Journal of Radiotherapy in Practice最新文献

{"title":"Effect of tumour involvement on activity determination of resin Yttrium-90 in selective internal radiation therapy of metastatic liver cancer","authors":"Jun Yu Li, Yan Yu, R. Anne","doi":"10.1017/S1460396922000280","DOIUrl":"https://doi.org/10.1017/S1460396922000280","url":null,"abstract":"Abstract Introduction: The study was aimed to evaluate the effect of tumour involvement on resin Yttrium-90 (Y90) activity determination for metastatic liver cancer treatment. Methods: One hundred and two cases of resin Y90 microsphere treatment were retrospectively studied. Body surface area (BSA) method was used in the calculation of resin Y90 activity. The total activity (TA) was calculated as a summation of activities obtained from BSA-based calculation and tumour involvement (TI). TI and TA of each case were evaluated. The contributions of TI to TA were calculated with the ratio of TI/TA. Results: The average contribution of TI to TA was 4·1%. The contributions were < 5·8% in 75% of the cases, < 2·2% in 50% of the cases and < 1·0% in 25% of the cases. Conclusions: Overall the effect of tumour involvement on the activity determination was small. The activity calculation could be simplified by neglecting TI in 25% of the cases where the activity contribution from TI was less than 1%. Contouring tumour and liver structures for TI calculation could be avoided in these cases, and the efficiency of the workflow for resin Y90 procedures could be improved.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42578330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Association of survival with stereotactic body radiation therapy following induction chemotherapy for unresected locally advanced pancreatic cancer.","authors":"Sung Jun Ma,&nbsp;Lucas M Serra,&nbsp;Austin J Bartl,&nbsp;Hye Ri Han,&nbsp;Fatemeh Fekrmandi,&nbsp;Austin J Iovoli,&nbsp;Kavitha M Prezzano,&nbsp;Gregory M Hermann,&nbsp;Han Yu,&nbsp;Anurag K Singh","doi":"10.1017/s1460396921000212","DOIUrl":"https://doi.org/10.1017/s1460396921000212","url":null,"abstract":"<p><strong>Background: </strong>Induction chemotherapy (iC) followed by concurrent chemoradiation has been shown to improve overall survival (OS) for locally advanced pancreatic cancer (LAPC). However, the survival benefit of stereotactic body radiation therapy (SBRT) versus conventionally fractionated radiation therapy (CFRT) following iC remains unclear.</p><p><strong>Methods: </strong>The National Cancer Database (NCDB) was queried for primary stage III, cT4N0-1M0 LAPC (2004-2015). Kaplan-Meier analysis, Cox proportional hazards method, and propensity score matching were used.</p><p><strong>Results: </strong>Among 872 patients, 738 patients underwent CFRT and 134 patients received SBRT. Median follow-up was 24.3 months and 22.9 months for the CFRT and SBRT cohorts, respectively. The use of SBRT showed improved survival in both the multivariate analysis (HR 0.78, p=0.025) and 120 propensity-matched pairs (median OS 18.1 vs 15.9 months, p=0.004) compared to the CFRT.</p><p><strong>Conclusion: </strong>This NCDB analysis suggests survival benefit with the use of SBRT versus CFRT following iC for the LAPC.</p>","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":"21 3","pages":"403-410"},"PeriodicalIF":0.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/s1460396921000212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33438070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adjuvant chemotherapy versus observation following neoadjuvant therapy and surgery for resectable stage I-II pancreatic cancer.","authors":"Sung Jun Ma, Lucas M Serra, Austin J Bartl, Hye Ri Han, Fatemeh Fekrmandi, Austin J Iovoli, Gregory M Hermann, Han Yu, Anurag K Singh","doi":"10.1017/s1460396921000194","DOIUrl":"10.1017/s1460396921000194","url":null,"abstract":"<p><strong>Background: </strong>Neoadjuvant therapy (NT), either with systemic treatment alone or in combination with radiation, is often utilized in the management of pancreatic adenocarcinoma to increase the likelihood of margin-negative resection. Following NT and resection, additional adjuvant chemotherapy (AC) can be considered for select patients and has been shown to improve overall survival (OS). This National Cancer Data Base (NCDB) analysis was performed to evaluate the outcomes of AC versus observation for resected pancreatic adenocarcinoma treated with NT.</p><p><strong>Methods: </strong>The NCDB was queried for primary stage I-II cT1-3N0-1M0 resected pancreatic adenocarcinoma treated with NT (2004-2015). Baseline patient, tumor, and treatment characteristics were extracted. The primary endpoint was OS. With a 6-month conditional landmark, Kaplan-Meier analysis, multivariable Cox proportional hazards method, 1:1 propensity score matching were used to analyze the data.</p><p><strong>Results: </strong>A total of 1737 eligible patients were identified, of which 1247 underwent postoperative observation compared to 490 with AC. The overall median follow-up was 34.7 months. The addition of AC showed improved survival on the multivariate analysis (HR 0.78, p<0.001). Of 490 propensity-matched pairs, all variables were well balanced, including age (p=0.61), Charlson-Deyo comorbidity score (p=0.80), ypT stage (p=0.93), ypN stage (p=0.83), surgical margin (p=0.83), duration of postoperative inpatient admission (p=0.96), and 30-day unplanned readmission after resection (p=0.34). AC remained statistically significant for improved OS, with median OS of 26.3 months vs 22.3 months and 2-year OS of 63.9% vs 52.9% for the observation cohort (p<0.001). Treatment interaction analysis showed OS benefit of AC for patients with smaller tumors (HR 0.67, p<0.001 for <3.1 cm vs HR 0.93, p=0.48 for ≥3.1 cm).