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Chen R, Xie J, Chen J, Li X, Lin Q, Xu Q, Chen Y, Wang L, Zheng R, Xu B. Analysis of the Parotid Glands on an Energy Spectrum CT Iodine Map to Evaluate Irradiation-Induced Acute Xerostomia in Patients With Nasopharyngeal Carcinoma. Technol Cancer Res Treat 2024; 23:15330338241256814. [PMID: 38773777 PMCID: PMC11113032 DOI: 10.1177/15330338241256814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 04/15/2024] [Accepted: 05/02/2024] [Indexed: 05/24/2024] Open
Abstract
Objective: This prospective study aims to evaluate acute irradiation-induced xerostomia during radiotherapy by utilizing the normalized iodine concentration (NIC) derived from energy spectrum computed tomography (CT) iodine maps. Methods: In this prospective study, we evaluated 28 patients diagnosed with nasopharyngeal carcinoma. At 4 distinct stages of radiotherapy (0, 10, 20, and 30 fractions), each patient underwent CT scans to generate iodine maps. The NIC of both the left and right parotid glands was obtained, with the NIC at the 0-fraction stage serving as the baseline measurement. After statistically comparing the NIC obtained in the arterial phase, early venous phase, late venous phase, and delayed phase, we chose the late venous iodine concentration as the NIC and proceeded to analyze the variations in NIC at each radiotherapy interval. Using the series of NIC values, we conducted hypothesis tests to evaluate the extent of change in NIC within the parotid gland across different stages. Furthermore, we identified the specific time point at which the NIC decay exhibited the most statistically significant results. In addition, we evaluated the xerostomia grades of the patients at these 4 stages, following the radiation therapy oncology group (RTOG) xerostomia evaluation standard, to draw comparisons with the changes observed in NIC. Results: The NIC in the late venous phase exhibited the highest level of statistical significance (P < .001). There was a noticeable attenuation in NIC as the RTOG dry mouth grade increased. Particularly, at the 20 fraction, the NIC experienced the most substantial attenuation (P < .001), a significant negative correlation was observed between the NIC of the left, right, and both parotid glands, and the RTOG evaluation grade of acute irradiation-induced xerostomia (P < .001, r = -0.46; P < .001, r = -0.45; P < .001, r = -0.47). The critical NIC values for the left, right, and both parotid glands when acute xerostomia occurred were 0.175, 0.185, and 0.345 mg/ml, respectively, with AUC = 0.73, AUC = 0.75, and AUC = 0.75. Conclusion: The NIC may be used to evaluate changes in parotid gland function during radiotherapy and acute irradiation-induced xerostomia.
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Affiliation(s)
- Runfan Chen
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
- School of Medical Imaging, Fujian Medical University, Fuzhou, China
| | - Jiangao Xie
- Department of Radiology, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
| | - Jianmin Chen
- Department of Statistics, University of Connecticut, Storrs, USA
| | - Xiaobo Li
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
- School of Medical Imaging, Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Intelligent Imaging and Precision Radiotherapy for Tumours (Fujian Medical University), Fuzhou, China
- Clinical Research Center for Radiology and Radiotherapy of Fujian Province (Digestive, Haematological and Breast Malignancies), Fuzhou, China
| | - Qingliang Lin
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
| | - Qizhen Xu
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
| | - Yanyan Chen
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
| | - Lili Wang
- Department of Radiology, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
| | - Rong Zheng
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Intelligent Imaging and Precision Radiotherapy for Tumours (Fujian Medical University), Fuzhou, China
- Clinical Research Center for Radiology and Radiotherapy of Fujian Province (Digestive, Haematological and Breast Malignancies), Fuzhou, China
| | - Benhua Xu
- Department of Radiotherapy, Union Hospital Affiliated to Fujian Medical University, Fuzhou, China
- Fujian Key Laboratory of Intelligent Imaging and Precision Radiotherapy for Tumours (Fujian Medical University), Fuzhou, China
- Clinical Research Center for Radiology and Radiotherapy of Fujian Province (Digestive, Haematological and Breast Malignancies), Fuzhou, China
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Meng L, Teng F, Liu Q, Du L, Cai B, Xie C, Gong H, Zhang X, Ma L. Long-term outcomes of nasopharyngeal carcinoma treated with helical tomotherapy using simultaneous integrated boost technique: A 10-year result. Front Oncol 2023; 12:1083440. [PMID: 36741709 PMCID: PMC9896002 DOI: 10.3389/fonc.2022.1083440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 12/28/2022] [Indexed: 01/22/2023] Open
Abstract
