PTV2, 46 Gy/23 fractions. Repeat computed tomography (CT) was performed for patients after the 5th, 10th, 15th, 20th, and 25th fractions. Delineation of the gross tumor volume (GTV) and OAR volume was determined using five repeat CTs performed by the same physician. The target and OAR volumes and centroid positions were recorded and used to analyze volume change ratio (VCR), center displacement (ΔD), and changes in the distance from the OAR centroid positions to the planned radiotherapy isocenter (distance to isocenter, DTI) during treatment. RESULTS:No patient showed significant changes in target volume (TV) after the first week of radiotherapy (five fractions). However, TV gradually decreased over the following weeks, with the rate slowing after the fourth week (40 Gy). The comparison of TV from baseline to 40 Gy (20 fractions) showed that average GTVs decreased from 130.7 ± 63.1 cc to 92.1 ± 47.2 cc, with a VCR of -29.21 ± 13.96% (<0.01), while the clinical target volume (CTV1) decreased from 276.7 ± 98.2 cc to 246.7 ± 87.2 cc, with a VCR of -10.34 ± 7.58% (<0.01). As TVs decreased, ΔD increased and DTI decreased. After the fourth week of radiotherapy (40 Gy), centroids of GTV, CTV1, and prophylactic CTV (CTV2) showed average deviations in ΔD of 7.6 ± 4.0, 6.9 ± 3.4, and 6.0 ± 3.0 mm, respectively. The average DTI of the heart decreased by 4.53 mm (from 15.61 ± 2.96 cm to 15.16 ± 2.27 cm). CONCLUSION:During radiotherapy for esophageal cancer, Targets and OARs change significantly in volume and position during the 2-4 weeks. Image-guidance and evaluation of dosimetric changes are recommended for these fractions of treatment to appropriate adjust treatment plans.
10.3389/fonc.2021.702400
Predictors of radiation-induced hypothyroidism in nasopharyngeal carcinoma survivors after intensity-modulated radiotherapy.
Zhai Ruiping,Lyu Yingchen,Ni Mengshan,Kong Fangfang,Du Chengrun,Hu Chaosu,Ying Hongmei
Radiation oncology (London, England)
BACKGROUND:The aim of the study is to identify clinical and dosimetric factors that could predict the risk of hypothyroidism in nasopharyngeal carcinoma (NPC) patients following intensity-modulated radiotherapy (IMRT). METHODS:A total of 404 non-metastatic NPC patients were included in our study. All patients were treated with IMRT. The thyroid function were performed for all patients before and after radiation at regular intervals. The time onset for developing hypothyroidism was defined as the time interval between the completion of RT and the first recorded abnormal thyroid hormone test. The cumulative incidence rates of hypothyroidism were estimated using Kaplan-Meier method. Univariate and multivariate Cox regression analyses were performed to detect the most promising factors that were associated with hypothyroidism. RESULTS:Median follow up was 60.6 months. The 3-, 5- and 7- year cumulative incidence rate of hypothyroidism was 39.4%, 49.1% and 54.7%, respectively. The median time to primary hypothyroidism and central hypothyroidism were 15.4 months (range 2.9-83.8 months) and 29.9 months (range 19.8-93.6 months), respectively. Univariate and multivariate analyses revealed that younger age, female gender and small thyroid volume were the most important factors in predicting the risk of hypothyroidism. Dtmean (mean dose of thyroid), V30-V50 (percentage of thyroid volume receiving a certain dose level) and VS45-VS60 (the absolute volumes of thyroid spared from various dose levels) remained statistically significant in multivariate analyses. Cutoff points of 45 Gy (Dtmean), 80% (Vt40) and 5 cm (VS45Gy) were identified to classify patients as high-risk or low-risk group. CONCLUSION:Thyroid Vt40 highly predicted the risk of hypothyroidism after IMRT for NPC patients. We recommended plan optimization objectives to reduce thyroid Vt40 to 80%. TRIAL REGISTRATION:Retrospectively registered.
10.1186/s13014-022-02028-z
Normal tissue complication probability (NTCP) models for predicting temporal lobe injury after intensity-modulated radiotherapy in nasopharyngeal carcinoma: A large registry-based retrospective study from China.