</p><p><strong>Conclusion: </strong>Using propensity score matched analysis, our findings suggest a survival benefit for adjuvant chemotherapy compared to observation following NT and surgery for resectable pancreatic adenocarcinoma, especially in patients with smaller tumors. Prospective studies are needed to identify subset of patients that would benefit from adjuvant chemotherapy.</p>","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":"21 3","pages":"383-392"},"PeriodicalIF":0.3,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9398187/pdf/nihms-1698775.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33438069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Systematic self-reporting of patients’ symptoms: improving oncologic care and patients’ satisfaction","authors":"E. Osei, Catherine B. McKenna, J. Darko, Kathy McKnight, Christine Y Peters","doi":"10.1017/S1460396922000255","DOIUrl":"https://doi.org/10.1017/S1460396922000255","url":null,"abstract":"Abstract Background: In recent years, there has been a growing interest to enhance patients’ symptom management during routine cancer care using patient-reported outcome measures. The goal of this study is to analyse patients’ responses to the Edmonton Symptom Assessment System (ESAS) to determine whether patient-reported outcomes could help characterise those patients with the highest supportive care needs and symptom burden in order to help provide targeted support for patients. Methods: In this study, we analysed ESAS questionnaire responses completed by patients as part of their routine care and considered part of patients’ standard of care. Statistical analyses were performed using the IBM SPSS Statistics version 26.0. Descriptive statistics are used to summarise patient demographics, disease characteristics and patient-reported symptom severity and prevalence. Results: The overall mean age is 65.2 ± 12.8 years comprising 43.8% male and 56.2% female patients. The five common primary disease sites are breast (26.2%), haematology (21.1%), gastrointestinal (15.3%), genitourinary (12.7%) and lung (12.0%) cancers. The mean severity for each symptom is all mild (score: 1–3). The three most common reported symptoms causing distress are tiredness, poor overall wellbeing and anxiety, and the least reported symptom is nausea. Conclusions: Systematic self-reporting of patients’ symptoms is important to improve symptom management, timely facilitation of appropriate intervention, patient experience, and patient and family satisfaction. The awareness of disease site, gender and age-related symptom variations should help in the design and provision of appropriate symptom-directed, tumour-specific and patient-focused interventions to meet patients’ immediate needs.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42548947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric effects of oral contrast in the planning of conventional radiotherapy and IMRT, for rectal cancer treatment","authors":"Nadia Montero-Oleas, Andrés Imbaquingo-Cabrera, Alejandro Coloma-Espin, Vladimir Collantes-Cruz, Carlos Molineros, Cristina Núñez-Silva","doi":"10.1017/S1460396922000243","DOIUrl":"https://doi.org/10.1017/S1460396922000243","url":null,"abstract":"Abstract Introduction: Contrast media are frequently used during radiation therapy simulation. However, there are concerns about dosimetric variations when dose calculation is done on contrast-enhanced computed tomography (CT). This study evaluates the dosimetric effect of oral contrast during three-dimensional conformal radiotherapy (3D-CRT) and volumetric modulated arc radiotherapy (VMAT) planning. Methods: Rectal cancer patients were consecutively enrolled. For each patient, one unenhanced CT and one contrast-enhanced CT were taken using oral and intravenous contrast. Then, a 3D-CRT plan and an Intensity-modulated radiation therapy (IMRT)/VMAT plan were generated in the enhanced CT, and the dose distribution was recalculated in the respective unenhanced CT. The beam intensities were kept the same as for the enhanced CT plans. Finally, the unenhanced and enhanced plans were compared by calculating the gamma index. Results: For 3D-CRT plans, there were statistically significant differences in second phase planning target volume (PTV) D2% (Mean difference (MD) between unenhanced and enhanced CT 0·01 Gy, 95% CI [0·003 to 0·02 Gy]) and in maximum doses to the bladder (MD 0·26 Gy, 95% CI [0·05 to 0·47 Gy]). For IMRT/VMAT plans, there were statistically significant differences in small intestine V45 Gy (MD 3·1 cc, 95% CI [0·81 to 5·4 cc]), bladder V45 Gy (MD 2·9%, 95% CI [1·4 to 4·3%]) and maximum dose to the bladder (MD 0·65 Gy, 95% CI [0·46 Gy to 0·85 Gy]). In addition, for PTV D98% the MD between unenhanced and enhanced CT was 0·22 Gy 95% CI [0·05 to 0·39]. Conclusions: For most of the dose metrics, the differences were not clinically meaningful. The greatest differences were found in VMAT plans, especially in V45 Gy of the small intestine. This difference could lead to an underestimation of dose–volume metrics when the plan is based on an enhanced CT. The use of small bowel oral contrast does not significantly influence dose calculations and may not affect the acceptability of plans when adhering to constraints.