Background To evaluate the long-term survival and treatment-related toxicities of helical tomotherapy (HT) in nasopharyngeal carcinoma (NPC) patients. Methods One hundred and ninety newly diagnosed non-metastatic NPC patients treated with HT from September 2007 to August 2012 were analyzed retrospectively. The dose at D95 prescribed was 70-74Gy, 60-62.7Gy and 52-56Gy delivered in 33 fractions to the primary gross tumor volume (pGTVnx) and positive lymph nodes (pGTVnd), the high risk planning target volume (PTV1), and the low risk planning target volume (PTV2), respectively, using simultaneous integrated boost technique. The statistical analyses were performed and late toxicities were evaluated and scored according to the Common Terminology Criteria for Adverse Events (version 3.0). Results The median follow-up time was 145 months. The 10-year local relapse-free survival (LRFS), nodal relapse-free survival (NRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were 94%, 95%, 86%, and 77.8%; respectively. Fifty (26.3%) patients had treatment-related failures at the last follow-up visit. Distant metastasis, occurred in 25 patients, was the major failure pattern. Multivariate analysis showed that age and T stage were independent predictors of DMFS and OS, Concomitant chemotherapy improved overall survival, but anti-EGFR monoclonal antibody therapy failed. The most common late toxicities were mainly graded as 1 or 2. Conclusions Helical tomotherapy with simultaneous integrated boost technique offered excellent long-term outcomes for NPC patients, with mild late treatment-related toxicities. Age and clinical stage were independent predictors of DMFS and OS. And, concurrent chemotherapy means better OS. Further prospective study is needed to confirm the superiority of this technology and to evaluate the roles of anti-EGFR monoclonal antibody treatment.
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Affiliation(s)
- Lingling Meng
- Medical School of the Chinese People’s Liberation Army (PLA), Beijing, China,Department of Radiation Oncology, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Feng Teng
- Department of Radiation Oncology, China-Japan Friendship Hospital, Beijing, China
| | - Qiteng Liu
- Department of Radiation Oncology, Beijing Luhe Hospital, Affiliated to Capital Medical University, Beijing, China
| | - Lei Du
- Department of Radiation Oncology, Hainan Hospital of the Chinese PLA General Hospital, Sanya, China
| | - Boning Cai
- Department of Radiation Oncology, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Chuanbin Xie
- Department of Radiation Oncology, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Hanshun Gong
- Department of Radiation Oncology, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Xinxin Zhang
- Department of Otorhinolaryngology, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Lin Ma
- Medical School of the Chinese People’s Liberation Army (PLA), Beijing, China,Department of Radiation Oncology, First Medical Center of Chinese PLA General Hospital, Beijing, China,*Correspondence: Lin Ma,
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Parotid Gland Stem Cell Preservation during Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma: Dosimetric Analysis and Feasibility. JOURNAL OF ONCOLOGY 2022; 2022:4922409. [PMID: 35865088 PMCID: PMC9296294 DOI: 10.1155/2022/4922409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 11/18/2022]
Abstract
Objective. Parotid gland (PG) is a radiosensitive organ, and xerostomia (XS) is a key factor affecting patients’ life quality after conventional radiotherapy for head and neck tumors. In this study, dosimetry analysis was performed on PG stem cell preservation in intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods. All clinical data of 80 NPC patients diagnosed pathologically in the Radiotherapy Department of Taizhou Hospital of Zhejiang Province Affiliated with Wenzhou Medical University from August 2017 to September 2019 were retrospectively analyzed. Patients were assigned to a regular group and a restricted group according to different IMRT plans, in which a dose limitation for the parotid duct was added in the restricted group in addition to the conventional plan used in the regular group to minimize the parotid duct radiation dose. The differences in planning target volume (PTV) dose distribution, organ at risk (OAR) dose, and dose to the PG and its ducts were compared between the two groups. Results. Significantly higher mean irradiation doses of the brainstem, mandible, and oral cavity were determined in the restricted group compared with the regular group (
), but there was no significant difference in the mean dose of other OARs irradiated (
). As compared to the irradiation of bilateral PGs, no statistical differences were found in the mean irradiation dose and V30 between regular and restricted groups (
), but lower V20 and higher V45 were determined in the restricted group (
). The mean irradiation dose, V15, V20, and V26 of bilateral parotid ducts were lower in the restricted group as compared to the regular group (
). Conclusion. IMRT for NPC can effectively reduce the mean irradiation dose and play a PG stem cell preservation role by giving specific dose limitation conditions to the parotid duct area without affecting PTV dose distribution and OAR irradiation dose, which has certain feasibility.