Wen Dan-Wan,Lin Li,Mao Yan-Ping,Chen Chun-Yan,Chen Fo-Ping,Wu Chen-Fei,Huang Xiao-Dan,Li Zhi-Xuan,Xu Si-Si,Kou Jia,Yang Xing-Li,Ma Jun,Sun Ying,Zhou Guan-Qun
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
PURPOSE:To develop predictive models with dosimetric and clinical variables for temporal lobe injury (TLI) in nasopharyngeal carcinoma (NPC) after intensity-modulated radiotherapy (IMRT). MATERIALS AND METHODS:Data of 8194 NPC patients who received IMRT-based treatment were retrospectively reviewed. TLI was diagnosed by magnetic resonance imaging. Dosimetric factors were selected by penalized regression and machine learning, with area under the receiver operating curve (AUC) calculated. Cox proportional hazards models containing the most predictive dosimetric factor with/without clinical variables were performed. A nomogram was generated as a visualization of Cox regression for predicting TLI-free survival. RESULTS:During median follow-up of 66.8 months (interquartile range [IQR] 54.2-82.2 months), 12.1% of patients (989/8194) developed TLI. Median latency from IMRT to TLI was 36 months (IQR 28-47 months). D (dose delivered to 0.5-cm temporal-lobe volume) was the most predictive dosimetric factor (AUC: 0.799). Tolerance dose for 5% and 50% probabilities to develop TLI in 5 years were 65.06 Gy (95% confidence interval [CI]: 64.19-65.92) and 89.75 Gy (95% CI: 87.39-92.11), respectively. A nomogram comprising age, T stage, and D significantly outperformed the model with only D in predicting TLI (C-index: 0.78 vs. 0.737 in train set; 0.775 vs. 0.73 in test set; both P < 0.001). The nomogram-defined high-risk group had worse 5-year TLI-free survival. CONCLUSIONS:D of 65.06 Gy was the tolerance dose of the temporal lobe. Reducing D decreased risk of TLI, especially in older patients with advanced T stage. The nomogram could predict TLI precisely and allow individualized follow-up management.
10.1016/j.radonc.2021.01.008
The prognostic value of weight loss during radiotherapy among patients with nasopharyngeal carcinoma: a large-scale cohort study.
BMC cancer
BACKGROUND:We aim to investigate the prognostic value of weight loss during radiotherapy (RT) among patients with nasopharyngeal carcinoma (NPC). METHODS:A total of 1149 NPC patients who received radical RT were retrospectively analyzed. Patients' weight were measured at initiation of RT (W) and every week during RT (W). Percentage of weight loss (PWL) at 1st, 2nd, 3rd, 4th, 5th, 6th, and 7th week of RT (RT-PWL) were calculated using the following equation: (W -W)/W × 100%. The optimal threshold of RT-PWL was determined by recursive partitioning analyses (RPAs). Our endpoints included disease-free survival (DFS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS). RESULTS:The median RT-PWLs were 0, 0, 1.5, 2.9, 4.1, 5.5, 6.6% at 1st, 2nd, 3rd, 4th, 5th, 6th, and 7th week of RT, respectively. RT-PWL optimal threshold with respect to DFS was 5.3% based on RPAs. Therefore, a consistent threshold of 5% (<5% vs > ≥5%) was selected to classify NPC patients into low RT-PWL and high RT-PWL groups for survival analysis. Compared to high RT-PWL (≥5%), patients with low RT-PWL (< 5%) had significantly better ten-year DFS (61.2% vs 78.8%; P < 0.001), OS (70.1% vs 86.6%; P < 0.001), and DMFS (80.2% vs 88.5%; P = 0.007). However, no difference was observed between LRRFS groups (91.7% vs 94.3%; P = 0.173). In multivariate analysis, high RT-PWL was an independent risk factor for DFS (HR, 1.56; 95%CI, 1.19-2.03; P = 0.001), OS (HR, 1.54; 95%CI, 1.11-2.15; P = 0.011), and DMFS (HR, 1.47; 95%CI, 1.03-2.10; P = 0.033) in patients with NPC. In addition, treatment strategy, plasma Epstein-Barr virus DNA, and N stage were associated with weight loss. CONCLUSIONS:High RT-PWL was significantly associated with decreased DFS, OS, and DMFS for NPC patients. Clinicians should continuously inform patients on the health impact of minimizing RT-PWL under 5% during radiotherapy.
