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    [What is the impact of IMRT of nasopharyngeal carcinomas on glandular structures?] Mnejja W,Daoud H,Fourati N,Sahnoun T,Siala W,Farhat L,Daoud J Cancer radiotherapie : journal de la Societe francaise de radiotherapie oncologique PURPOSE:The aim of this work is to evaluate the anatomical changes of the glandular structures during the NPC IMRT and to study their dosimetric impacts. PATIENTS AND METHODS:Twenty patients receiving IMRT for NPC were included. For each patient, a second dosimetric CT was performed at a dose of 38Gy, which was fused with the initial planning dosimetric CT. We calculated the volume percent change, the positional and dosimetric variation between the 2 scanners for the glandular structures (parotid, submaxillary, thyroid and pituitary). RESULTS:We observed a decrease in the volume of right and left parotids (-27.9% and -27.54%). It was correlated with the initial dose planned at its level. For the sub maxillary glands, the decrease was -36.1% on the right and -27.28% on the left. The value of reduction of the thyroid gland was -18.01%. A medial supra-millimeter migration of 2 and 1.15mm was found for right and left parotid glands respectively, correlated with GTV N reduction volume. We found a significant increase in mean doses for the parotid glands. It was 1.8±2.3Gy for the right and 1.5±2.7Gy for the left. For the right sub maxillary gland, the increase was about 0.35±2Gy and 3.79±5.2Gy for the thyroid. CONCLUSION:The modifications observed for glandular structures during NPC IMRT can explain the different toxicities caused by radiation. It seems also that a careful adaptation of the treatment plan should be considered during therapy. 10.1016/j.canrad.2019.06.015
    Long-Term Progression of Sensorineural Hearing Loss and Tinnitus after Combined Intensity-Modulated Radiation Therapy and Cisplatin-Based Chemotherapy for Nasopharyngeal Carcinoma: A Case Report. Lee Ming S,Penumala Sudha,Sweet Steven,De Luca Russell R,Stearnes Ariel E,Akgun Yamac Case reports in oncology Sensorineural hearing loss (SNHL) is a common adverse effect for nasopharyngeal carcinoma (NPC) patients treated with chemoradiotherapy. We report a case of 12-year follow-up from a patient with stage IIB NPC, treated in 2004 with intensity-modulated radiotherapy and cisplatin-based chemotherapy. Pure-tone audiograms were conducted before treatment and at two other points in the 12-year period after treatment. Analysis of the patient's audiograms reveals that the development of high-frequency SNHL started after treatment and reached a plateau accompanied by tinnitus approximately 32 months after treatment conclusion. After the plateau, high-frequency SNHL continued to develop slowly in the next 10 years, possibly a long-term effect from radiation-induced microvascular change of the hearing apparatus. The continuous high-frequency hearing decline is associated with increased tinnitus pitch in the patient. With experience learned from this case, we recommend hearing tests at regular intervals for at least 3-5 years for NPC patients treated with chemoradiotherapy. Patients need to be educated about tinnitus and counseling can be offered when they begin to feel inconvenienced by tinnitus. These patients also need to be advised against exposure to noise that can aggravate the already compromised hearing apparatus, leading to further hearing loss and worsening tinnitus. Limiting the peak dose and total cumulative dose of cisplatin should be considered based on the patients' risk factors to achieve a balance between treatment efficacy and long-term adverse effects. 10.1159/000478847
    The Long-Term Recovery of Parotid Glands in Nasopharyngeal Carcinoma Treated by Intensity-Modulated Radiotherapy. Frontiers in oncology BACKGROUND:Xerostomia is one of the most common adverse events of radiotherapy in head and neck cancer patients. There have been many reports on functional changes of the parotid gland after radiation therapy, but there have been few reports on the volume of the parotid gland and its relationship with oral quality of life (QOL) and even fewer reports on longitudinal change of the parotid gland volume. The purpose of this study was to evaluate the long-term change of the parotid gland volume after intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma and the relationship between parotid irradiation dose and xerostomia symptoms. METHODS:We retrospectively analyzed 26 patients with nasopharyngeal cancer treated by IMRT. Longitudinal changes of parotid gland volumes after IMRT were evaluated on CT images. The parotid gland volumes in each period were converted to the ratio to parotid gland volumes before radiotherapy (relative parotid volume). Dunnett's test was used to evaluate the longitudinal changes in relative parotid volumes at 0-6, 7-18, 19-30, 31-42, 43-54 and 55-66 months after IMRT. We assessed xerostomia 3 years or more after IMRT by measuring the degree of oral moisture