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Evaluation and risk factors of volume and dose differences of selected structures in patients with head and neck cancer treated on Helical TomoTherapy by using Deformable Image Registration tool. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2022. [DOI: 10.2478/pjmpe-2022-0007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract
Introduction: The aim of this study was the evaluation of volume and dose differences in selected structures in patients with head and neck cancer during treatment on Helical TomoTherapy (HT) using a commercially available deformable image registration (DIR) tool. We attempted to identify anatomical and clinical predictive factors for significant volume changes probability.
Material and methods: According to our institutional protocol, we retrospectively evaluated the group of 20 H&N cancer patients treated with HT who received Adaptive Radiotherapy (ART) due to soft tissue alterations spotted on daily MVCT. We compared volumes on initial computed tomography (iCT) and replanning computed tomography (rCT) for clinical target volumes (CTV) – CTV1 (the primary tumor) and CTV2 (metastatic lymph nodes), parotid glands (PG) and body contour (B-body). To estimate the planned and delivered dose discrepancy, the dose from the original plan was registered and deformed to create a simulation of dose distribution on rCT (DIR-rCT).
Results: The decision to replan was made at the 4th week of RT (N = 6; 30%). The average volume reduction in parotid right PG[R] and left PG[L] was 4.37 cc (18.9%) (p < 0.001) and 3.77 cc (16.8%) (p = 0.004), respectively. In N = 13/20 cases, the delivered dose was greater than the planned dose for PG[R] of mean 3 Gy (p < 0.001), and in N = 6/20 patients for PG[L] the mean of 3.6 Gy (p = 0.031). Multivariate regression analysis showed a very strong predictor explaining 88% (R2 = 0.88) and 83% (R2 = 0.83) of the variance based on the mean dose of iPG[R] and iPG[L] (p < 0.001), respectively. No statistically significant correlation between volume changes and risk factors was found.
Conclusions: Dosimetric changes to the target demonstrated the validity of replanning. A DIR tool can be successfully used for dose deformation and ART qualification, significantly reducing the workload of radiotherapy centers. In addition, the mean dose for PG was a significant predictor that may indicate the need for a replan.