10.1186/s12885-022-09562-9
Cochlea sparing optimized radiotherapy for nasopharyngeal carcinoma.
Lamaj Enkelejda,Vu Erwin,van Timmeren Janita E,Leonardi Chiara,Marc Louise,Pytko Izabela,Guckenberger Matthias,Balermpas Panagiotis
Radiation oncology (London, England)
BACKGROUND:Definitive chemoradiotherapy (CRT) is standard of care for nasopharyngeal carcinoma. Due to the tumor localization and concomitant platinum-based chemotherapy, hearing impairment is a frequent complication, without defined dose-threshold. In this study, we aimed to achieve the maximum possible cochleae sparing. MATERIALS AND METHODS:Treatment plans of 20 patients, treated with CRT (6 IMRT and 14 VMAT) based on the QUANTEC organs-at-risk constraints were investigated. The cochleae were re-delineated independently by two radiation oncologists, whereas target volumes and other organs at risk (OARs) were not changed. The initial plans, aiming to a mean cochlea dose < 45 Gy, were re-optimized with VMAT, using 2-2.5 arcs without compromising the dose coverage of the target volume. Mean cochlea dose, PTV coverage, Homogeneity Index, Conformity Index and dose to other OAR were compared to the reference plans. Wilcoxon signed-rank test was used to evaluate differences, a p value < 0.05 was considered significant. RESULTS:The re-optimized plans achieved a statistically significant lower dose for both cochleae (median dose for left and right 14.97 Gy and 18.47 Gy vs. 24.09 Gy and 26.05 Gy respectively, p < 0.001) compared to the reference plans, without compromising other plan quality parameters. The median NTCP for tinnitus of the most exposed sites was 11.3% (range 3.52-91.1%) for the original plans, compared to 4.60% (range 1.46-90.1%) for the re-optimized plans (p < 0.001). For hearing loss, the median NTCP of the most exposed sites could be improved from 0.03% (range 0-99.0%) to 0.00% (range 0-98.5%, p < 0.001). CONCLUSIONS:A significantly improved cochlea sparing beyond current QUANTEC constraints is feasible without compromising the PTV dose coverage in nasopharyngeal carcinoma patients treated with VMAT. As there appears to be no threshold for hearing toxicity after CRT, this should be considered for future treatment planning.
10.1186/s13014-021-01796-4
The Efficacy of Radiotherapy for Nasopharyngeal Carcinoma under Magnetic Resonance Imaging.
Zhang Hao,Guo Linlin,He Pengfei,Chang Zheng
Contrast media & molecular imaging
This study aimed to analyze the application value of diffusion tensor imaging (DTI) in the diagnosis of nasopharyngeal carcinoma (NC) radiotherapy. In this study, 102 patients with NC were selected as the experimental group (EG), and 58 healthy people examined in hospital were included in a control group (CG). All subjects were required to be examined with routine magnetic resonance imaging (MRI) and DTI before and after the treatment. The fractional anisotropy (FA) of the patients in EG before and after treatment and the CG were recorded. The apparent diffusion coefficients (ADC) of patients in the two groups were measured and recorded before and after the treatment. The recovery rate and adverse events of the patients in EG were observed and recorded after the treatment. The results showed that the FA values of the right cerebellum and left parietal lobe (LPL) of patients after treatment in the EG were much higher than those before treatment and the CG ( < 0.05); the FA values of the right temporal lobe (RTL), right occipital lobe (ROL), and right parietal lobe (RPL) after treatment in the EG were obviously lower than those before the treatment and the CG ( < 0.05); the complete remission rate (CRR) of the EG after treatment was greatly higher than the partial remission rate (PRR) and disease stability rate (DSR) ( < 0.05), and the objective remission rate (ORR) and disease control rate (DCR) were higher than 90%, respectively. The ADC value of the EG before treatment was (0.752 ± 0.021) × 10 mm/s, which was visibly lower than that after treatment ((1.365 ± 0.058) × 10 mm/s) and that in the CG ((1.856 ± 0.079)) × 10 mm/s), showing statistically obvious differences ( < 0.05). The incidence of anemia, oral reactions, hypertension, and gastrointestinal reaction in the EG after treatment was 61.46%, 45.35%, 47.28%, and 39.67%, respectively. In short, the FA value of DTI parameter could clearly indicate the changes in brain area characteristics of NC patients before and after treatment. The RTL, ROL, and RPL of NC patients were damaged after radiotherapy, and the FA value decreased observably, which may be related to brain edema and demyelination changes. The damage of white matter microstructure in each brain area further affected the cognitive function of the patient.