using a moisture-checking device (Mucus, Life Co., Ltd.) and oral QOL evaluation by GOHAI (General Oral Health Assessment Index). RESULTS:The relative parotid volumes during radiotherapy and at 0-6, 7-18, 19-30, 31-42, 43-54 and 55-66 months after IMRT were 75.2 ± 14.3%, 67.2 ± 11.4%, 68.5 ± 15.9%, 72.4 ± 14.8%, 73.0 ± 13.8%, 76.2 ± 17.5%, and 77.1% ± 17.3%, respectively. The parotid volume had recovered significantly at 43-54 and 55-66 months after IMRT, especially in parotids receiving less than 40 Gy as the mean dose. The mean irradiated dose for bilateral parotids showed negative correlations with oral QOL score and oral moisture after a long period. CONCLUSIONS:The parotid volume recovered gradually but had not reached a plateau even 3 years after radiotherapy, especially in parotids receiving less than 40 Gy as the mean dose. 10.3389/fonc.2021.665837
    Study of the dose-volume parameters variation in tumor target volumes and organs at risk during nasopharyngeal carcinoma radiotherapy applying deformation registration. Translational cancer research BACKGROUND:During intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC), the volume of the target volume and the organs at risk (OARs) will change constantly, which may lead to differences between the actual dose received and the initial planned dose. In this study, the cumulative dose of the two plans was obtained by deformable registration. This study provides an approach to evaluate the dose volume of IMRT for the NPC objective. METHODS:From July 2014 to May 2018, eighteen NPC patients who accepted simultaneous integrated boost IMRT were enrolled. All patients underwent simulation CT (CT) and replanning CT (CT) scans after 20-25 fractions of radiation therapy. The treatment plans were designed on CT and CT with the name of Plan and Plan, respectively. The Plan and Plan were obtained after registering from CT to CT using rigidity and deformation technology by Velocity. Then the dose-volume indices of the tumor target volumes and OARs at Plan, Plan, Plan and Plan were compared. RESULTS:The gross tumor volume (GTV) and the left and right parotid gland volumes decreased by 20.8% (P<0.001), 36.8% (P<0.001) and 37.5% (P<0.001), respectively, from CT to CT. There was no significant difference in the dose-volume index on the GTV and plan gross tumor volume (PGTV) between Plan and Plan. The V of the left and right parotid gland and the D of the brainstem, left and right eyeballs, left and right lens, and left and right optic nerves were all lower in Plan than in Plan (the average decrease was 17.0% to 60.1%). The differences in some dose-volume parameters (including D, D of the GTV and PGTV, D of the parotid glands, D of the lens and optic nerves) between Plan and Plan were less than 5%. The differences in some dose-volume parameters (including D, D of the GTV and PGTV, D, D and V of the parotid glands, D of lens and optic nerves) between Plan and Plan were less than 10%. The Dyce Similarity Coefficient of the target volume and OARs after deformation registration were higher than that after rigid registration. CONCLUSIONS:The volume of the GTV and parotid glands were decreased during the IMRT for NPC. The dose-volume indices of the GTV and the OARs in Plan were similar to those in Plan. Therefore, the dose-volume indices of Plan can be used to evaluate the efficacy of radiotherapy and to predict radioactive damage. 10.21037/tcr.2019.11.06
    Dynamic Change of Amide Proton Transfer Imaging in Irradiated Nasopharyngeal Carcinoma and Related Histopathological Mechanism. Song Qingxu,Chen Pengxiang,Chen Xin,Sun Cong,Wang Jianbo,Tan Bingxu,Liu Hong,Cheng Yufeng Molecular imaging and biology OBJECTIVE:To investigate the dynamic change of amide proton transfer (APT) imaging before and after irradiation in nasopharyngeal carcinoma (NPC) and the underlying histopathological mechanism. MATERIALS AND METHODS:Tumor-bearing BALB/C nude mouse models were established and randomly divided into three groups: high-dose group (20 Gy/2 fractions), low-dose group (10 Gy/2 fractions), and control group (0 Gy). MRI scanning was performed before irradiation and 3rd, 6th, and 9th day post-irradiation. Scanning sequence included T1 weighted, T2 weighted, and APT. HE staining and TUNEL immunofluorescence detection were performed to detect necrosis and apoptosis. RESULTS:After high-dose irradiation, the mean tumor APT values decreased significantly on the 3rd day and 6th day (from 3.83 before radiotherapy to 2.41%, P < 0.001, 3rd day; from 2.41 to 1.80%, P = 0.001, 6th day). For low-dose irradiation, the mean tumor APT values decreased slightly on the 3rd day and 6th day (from 3.52 to 3.13%, P = 0.109, 3rd day; from 3.13 to 3.05%, P = 0.64, 6th day). The mean APT values of nonirradiated tumor changed slightly. In contrast, the average volume of high-dose irradiated tumors did not decrease obviously until the 9th day post-irradiation (from 290 before radiotherapy to 208 mm on the 9th day). The low-dose