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Bak B, Skrobala A, Adamska A, Kazmierska J, Jozefacka N, Piotrowski T, Malicki J. Criteria for Verification and Replanning Based on the Adaptive Radiotherapy Protocol "Best for Adaptive Radiotherapy" in Head and Neck Cancer. Life (Basel) 2022; 12:722. [PMID: 35629389 PMCID: PMC9144703 DOI: 10.3390/life12050722] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 11/17/2022] Open
Abstract
No clear criteria have yet been established to guide decision-making for patient selection and the optimal timing of adaptive radiotherapy (ART) based on image-guided radiotherapy (IGRT). We have developed a novel protocol—the Best for Adaptive Radiotherapy (B-ART) protocol—to guide patient selection for ART. The aim of the present study is to describe this protocol, to evaluate its validity in patients with head and neck (HN) cancer, and to identify the anatomical and clinical predictors of the need for replanning. We retrospectively evaluated 82 patients with HN cancer who underwent helical tomotherapy (HT) and subsequently required replanning due to soft tissue changes upon daily MVCT. Under the proposed criteria, patients with anatomical changes >3 mm on three to four consecutive scans are candidates for ART. We compared the volumes on the initial CT scan (iCT) and the replanning CT (rCT) scan for the clinical target volumes (CTV1, referring to primary tumor or tumor bed and CTV2, metastatic lymph nodes) and for the parotid glands (PG) and body contour (B-body). The patients were stratified by primary tumor localization, clinical stage, and treatment scheme. The main reasons for replanning were: (1) a planning target volume (PTV) outside the body contour (n = 70; 85.4%), (2) PG shrinkage (n = 69; 84.1%), (3) B-body deviations (n = 69; 84.1%), and (4) setup deviations (n = 40; 48.8%). The replanning decision was made, on average, during the fourth week of treatment (n = 47; 57.3%). The mean reductions in the size of the right and left PG volumes were 6.31 cc (20.9%) and 5.98 cc (20.5%), respectively (p < 0.001). The reduction in PG volume was ≥30% in 30 patients (36.6%). The volume reduction in all of the anatomical structures was statistically significant. Four variables—advanced stage disease (T3−T4), chemoradiation, increased weight loss, and oropharyngeal localization—were significantly associated with the need for ART. The B-ART protocol provides clear criteria to eliminate random errors, and to allow for an early response to relevant changes in target volumes.
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Affiliation(s)
- Bartosz Bak
- Department of Electroradiology, Poznan University of Medical Science, 61-866 Poznan, Poland; (A.S.); (J.K.); (T.P.); (J.M.)
- Department of Radiotherapy II, Greater Poland Cancer Centre, 61-866 Poznan, Poland
| | - Agnieszka Skrobala
- Department of Electroradiology, Poznan University of Medical Science, 61-866 Poznan, Poland; (A.S.); (J.K.); (T.P.); (J.M.)
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland
| | - Anna Adamska
- Department and Radiotherapy Ward I, Greater Poland Cancer Centre, 61-866 Poznan, Poland;
| | - Joanna Kazmierska
- Department of Electroradiology, Poznan University of Medical Science, 61-866 Poznan, Poland; (A.S.); (J.K.); (T.P.); (J.M.)
- Department of Radiotherapy II, Greater Poland Cancer Centre, 61-866 Poznan, Poland
| | - Natalia Jozefacka
- Institute of Psychology, Pedagogical University in Krakow, 30-084 Krakow, Poland;
| | - Tomasz Piotrowski
- Department of Electroradiology, Poznan University of Medical Science, 61-866 Poznan, Poland; (A.S.); (J.K.); (T.P.); (J.M.)
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland
| | - Julian Malicki
- Department of Electroradiology, Poznan University of Medical Science, 61-866 Poznan, Poland; (A.S.); (J.K.); (T.P.); (J.M.)
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland
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Bak B, Skrobala A, Adamska A, Malicki J. What information can we gain from performing adaptive radiotherapy of head and neck cancer patients from the past 10 years? Cancer Radiother 2021; 26:502-516. [PMID: 34772603 DOI: 10.1016/j.canrad.2021.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/06/2021] [Accepted: 08/12/2021] [Indexed: 01/10/2023]
Abstract
The aim of the review was to present the current literature status about replanning regarding anatomical and dosimetric changes in the target and OARs in the head and neck region during radiotherapy, to discuss and to analyze factors influencing the decision for adaptive radiotherapy of head and neck cancer patients. Significant progress has been made in head and neck patients' evaluation and qualification for adapted radiotherapy over the past ten years. Many factors leading to anatomical and dosimetric changes during treatment have been identified. Based on the literature, the most common factors triggering re-plan are weight loss, tumor and nodal changes, and parotid glands shrinkage. The fluctuations in dose distribution in the clinical area are significant predictive factors for patients' quality of life and the possibility of recovery. It has been shown that re-planning influence clinical outcomes: local control, disease free survival and overall survival. Regarding literature studies, it seems that adaptive radiotherapy would be the most beneficial for tumors of immense volume or those in the nearest proximity of the OARs. All researchers agree that the timing of re-planning is a crucial challenge, and there are still no clear consensus guidelines for time or criteria of re-planning. Nowadays, thanks to significant technological progress, the decision is mostly made based on observation and supported with IGRT verification. Although further research is still needed, adaptive strategies are evolving and now became the state of the art of modern radiotherapy.