10.1155/2021/8280479
Effect of Body Size Change on Off-Center Cervical Point and Face Doses in Patients Undergoing Nasopharyngeal Carcinoma Radiotherapy.
Disease markers
Nasopharyngeal carcinoma (NPC) is a clinically multiple malignant tumor. At present, with the increase in the infection rate of Epstein-Barr virus, the incidence of nasopharyngeal carcinoma is also increasing day by day. To explore the effect of body size change on off-center cervical point and face doses in patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy, in total, 100 patients with NPC from January 2019 to May 2020 in our hospital were selected for retrospective analysis, and they all received intensity-modulated radiation therapy. Bodyweight, horizontal longitudinal diameter of the odontoid process, longitudinal diameter of the third cervical spine, maximum radiation dose, and average radiation dose of normal organs in the first and last treatments were assessed, and the correlation between normal organ irradiation dose and body size was analyzed. Bodyweight, horizontal longitudinal diameter of the odontoid process, and longitudinal diameter of the third cervical spine in the last treatment were lower than those in the first treatment, with a statistically significant difference. There was no statistically significant difference in the maximum normal organ irradiation dose to the left eyeball, right eyeball, left crystalline lens, right crystalline lens, and maximum irradiation dose to optic nerve between the last treatment and the first treatment. In the last treatment, the maximum dose to the left parotid gland, right parotid gland, spinal cord, and brain stem was higher than that in the first treatment. The average irradiation dose to the left eye bulb, right eye bulb, left lens, right lens, optic nerve in the last treatment, and that in the first treatment showed no significant difference. The average dose to the left parotid gland, right parotid gland, spinal cord, and brain stem in the last treatment was higher than that in the first treatment. The irradiation dose to the left parotid gland, right parotid gland, spinal cord, and brain stem was significantly negatively correlated with body weight, horizontal longitudinal diameter of the odontoid process, and longitudinal diameter of the third cervical spine. After NPC radiotherapy, the body size of patients can change, which can have different effects on irradiation doses. Therefore, the target area and dose should be corrected during treatment to ensure the efficacy and safety of the treatment.
10.1155/2022/9978282
Quality of life and survival outcome for patients with nasopharyngeal carcinoma treated by volumetric-modulated arc therapy versus intensity-modulated radiotherapy.
Huang Tai-Lin,Tsai Ming-Hsien,Chuang Hui-Ching,Chien Chih-Yen,Lin Yu-Tsai,Tsai Wen-Ling,Fang Fu-Min
Radiation oncology (London, England)
BACKGROUND:To evaluate the longitudinal changes of quality of life (QoL) and survival in patients with nasopharyngeal carcinoma (NPC) treated by volumetric-modulated arc therapy (VMAT) versus intensity-modulated radiotherapy (IMRT). METHODS:One hundred and forty non-distant metastatic NPC patients treated by VMAT (n = 66) or IMRT (n = 74) with simultaneously integrated boost between March 2013 and December 2015 at a single institute were analyzed. QoL was prospectively assessed by the EORTC QLQ-C30 and HN35 questionnaires at the four time points: before RT, RT 42.4 Gy (20 fractions), and 3, 12 months after RT. RESULTS:The 3-year locoregional relapse-free survival, distant metastasis-free survival, failure-free survival, and overall survival rates were 96.6, 89.4, 86.1%, and 87.4 for the VMAT group, respectively, compared with 91.4, 90.0, 79.8, and 91.3% for the IMRT group (p value > 0.05). The pattern of QoL changes was similar between the VMAT and IMRT group. No statistically or clinically significant difference in all the QoL scales was observed between VMAT and IMRT group at each time point. Compared to before RT, we observed statistically (p<0.05) and clinically (difference of mean scores≧10) better outcome in global QoL and social functioning, but worse head and neck symptomatic outcome in swallowing, taste/smell, opening mouth, dry mouth, and sticky saliva at the time point of 1 year after RT for both groups. CONCLUSION:The study provides the evidence that the tumor control, survival and changes of QoL is compatible for NPC patients treated by VMAT versus IMRT.