irradiated tumors showed slow growth, and the nonirradiated tumors showed rapid growth. Subsequent HE staining and TUNEL staining showed obvious necrosis characteristics and higher proportion of positive apoptotic cell nucleus in high-dose irradiated tumors, but not nonirradiated tumors. CONCLUSION:The APT signal intensity decreased after irradiation, which is earlier than the change of tumor volume. What is more, the decrease of APT signal intensity is more significant in high-dose group. Histological analysis showed obvious apoptosis and necrosis histological characteristic in irradiated tumor, which may explain the decrease of APT signal intensity. These results indicate that APT imaging has the potential to serve as a reliable biomarker for response assessment in NPC. 10.1007/s11307-021-01607-y
    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
    Early Prediction of Acute Xerostomia During Radiation Therapy for Head and Neck Cancer Based on Texture Analysis of Daily CT. Wu Hui,Chen Xiaojian,Yang Xin,Tao Yalan,Xia Yunfei,Deng Xiaowu,Zheng Cheng,Robbins Jared,Schultz Christopher,Li X Allen International journal of radiation oncology, biology, physics PURPOSE:To investigate radiation-induced changes of computed tomography (CT) textures in parotid glands (PG) to predict acute xerostomia during radiotherapy (RT) for head and neck cancer (HNC). METHODS AND MATERIALS:Daily or fraction kilovoltage CTs acquired using diagnostic CT scanners (eg, in-room CTs) during intensity-modulated RT for 59 HNC patients at 3 institutions were analyzed. The PG contours were generated on selected daily/fraction CTs. A series of histogram-based texture features, including the mean CT number (MCTN) in Hounsfield units, volume, standard deviation, skewness, kurtosis, and entropy for PGs were calculated for each fraction. Correlations between the changes of the texture features, radiation dose, and observed acute xerostomia were analyzed. A classifier model and the incurred CT-based xerostomia score (CTXS) were introduced to predict xerostomia based on combined changes of MCTN and volume of PGs. The t test and Spearman and Pearson correlation tests were used in the analyses. RESULTS:Substantial changes in various CT texture features of PGs were observed during RT delivery. The changes of PG MCTN or volume are not strongly correlated with the observed xerostomia grades if they are considered separately. The CTXS showed a significant correlation to the observed xerostomia grades (r = 0.71, P < .00001). The CTXS-based classifier can predict the xerostomia severity with a success rate ranging from 79% to 98%. The xerostomia severity at the end of treatment can be predicted based on the CTXS determined at the fifth week with a precision and sensitivity of 100%. CONCLUSION:Significant changes in the CT histogram features of the parotid glands were observed during RT of HNC. A practical method of using the changes of MCTN and volume of PGs is proposed to predict radiation-induced acute xerostomia, which may be used to help design adaptive treatment. 10.1016/j.ijrobp.2018.04.059
    Analysis of volumetric and dosimetric changes in mid treatment CT scan in carcinoma nasopharynx: implications for adaptive radiotherapy. Bahl Amit,Elangovan Arun,Dracham Chinna Babu,Kaur Satinder,Oinam Arun Singh,Trivedi Gaurav,Verma Roshan,Panda Naresh K,Ghoshal Sushmita Journal of experimental therapeutics & oncology OBJECTIVE:Carcinoma of nasopharynx is a radiosensitive tumor and therapeutic response during radiation treatment can result in dosimetric variations in the delivered dose to the tumor and critical organs. This study was done to evaluate the volumetric and dosimetric changes seen in tumor tissue and organs at risk in a mid treatment planning scan and its implications for adaptive replanning. Twenty patients of locally advanced carcinoma nasopharynx were evaluated. All patients were started on treatment with a baseline treatment plan on SIB-VMAT. To evaluate volumetric and dosimetric changes during treatment, a mid treatment CT scan (MTS) was taken at the 17 fraction of treatment and compared with the baseline planning CT scan (BS). Adaptive treatment plans were generated on the MTS and further treatment was continued on the adaptive plans. The mean weight loss observed at the 17th fraction of treatment was 3.4 ± 2.6 kg(Mean±S.D). The mean neck diameter at C2 level was 14.19±1.02 and 13.29 ± 1.14 cm in the BS and MTS respectively (p=0.001). The GTV 70 volume showed a 29.16% volume loss. The mean doses received by the right and left parotids were 25.45±0.98 and 24.64±3.8 Gy in the baseline treatment plan and 33.21±11.29 (p=0.054) and 31.76±8.44 Gy respectively in the MTS (p=0.016) The mean weight loss showed a statistically significant correlation with increase in the right parotid(p=0.043) and left parotid doses(p=0.024). Weight loss during treatment combined with volume changes in target tissues mandate routine adaptive replanning while treating carcinoma nasopharynx.