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Affiliation(s)
- B Bak
- Radiotherapy Department II, Greater Poland Cancer Center, Poznan, Poland; Department of Electroradiology, University of Medical Science, Poznan, Poland.
| | - A Skrobala
- Department of Electroradiology, University of Medical Science, Poznan, Poland; Department of Medical Physics, Greater Poland Cancer Center, Poznan, Poland
| | - A Adamska
- Radiotherapy Ward I and Department I, Greater Poland Cancer Center, Poznan, Poland
| | - J Malicki
- Department of Electroradiology, University of Medical Science, Poznan, Poland
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Radaideh KM. Dosimetric impact of weight loss and anatomical changes at organs at risk during intensity-modulated radiotherapy for head-and-neck cancer. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2020. [DOI: 10.1080/16878507.2020.1731125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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O'Toole J, Wu K, Bromley R, Stevens M, Eade T, van Gysen K, Atyeo J. Parotid sparing in RapidPlan Oropharynx models: To split or not to split. J Med Radiat Sci 2020; 67:80-86. [PMID: 32043819 PMCID: PMC7063248 DOI: 10.1002/jmrs.376] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 11/19/2019] [Accepted: 12/12/2019] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION Differences in knowledge and experience, patient anatomy and tumour location and manipulation of inverse planning objectives and priorities will lead to a variability in the quality of radiation planning. The aim of this study was to investigate whether parotid glands should be treated as separate or combined structures when using knowledge-based planning (KBP) to create oropharyngeal plans, based on the dose they receive. METHOD Two separate RapidPlan (RP) models were created using the same 70 radical oropharyngeal patients. The 'separated model' divided the parotids into ipsilateral and contralateral structures. The 'combined model' did not separate the parotids. The models were independently validated using 20 patients not included in the models. The same dose constraints and priorities were applied to planning target volumes (PTVs) and organs at risk (OARs) for all plans. An auto-generated line objective and priority was applied in both models, with parotid mean dose and V50 doses evaluated and compared. RESULTS Plans optimised using the combined model resulted in lower ipsilateral mean doses and lower V50 doses in 80% and 75% of cases, respectively. Fifty-five per cent of plans produced lower mean doses for the contralateral parotid when optimised using the combined model, while lower V50 doses were evenly split between the models. CONCLUSION Combining the data for both parotids into one RP model resulted in better ipsilateral parotid sparing. Results also suggest that a combined parotid model will spare dose to the contralateral parotid; however, further investigation is required to confirm these results.