10.1186/s13014-020-01532-4
Thyroid dose-volume thresholds for the risk of radiation-related hypothyroidism in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy-A single-institution study.
Huang Cheng-Long,Tan Hong-Wen,Guo Rui,Zhang Yuan,Peng Hao,Peng Liang,Lin Ai-Hua,Mao Yan-Ping,Sun Ying,Ma Jun,Tang Ling-Long
Cancer medicine
BACKGROUND:To identify thyroid dose-volume thresholds for radiotherapy (RT)-related hypothyroidism (HT) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated RT (IMRT). In this way, we desired to guide the design of treatment plans and, finally, lower HT prevalence. METHODS:In total, 345 NPC patients treated with IMRT were evaluated retrospectively during a median follow-up of 45.2 (range, 11.3-64.9) months. Serum-based assessments of thyroid function before and after IMRT were monitored periodically. Thyroid dose-volume parameters were analyzed for their association with HT risk. RESULTS:In total, 44.1% of patients (152/345) developed primary HT. Analyses of thyroid dose-volume parameters identified a stringent dose-volume histogram (DVH) threshold defined by V (the percentage thyroid volume that receives >25 Gy, not the absolute volume) ≤60%, V ≤ 55%, and V ≤ 45%. Patients whose thyroid DVHs satisfied these constraints had a lower prevalence of 2-year HT compared with the overall prevalence (13.2% vs 25.8%, P < .001). Another DVH was defined by V > 95%, V > 90%, and V > 75%, and patients whose thyroid DVHs satisfied with these constraints had a higher prevalence of 2-year HT than the overall incidence (36.0% vs 25.8%, P < .001). CONCLUSION:We recommend V ≤ 60%, V ≤ 55%, and V ≤ 45% as the "stringent" DVH line, and V > 95%, V > 90%, and V > 75% as the "inhibition" DVH line, under the precondition of not compromising the target coverage. These findings could help in the design of individual treatment plans and, eventually, to lowering of HT prevalence.
10.1002/cam4.2574
Impact of CBCT frequency on target coverage and dose to the organs at risk in adjuvant breast cancer radiotherapy.
Borm Kai J,Junker Yannis,Düsberg Mathias,Devečka Michal,Münch Stefan,Dapper Hendrik,Oechsner Markus,Combs Stephanie E
Scientific reports
The current study aims to assess the effect of cone beam computed tomography (CBCT) frequency during adjuvant breast cancer radiotherapy with simultaneous integrated boost (SIB) on target volume coverage and dose to the organs at risk (OAR). 50 breast cancer patients receiving either non-hypofractionated or hypofractionated radiotherapy after lumpectomy including a SIB to the tumor bed were selected for this study. All patients were treated in volumetric modulated arc therapy (VMAT) technique and underwent daily CBCT imaging. In order to estimate the delivered dose during the treatment, the applied fraction doses were recalculated on daily CBCT scans and accumulated using deformable image registration. Based on a total of 2440 dose recalculations, dose coverage in the clinical target volumes (CTV) and OAR was compared depending on the CBCT frequency. The estimated delivered dose (V95%) for breast-CTV and SIB-CTV was significantly lower than the planned dose distribution, irrespective of the CBCT-frequency. Between daily CBCT and CBCT on alternate days, no significant dose differences were found regarding V95% for both, breast-CTV and SIB-CTV. Dose distribution in the OAR was similar for both imaging protocols. Weekly CBCT though led to a significant decrease in dose coverage compared to daily CBCT and a small but significant dose increase in most OAR. Daily CBCT imaging might not be necessary to ensure adequate dose coverage in the target volumes while efficiently sparing the OAR during adjuvant breast cancer radiotherapy with SIB.
10.1038/s41598-021-96836-0