    Radiotherapy for Head and Neck Cancer: Evaluation of Triggered Adaptive Replanning in Routine Practice. Figen Metin,Çolpan Öksüz Didem,Duman Evrim,Prestwich Robin,Dyker Karen,Cardale Kate,Ramasamy Satiavani,Murray Patrick,Şen Mehmet Frontiers in oncology Purpose and Objective:A proportion of patients receiving radiotherapy for head and neck squamous cell carcinoma (HNSCC) require treatment re-planning. The aim of this retrospective study is to analyze the patients who required re-planning and to identify factors, which may predict need for re-planning. Materials and Methods:A single center evaluation of all patients receiving radical or adjuvant (chemo)radiotherapy (CRT) for HNSCC between January and December 2016 was undertaken. Patients who underwent re-planning during the treatment were identified in electronic records. Reasons for re-planning were categorized as: weight loss, tumor shrinkage, changes in patient position and immobilization-related factors. Potential trigger factors for adaptive radiotherapy such as patient characteristics, primary tumor site, stage, concomitant chemotherapy, weight loss ratios, radical/adjuvant treatment, and nutritional interventions were investigated. Results:31/290 (10.6%) HNSCC patients who underwent radical/adjuvant radiotherapy required re-planning. The adaptive radiotherapy (ART) was performed at a mean fraction of 15. The most common documented reasons for re-planning were tumor shrinkage (35.5%) and weight loss (35.5%). Among the patient/tumor/treatment factors, nasopharyngeal primary site (p = 0.013) and use of concurrent chemotherapy with radiotherapy (p = 0.034) were found to be significantly correlated with the need for re-planning. Conclusion:Effective on-treatment verification schedules and close follow up of patients especially with NPC primary and/or treated with concurrent chemoradiotherapy are crucial to identify patients requiring ART. We suggest an individualized triggered approach to ART rather than scheduled strategies as it is likely to be more feasible in terms of utilization of workload and resources. 10.3389/fonc.2020.579917
    Analysis of geometric variation of neck node levels during image-guided radiotherapy for nasopharyngeal carcinoma: recommended planning margins. Tan Wenyong,Wang Yingjie,Yang Ming,Amos Richard A,Li Weihao,Ye Jianzeng,Gary Royle,Shen Weixi,Hu Desheng Quantitative imaging in medicine and surgery BACKGROUND:To quantify the geometrical changes of each neck nodal level (NNL) and estimate the geometric planning target volume (PTV) margin during image-guided radiotherapy (IGRT) for nasopharyngeal cancer (NPC). METHODS:Twenty patients with locally advanced NPC underwent one planning computed tomography (CT) and 6 weekly repeat CT (CT) scans during chemoradiotherapy. Each CT was rigidly registered to the CT. All the NNLs were manually delineated in each transverse CT section. When comparing the NNL in CT with CT, their volumes, displacement of the center of the mass, and the shortest perpendicular distance (SPD) were automatically calculated. This was followed by calculation of the systematic and random errors, overlapping index (OI), and dice similarity coefficient (DSC). With PTVs isotropically expanded from NNL by 1, 2, 3, 4, and 5 mm, they were compared with NNL itself; OI >0.95 was defined as the acceptable geometrical coverage. The Mann-Whitney test was used for statistical analysis. RESULTS:All volumes, OI, and DSC of the NNLs (not including level IA) showed a linear decrease over time throughout the treatment course. The volume of NNLs decreased by 1-6% in the first week and 10-21% in the sixth week. The mean SPD was 1.3-1.7 and 1.9-3.5 mm in the first and sixth week respectively. The DSCs for nodal level IB, II, III, and IV were >0.7 and that of level V was <0.7 throughout the treatment course. For level IA and VI, DSC was <0.7 after the 2nd week. To maintain the OI >0.95, 2-5 mm was needed to expand the different NNLs. CONCLUSIONS:The geometrical changes of each NNL are substantial and the necessary margin of 2-5 mm depended on individual NNL is needed to maintain geometrical coverage throughout the course of IGRT for NPC. 10.21037/qims.2018.08.03