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Affiliation(s)
- James O'Toole
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
| | - Kenny Wu
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
| | - Regina Bromley
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
| | - Mark Stevens
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
| | - Thomas Eade
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
| | - Kirsten van Gysen
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
| | - John Atyeo
- Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Reserve Road, St Leonards, NSW, Australia
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Reducing Xerostomia by Comprehensive Protection of Salivary Glands in Intensity-Modulated Radiation Therapy with Helical Tomotherapy Technique for Head-and-Neck Cancer Patients: A Prospective Observational Study. BIOMED RESEARCH INTERNATIONAL 2019; 2019:2401743. [PMID: 31380414 PMCID: PMC6662416 DOI: 10.1155/2019/2401743] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/09/2019] [Accepted: 06/19/2019] [Indexed: 12/11/2022]
Abstract
Objective This study aimed to analyze the effects of comprehensive protection of bilateral parotid glands (PG-T), contralateral submandibular gland (cSMG), and accessory salivary glands in the oral cavity (OC) by helical tomotherapy for head-and-neck cancer patients. Methods Totally 175 patients with histologically confirmed head-and-neck cancer treated with helical tomotherapy were recruited. The doses delivered to PG-T, cSMG, and OC were constrained to be as low as possible in treatment planning. The saliva flow rates and xerostomia questionnaire were evaluated. Correlation between xerostomia and other clinical factors were assessed using univariate and multivariate models. The impact of salivary gland dose on locoregional (LR) recurrence was assessed by Cox analysis. ROC curve was used to determine the threshold of mean dose for each gland. Results The median follow-up was 25 (19-36) months. The OC mean dose, PG-T mean dose, cSMG mean dose, age, clinical stage (II and III versus IV), and both unstimulated and stimulated saliva flow rates were significantly correlated with xerostomia. The OC mean dose, cSMG mean dose, age, and clinical stage were predictors of xerostomia after adjusting PG-T mean dose, and unstimulated and stimulated saliva flow rates. Xerostomia was significantly decreased when the mean doses of PG-T, cSMG, and OC were kept below 29.12Gy, 29.29Gy, and 31.44Gy, respectively. At 18 months after radiation therapy, early LR recurrence rate was only 4%. Conclusion Comprehensive protection of salivary glands minimized xerostomia in head-and-neck cancer patients treated by helical tomotherapy, without increasing early LR recurrence risk.
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Effect of Changing Phantom Thickness on Helical Radiotherapy Plan: Dosimetric Analysis. POLISH JOURNAL OF MEDICAL PHYSICS AND ENGINEERING 2019. [DOI: 10.2478/pjmpe-2019-0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Purpose: The aim of this study is to investigate the effect of changing phantom thickness on high dose region of interest (HD_ROI) and low dose ROI’s (LW_ROI’s) doses during helical radiotherapy (RT) by utilizing Adaptive RT (ART) technique.
Materials and Methods: The cylindrical phantom (CP) is wrapped with different thickness boluses and scanned in the kilovoltage computed tomography (KVCT). HD_ROI and LW_ROI’s were created in contouring system and nine same plans (1.8 Gy/Fr) were made with images of different thicknesses CP. The point dose measurements were performed using ionization chamber in Helical Tomotherapy (HT) treatment machine. For detecting thickness reduction effect, CP was irradiated using bolus-designed plans and it was irradiated using without bolus plan. The opposite of this scenario was applied to determine the thickness increase. KVCT and megavoltage CT (MVCT) images were used for dose comparison. The HT Planned Adaptive Software was used to see the differences in the planning and verification doses at dose volume histograms (DVH).
Results: Point dose measurements showed a 4.480% dose increase in 0.5 cm depth reduction for HD_ROI. These differences reached 8.508% in 2 cm depth and 15,279% in 5 cm depth. At the same time, a dose reduction of 0.665% was determined for a 0.5cm depth increase, a dose reduction of 1.771% was determined for a 2 cm depth increase, a dose reduction of 5.202% was determined for a 5 cm depth increase for the HD_ROI. The ART plan results show that the dose changes in the HD_ROI was greater than the LW_ROI’s.
Conclusion: Phantom thicknesses change can lead to a serious dose increase or decrease in the HD_ROI and LW_ROI’s.