    Adaptive radiotherapy for head and neck cancer: Are we ready to put it into routine clinical practice? Gensheimer Michael F,Le Quynh-Thu Oral oncology Patients with head and neck cancer who are treated with radiotherapy often have significant weight loss or tumor regression during treatment. Adaptive radiotherapy refers to acquiring new imaging during treatment and changing the parameters of the radiation plan based on the new imaging findings. There is accumulating evidence that adaptive radiotherapy can reduce toxicity and improve tumor control, though it is not yet known which patients benefit most. For patients with profound tumor regression, there is also uncertainty about how much to shrink the region receiving high radiation dose. Another form of adaptive radiotherapy uses advanced imaging such as positron emission tomography to visualize changes in tumor biology during treatment. Tumor regions that are thought to be more radioresistant can then be treated to a higher radiation dose, and vice-versa. Studies employing this strategy to boost radiation dose have shown a high rate of late toxicity, specifically the development of persistent mucosal ulcers. Therefore, this sort of adaptive radiotherapy is currently confined to the research setting. 10.1016/j.oraloncology.2018.08.010
    Pretreatment Prediction of Adaptive Radiation Therapy Eligibility Using MRI-Based Radiomics for Advanced Nasopharyngeal Carcinoma Patients. Yu Ting-Ting,Lam Sai-Kit,To Lok-Hang,Tse Ka-Yan,Cheng Nong-Yi,Fan Yeuk-Nam,Lo Cheuk-Lai,Or Ka-Wa,Chan Man-Lok,Hui Ka-Ching,Chan Fong-Chi,Hui Wai-Ming,Ngai Lo-Kin,Lee Francis Kar-Ho,Au Kwok-Hung,Yip Celia Wai-Yi,Zhang Yong,Cai Jing Frontiers in oncology Adaptive radiotherapy (ART) can compensate for the dosimetric impacts induced by anatomic and geometric variations in patients with nasopharyngeal carcinoma (NPC); Yet, the need for ART can only be assessed during the radiation treatment and the implementation of ART is resource intensive. Therefore, we aimed to determine tumoral biomarkers using pre-treatment MR images for predicting ART eligibility in NPC patients prior to the start of treatment. Seventy patients with biopsy-proven NPC (Stage II-IVB) in 2015 were enrolled into this retrospective study. Pre-treatment contrast-enhanced T1-w (CET1-w), T2-w MR images were processed and filtered using Laplacian of Gaussian (LoG) filter before radiomic features extraction. A total of 479 radiomics features, including the first-order ( = 90), shape ( = 14), and texture features ( = 375), were initially extracted from Gross-Tumor-Volume of primary tumor (GTVnp) using CET1-w, T2-w MR images. Patients were randomly divided into a training set ( = 51) and testing set ( = 19). The least absolute shrinkage and selection operator (LASSO) logistic regression model was applied for radiomic model construction in training set to select the most predictive features to predict patients who were replanned and assessed in the testing set. A double cross-validation approach of 100 resampled iterations with 3-fold nested cross-validation was employed in LASSO during model construction. The predictive performance of each model was evaluated using the area under the receiver operator characteristic (ROC) curve (AUC). In the present cohort, 13 of 70 patients (18.6%) underwent ART. Average AUCs in training and testing sets were 0.962 (95%CI: 0.961-0.963) and 0.852 (95%CI: 0.847-0.857) with 8 selected features for CET1-w model; 0.895 (95%CI: 0.893-0.896) and 0.750 (95%CI: 0.745-0.755) with 6 selected features for T2-w model; and 0.984 (95%CI: 0.983-0.984) and 0.930 (95%CI: 0.928-0.933) with 6 selected features for joint T1-T2 model, respectively. In general, the joint T1-T2 model outperformed either CET1-w or T2-w model alone. Our study successfully showed promising capability of MRI-based radiomics features for pre-treatment identification of ART eligibility in NPC patients. 10.3389/fonc.2019.01050