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Gai X, Wei Y, Tao H, Zhu J, Li B. Clinical study of the time of repeated computed tomography and replanning for patients with nasopharyngeal carcinoma. Oncotarget 2017; 8:27529-27540. [PMID: 28404877 PMCID: PMC5432355 DOI: 10.18632/oncotarget.16770] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 03/09/2017] [Indexed: 11/25/2022] Open
Abstract
PURPOSE To study the necessity of repeat computed tomography (CT) scan and replanning and know a more accurate time using weekly kilovoltage cone beam computed tomography (kV-CBCT) scans for patients with nasopharyngeal carcinoma (NPC) during radiotherapy. METHODS AND MATERIALS Thirteen NPC patients treated with IMRT were enrolled into this prospective study. Weekly pretreatment kV-CBCT scans were performed on the 1st, 6th, 11st, 16th, 21st and 26th radiation time, respectively. Target delineations were contoured on all fractionated CBCT images, including the gross tumor volume of the primary nasopharyngeal tumor (GTVnx) and parotid glands. The volumes of GTVnx and parotid glands were calculated automatically using the Pinnacle3 8.0 system. Compared to the original GTVnx, the percentage of shrinking volume (ΔP) ≥ 50% was considered significantly. RESULTS As the radiation proceeding, the GTVnx had a trend of shrinkage. Of all 13 patients, 11 cases (84.6%) had the volume shrinking ≥ 50% before the 21st radiation and 12 cases (92.3%) before the 26th radiation. And the parotid volume decreased significantly in the first four-week radiation, 6.45 ± 3.16cm3 (range, 3.06-13.9cm3) for the left parotid gland and 5.78 ± 2.39cm3 (range, 2.70-11.2cm3) for the right. Furthermore, only a little displacement occurred to bilateral parotid glands. CONCLUSION The replanning for NPC patients with IMRT is necessary, and the time between the 21st to 25th radiations is appropriate.
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Affiliation(s)
- Xiujuan Gai
- School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Shandong, China.,Department of Radiation Oncology VI, Shandong Cancer Hospital Affiliated to Shandong University, Jinon, Shandong, China
| | - Yumei Wei
- Department of Radiation Oncology VI, Shandong Cancer Hospital Affiliated to Shandong University, Jinon, Shandong, China
| | - Hengmin Tao
- Shandong Provincial Hospital affiliated to Shandong University, Shandong, China.,Shandong Provincial Western Hospital, Shandong, China
| | - Jian Zhu
- Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong, China
| | - Baosheng Li
- Department of Radiation Oncology VI, Shandong Cancer Hospital Affiliated to Shandong University, Jinon, Shandong, China
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12
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Zhang Y, Lin C, Wu J, Jiang X, Lee SWY, Tam SY, Wu VWC. A longitudinal evaluation of early anatomical changes of parotid gland in intensity modulated radiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space involvement. J Med Radiat Sci 2017; 64:188-194. [PMID: 28258633 PMCID: PMC5587653 DOI: 10.1002/jmrs.209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 09/14/2016] [Accepted: 10/31/2016] [Indexed: 11/14/2022] Open
Abstract
Introduction Radiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space (PPS) involvement may deliver high dose to the parotid gland. This study evaluated parotid gland changes during and up to 3 months after radiotherapy. Methods Kilovoltage computed tomography (CT) scans of head and neck region of 39 nasopharyngeal carcinoma patients with PPS involvement were performed at pre‐radiotherapy, 10th, 20th and 30th fractions and 3 months after treatment. The parotid glands were contoured in pre‐radiotherapy planning CT scan and in subsequent scans. Dice similarity coefficient (DSC), percentage volume change and centroid movement between the planning CT and the subsequent CTs were obtained from the contouring software. In addition, the distance between medial and lateral borders of parotid glands from the mid‐line at various time intervals were also measured. Results The ipsilateral parotid gland received a mean dose of about 5 Gy higher than the contralateral side. The mean DSC and parotid volume decreased by more than 30% at 20th fraction and reached the minimum at 30th fraction. Partial recovery was observed at 3 months after treatment. The centroid displacement followed a similar pattern, which moved medially and superiorly by an average of 0.30 cm and 0.18 cm, respectively, at 30th fraction. The changes in ipsilateral gland were slightly greater than the contralateral side. Conclusions Substantial volume change and medial movement of parotid gland were observed with slightly greater magnitude in the ipsilateral side. Adaptive radiotherapy was suggested at around 15th to 20th fraction so as to optimise the original dose distribution of the plan.