    Potential benefits of adaptive intensity-modulated proton therapy in nasopharyngeal carcinomas. Minatogawa Hideki,Yasuda Koichi,Dekura Yasuhiro,Takao Seishin,Matsuura Taeko,Yoshimura Takaaki,Suzuki Ryusuke,Yokota Isao,Fujima Noriyuki,Onimaru Rikiya,Shimizu Shinichi,Aoyama Hidefumi,Shirato Hiroki Journal of applied clinical medical physics PURPOSE:To investigate potential advantages of adaptive intensity-modulated proton beam therapy (A-IMPT) by comparing it to adaptive intensity-modulated X-ray therapy (A-IMXT) for nasopharyngeal carcinomas (NPC). METHODS:Ten patients with NPC treated with A-IMXT (step and shoot approach) and concomitant chemotherapy between 2014 and 2016 were selected. In the actual treatment, 46 Gy in 23 fractions (46Gy/23Fx.) was prescribed using the initial plan and 24Gy/12Fx was prescribed using an adapted plan thereafter. New treatment planning of A-IMPT was made for the same patients using equivalent dose fractionation schedule and dose constraints. The dose volume statistics based on deformable images and dose accumulation was used in the comparison of A-IMXT with A-IMPT. RESULTS:The means of the D of the right parotid gland (P < 0.001), right TM joint (P < 0.001), left TM joint (P < 0.001), oral cavity (P < 0.001), supraglottic larynx (P = 0.001), glottic larynx (P < 0.001), , middle PCM (P = 0.0371), interior PCM (P < 0.001), cricopharyngeal muscle (P = 0.03643), and thyroid gland (P = 0.00216), in A-IMPT are lower than those of A-IMXT, with statistical significance. The means of, D , and D of each sub portion of auditory apparatus and D for Eustachian tube and D for mastoid volume in A-IMPT are significantly lower than those of A-IMXT. The mean doses to the oral cavity, supraglottic larynx, and glottic larynx were all reduced by more than 20 Gy (RBE = 1.1). CONCLUSIONS:An adaptive approach is suggested to enhance the potential benefit of IMPT compared to IMXT to reduce adverse effects for patients with NPC. 10.1002/acm2.13128
    Long-term outcomes of replanning during intensity-modulated radiation therapy in patients with nasopharyngeal carcinoma: An updated and expanded retrospective analysis. Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology BACKGROUND AND PURPOSE:Recent studies show that adaptive replanning for patients with nasopharyngeal carcinoma (NPC) during intensity-modulated radiation therapy (IMRT) improve the short-term local-regional recurrence-free survival (LRFS), and quality of life (QoL). We aimed to assess the long-term survival outcomes and QoL in patients with non-metastatic NPC who received IMRT with replanning compared to those who received IMRT without replanning. METHODS AND MATERIALS:We conducted an updated and expanded retrospective analysis from an existing prospective cohort for non-metastatic NPC patients undergoing IMRT in our institution. Non-metastatic NPC patients receiving IMRT from June 2007 to December 2015 were consecutively enrolled based on electronic medical record. Patients who were still alive were eligible for the QoL study. The survival outcomes and QoL were compared between patients with and without replanning. RESULTS:Among 290 patients, 147 (50.7%) received IMRT without replanning and 143 (49.3%) received IMRT with replanning. Replanning group had a higher 8-year LRFS rate (87.4% vs. 75.6%, P = 0.025). However, 8-year overall survival rate was not statistically significant. Patients with replanning compared to those who without replanning had significant improvements in social functioning (P = 0.016), insomnia (P = 0.048), dry mouth (P = 0.004), and sticky saliva (P = 0.005). Additionally, the score of the role functioning was marginally higher in patients treated with IMRT replanning (P = 0.063). CONCLUSION:This extended follow-up study demonstrates the long-term security and validity for adaptive radiotherapy in IMRT for non-metastatic NPC patients. We highly recommend that adaptive replanning should be routinely implemented for non-metastatic NPC patients. 10.1016/j.radonc.2022.03.007
    Quantifying the dosimetric effects of neck contour changes and setup errors on the spinal cord in patients with nasopharyngeal carcinoma: establishing a rapid estimation method. Journal of radiation research The purpose of this study was to quantify the effect of neck contour changes and setup errors on spinal cord (SC) doses during the treatment of nasopharyngeal carcinoma (NPC) and to establish a rapid dose estimation method. The setup errors and contour changes in 60 cone-beam computed tomography (CBCT) images of 10 NPC patients were analysed in different regions of the neck (C1-C3, C4-C5 and C6-C7). The actual delivered dose to the SC was calculated using the CBCT images, and univariate simulations were performed using the planning CT to evaluate the dose effects of each factor, and an index ${\mathrm{Dmax}}_{\mathrm{displaced}}$ was