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Affiliation(s)
- Yingting Zhang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Chengguang Lin
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Jianhua Wu
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Xiaobo Jiang
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China
| | - Shara W Y Lee
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Shing-Yau Tam
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Vincent W C Wu
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong SAR, China
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13
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Hou WH, Wang CW, Tsai CL, Hsu FM, Cheng JCH. The ratio of weight loss to planning target volume significantly impacts setup errors in nasopharyngeal cancer patients undergoing helical tomotherapy with daily megavoltage computed tomography. Radiol Oncol 2016; 50:427-432. [PMID: 27904451 PMCID: PMC5120582 DOI: 10.1515/raon-2016-0047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 07/19/2016] [Indexed: 11/30/2022] Open
Abstract
Background Changes in head and neck anatomy during radiation therapy (RT) produce setup uncertainties of nasopharyngeal cancer (NPC) irradiation. We retrospectively analyzed image guidance data to identify clinical predictors of setup errors. Patients and methods The data of 217 NPC patients undergoing definitive RT on a helical tomotherapy (HT) unit were analyzed. Factors including tumor stage, body mass index, weight loss, and planning target volume (PTV) were assessed as predictors of daily megavoltage computed tomography (MVCT) setup displacements, which were automatically registered using software. Results Mean daily setup displacements (in mm) were 1.2 ± 0.6, 1.8 ± 0.8, 3.4 ± 1.4 in the medial-lateral (ML), superior-inferior (SI), and anterior-posterior (AP) directions, respectively. Mean weight loss was 4.6 ± 3.3 kg (6.8 ± 4.9%). Patients with weight loss > 5% had significantly larger setup displacements in the AP (3.6 ± 1.5 vs. 2.9 ± 1.1 mm, p < 0.001) and SI (1.6 ± 0.7 vs. 1.9 ± 0.9 mm, p = 0.01) direction, but not in the ML direction (p = 0.279). The AP setup error increased 0.06 mm (y = 0.055x + 2.927, x: percentage of weight loss/PTV, y: AP displacement) per one percent increase in weight loss normalized to PTV. Conclusions Patients with weight loss > 5% and smaller PTVs, possibly because of small body frame or neck girth, were more likely to have increased setup errors in the AP direction.
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Affiliation(s)
- Wei-Hsien Hou
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California, United States of America
| | - Chun-Wei Wang
- Division of Radiation Oncology, Departments of Oncology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan, Province of China
| | - Chiao-Ling Tsai
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California, United States of America
| | - Feng-Ming Hsu
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California, United States of America
| | - Jason Chia-Hsien Cheng
- Division of Radiation Oncology, Departments of Oncology, National Taiwan University College of Medicine and Hospital, Taipei, Taiwan, Province of China; Graduate Institutes of Oncology, National Taiwan University College of Medicine, Taipei, Taiwan, Province of China; Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan, Province of China
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Replanning Criteria and Timing Definition for Parotid Protection-Based Adaptive Radiation Therapy in Nasopharyngeal Carcinoma. BIOMED RESEARCH INTERNATIONAL 2015; 2015:476383. [PMID: 26793717 PMCID: PMC4697077 DOI: 10.1155/2015/476383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/26/2015] [Accepted: 11/30/2015] [Indexed: 11/30/2022]
Abstract
The goal of this study was to evaluate real-time volumetric and dosimetric changes of the parotid gland so as to determine replanning criteria and timing for parotid protection-based adaptive radiation therapy in nasopharyngeal carcinoma. Fifty NPC patients were treated with helical tomotherapy; volumetric and dosimetric (Dmean, V1, and D50) changes of the parotid gland at the 1st, 6th, 11th, 16th, 21st, 26th, 31st, and 33rd fractions were evaluated. The clinical parameters affecting these changes were studied by analyses of variance methods for repeated measures. Factors influencing the actual parotid dose were analyzed by a multivariate logistic regression model. The cut-off values predicting parotid overdose were developed from receiver operating characteristic curves and judged by combining them with a diagnostic test consistency check. The median absolute value and percentage of parotid volume reduction were 19.51 cm3 and 35%, respectively. The interweekly parotid volume varied significantly (p < 0.05). The parotid Dmean, V1, and D50 increased by 22.13%, 39.42%, and 48.45%, respectively. The actual parotid dose increased by an average of 11.38% at the end of radiation therapy. Initial parotid volume, initial parotid Dmean, and weight loss rate are valuable indicators for parotid protection-based replanning.
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