introduced to estimate the SC dose. Compared with the planned dose, the mean (maximum) Dmax increases in the C1-C3, C4-C5 and C6-C7 regions of the SC were 2.1% (12.3%), 1.8% (8.2%) and 2.5% (9.2%), respectively. The simulation results showed that the effects of setup error in the C1-C3, C4-C5 and C6-C7 regions were 1.5% (9.7%), 0.9% (8.2%) and 1.3% (6.3%), respectively, and the effects of contour change were 0.4% (1.7%), 0.7% (2.5%) and 1.5% (4.9%), respectively. The linear regression model can be used to estimate the dose effect of contour changes (R2 > 0.975) and setup errors (R2 = 0.989). Setup errors may lead to a significant increase in the SC dose in some patients. This study established a rapid dose estimation method, which is of great significance for the daily dose evaluation and the adaptive re-planning trigger of the SC. 10.1093/jrr/rrac009
    Target delineation and dose prescription of adaptive replanning intensity-modulated radiotherapy for nasopharyngeal carcinoma. Xie Dehuan,Cheng Wanqin,Lv Shaowen,Zhong Rui,Wang Lei,Hu Jiang,Wang Mingli,Huang Shaomin,Su Yong,Xia Yunfei Cancer communications (London, England) 10.1186/s40880-019-0364-x
    Automatic segmentation for adaptive planning in nasopharyngeal carcinoma IMRT: Time, geometrical, and dosimetric analysis. Fung Nelson Tsz Cheong,Hung Wai Man,Sze Chun Kin,Lee Michael Chi Hang,Ng Wai Tong Medical dosimetry : official journal of the American Association of Medical Dosimetrists The aim of this study was to quantify the geometrical differences between manual contours and autocontours, the dosimetric impacts, and the time gain of using autosegmentation in adaptive nasopharyngeal carcinoma (NPC) intensity-modulated radiotherapy (IMRT) for a commercial system. A total of 20 consecutive Stages I to III NPC patients who had undergone adaptive radiation therapy (ART) re planning for IMRT treatment were retrospectively studied. Manually delineated organs at risks (OARs) on the replanning computed tomography (CT) were compared with the autocontours generated by VelocityAI using deformable registration from the original planning CT. Dice similarity coefficients and distance-to-agreements (DTAs) were used to quantify their geometric differences. IMRT test plans were generated with the assistance of RapidPlan based on the autocontours of OARs and manually segmented target volumes. The dose distributions were applied on the manually delineated OARs, their dose volume histograms and dose constraints compliances were analyzed. Times spent on target, OAR contouring, and IMRT replanning were recorded, and the total time of replanning using manual contouring and autocontouring were compared. The averaged mean DTA of all structures included in the study were less than 2 mm, and 90% of the patients fulfilled the mean distance agreement tolerance recommended by AAPM 132. The averaged maximum DTA for brainstem, cord, optic chiasm, and optic nerves were all less than 4 mm, whereas temporal lobes and parotids have larger average maximum DTA of 4.7 mm and 6.8 mm, respectively. It was found that large contour discrepancies in temporal lobes and parotids were often associated with large magnitude of deformation (warp distance) in image registrations. The resultant maximum dose of manually segmented brainstem, cord, and temporal lobe and the median dose of manually segmented parotids were found to be statistically higher than those to their autocontoured counter parts in test plans. Dose constraints of the manually segmented OARs in test plans were only met in 15% of the cases. The average time of manual contouring and autocontouring were 108 and 10 minutes, respectively (p < 0.001). More than 30% of the total replanning time would be spent in manual OAR contouring. Manual OAR delineation takes up a significant portion of time spent in ART replanning and OAR autocontouring could considerably enhance ART workflow efficiency. Geometrical discrepancies between auto- and manual contours in head and neck OARs were comparable to typical interobserver variation suggested in various literatures; however, some of the corresponding dosimetric differences were substantial, making it essential to carefully review the autocontours. 10.1016/j.meddos.2019.06.002
    [Adaptive radiotherapy for nasopharyngeal carcinomas: Where are we?] Hend Daoud,Mnejja Wafa,Fourati Nejla,Kallel Mouna,Siala Wicem,Sahnoun Tarek,Farhat Leila,Daoud Jamel Bulletin du cancer Modern high-precision radiotherapy techniques have recently incorporated the notion of anatomical variations of the patient during treatment and have tried to adapt the treatment planning to them. Adaptive radiotherapy for nasopharyngeal tumors is starting to prove its benefit nowadays. His interest is constantly being evaluated. The variations encountered during the treatment are both geometric and dosimetric. They are represented by a reduction in the macroscopic tumors volume, a change in its position and a consequent dosimetric impact. The changes also concern organs at risk with a reduction of glandular structure volumes, and a different position which increases their doses. Delivered doses to noble structures (brainstem and spinal cord) may also increase. However, difficulties are encountered in its realization. There is a problem to perfectly reproduce the patient position during the second acquisition, which impacts the fusion quality between the two CT scans. This generates an imprecision in the definition of the same treatment isocentre on the second scanner. Also, there is a difficulty in accumulated doses calculation. The indication of adaptive radiotherapy remains a subject of controversy. It should be proposed for a subgroup of patients who could benefit from this new strategy. We present here an update on the state of the art of adaptive radiotherapy for nasopharyngeal cancer. 10.1016/j.bulcan.2019.12.013
    A Multi-Center Study of CT-Based Neck Nodal Radiomics for Predicting an Adaptive Radiotherapy Trigger of Ill-Fitted Thermoplastic Masks in Patients with Nasopharyngeal Carcinoma. Lam Sai-Kit,Zhang Jiang,Zhang Yuan-Peng,Li Bing,Ni Rui-Yan,Zhou Ta,Peng Tao,Cheung Andy Lai-Yin,Chau Tin-Ching,Lee Francis Kar-Ho,Yip Celia Wai-Yi,Au Kwok-Hung,Lee Victor Ho-Fun,Chang Amy Tien-Yee,Chan Lawrence Wing-Chi,Cai Jing Life (Basel, Switzerland) Significant lymph node shrinkage is common in patients with nasopharyngeal carcinoma (NPC) throughout radiotherapy (RT) treatment, causing ill-fitted thermoplastic masks (IfTMs). To deal with this, an ad hoc adaptive radiotherapy (ART) may be required to ensure accurate and safe radiation delivery and to maintain treatment efficacy. Presently, the entire procedure for evaluating an eligible ART candidate is time-consuming, resource-demanding, and highly inefficient. In the artificial intelligence paradigm, the pre-treatment identification of NPC patients at risk for IfTMs has become greatly demanding for achieving efficient ART eligibility screening, while no relevant studies have been reported. Hence, we aimed to investigate the capability of computed tomography (CT)-based neck nodal radiomics for predicting IfTM-triggered ART events in NPC patients via a multi-center setting. Contrast-enhanced CT and the clinical data of 124 and 58 NPC patients from Queen Elizabeth Hospital (QEH) and Queen Mary Hospital (QMH), respectively, were retrospectively analyzed. Radiomic (R), clinical (C), and combined (RC) models were developed using the ridge algorithm in the QEH cohort and evaluated in the QMH cohort using the median area under the receiver operating characteristics curve (AUC). Delong's test was employed for model comparison. Model performance was further assessed on 1000 replicates in both cohorts separately via bootstrapping. The R model yielded the highest "corrected" AUC of 0.784 (BCa 95%CI: 0.673-0.859) and 0.723 (BCa 95%CI: 0.534-0.859) in the QEH and QMH cohort following bootstrapping, respectively. Delong's test indicated that the R model performed significantly better than the C model in the QMH cohort ( < 0.0001), while demonstrating no significant difference compared to the RC model ( = 0.5773). To conclude, CT-based neck nodal radiomics was capable of predicting IfTM-triggered ART events in NPC patients in this multi-center study, outperforming the traditional clinical model. The findings of this study provide valuable insights for future study into developing an effective screening strategy for ART eligibility in NPC patients in the long run, ultimately alleviating the workload of clinical practitioners, streamlining ART procedural efficiency in clinics, and achieving personalized RT for NPC patients in the future. 10.3390/life12020241