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42727513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Total body irradiation using volumetric modulated arc therapy, experience of a cancer hospital in Pakistan","authors":"Tabinda Sadaf, A. Rashid, Waqas Imam Bokhari, E. Samuel, A. Shahid, Raheel Mukhtar, Umair Zafar, K. Iqbal","doi":"10.1017/S1460396922000097","DOIUrl":"https://doi.org/10.1017/S1460396922000097","url":null,"abstract":"Abstract Introduction: To report the planning parameters, efficacy and toxicity of total body irradiation using volumetric modulated arc therapy (VMAT). Methods: From July 2019 till May 2021, nine patients treated with VMAT-based total body irradiation as a part of the myeloablative regimen for homologous stem cell transplant were evaluated. The CT acquisition, planning parameters, doses to target volume and critical structures were evaluated retrospectively. Results: Median age was 24 with median height 172 cm. Average Mean Lung dose was 9·5 Gy, mean dose to kidney was kidney dose 8·4 Gy, planning target volume (PTV) 95% was 98 % and mean heterogeneity index of PTV was 1·2 all patients. Total fraction delivery time including setup was 3·1 h while beam on time was 23 min. Main toxicity observed was mucositis and fatigue, while no Grade 3 or more acute radiation toxicity was observed. Conclusion: At our institution, high dose TBI performed with multi-isocentric VMAT is now a standard procedure. Though it is cumbersome and time-consuming process but VMAT offers an advantage of increased dose homogeneity in the target volume with reduction in doses to critical organs especially lungs and kidneys in comparison to standard source to skin distance technique, longer follow-up time is necessary to evaluate our method and long-term toxicity.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42620687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanding access to rectal spacers in the United Kingdom: an examination of current evidence and an early review of data from a single institution","authors":"I. Watts, A. Clifford, S. Needleman, Ashoke Roy, C. Hartill, Alexandra Gore, M. Prentice","doi":"10.1017/S146039692200022X","DOIUrl":"https://doi.org/10.1017/S146039692200022X","url":null,"abstract":"Abstract Background: Prostate cancer is a common malignancy with rising incidence in Western countries such as the United Kingdom. In localised disease there are a variety of curative treatment modalities. Patients can be referred for surgery, or for a combination of hormonal therapies and radiotherapy (external beam radiotherapy or brachytherapy). Each treatment option comes with side effects and in the case of radiotherapy one potential complication is bowel toxicity from radiation exposure. New technologies are being developed to try and mitigate the side effects and long term morbidity of this treatment, and to expand access to radiotherapy for patients who may previously have been excluded (i.e those with inflammatory bowel disease). Rectal Spacers are absorbable polyethylene glycol hydrogels injected into the perirectal space. These position the anterior rectal wall away from the prostate, subsequently minimising radiation dose to the rectum. Rectal Spacers have been introduced to National Healthcare Service (NHS) practice as part of the Innovation and Technology Payment (ITP) programme, however, their use is now under review. Methodology and Results: In this editorial we conduct a narrative review of some of the available evidence for Rectal Spacers, discuss their utilization within the NHS and the barriers to their wider use. We also explore preliminary dosimetry and quality of life data for use of Rectal Spacers in our centre where we have been part of the NHS ITP programme. Dosimetry data and Quality of life questionnaires were gathered from 22 treated patients and 11 matched controls. This indicated lower radiation doses to the prostate in those treated with Rectal Spacers. Conclusion: Rectal Spacers are an effective method to reduce radiation dose to the prostate in men treated for localised prostate cancer, however, their use remains under review in the NHS and there are a variety of barriers to upscaling their use.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48192318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radiographers’ perception on the provision of psychosocial support for cancer patients","authors":"Jade Azzopardi, S. Mercieca, J. L. Portelli","doi":"10.1017/S1460396922000218","DOIUrl":"https://doi.org/10.1017/S1460396922000218","url":null,"abstract":"Abstract Introduction: Therapeutic radiographers are the first point of contact for cancer patients undergoing radiotherapy treatment and therefore have an important role in providing both physical and psychosocial support to these patients. This study aimed to evaluate therapeutic radiographers’ perception about their role in identifying and providing psychosocial support for patients receiving RT treatment. Method: The study used a cross-sectional, prospective research design. A self-designed questionnaire was distributed to all therapeutic radiographers (n = 26) working at a radiotherapy department in Malta. Results: A total of 21 therapeutic radiographers completed the questionnaire. All participants felt that the provision of psychological care was an important part of their role as therapeutic radiographers. The majority of the participants reported having the most confidence in giving treatment-related symptoms advice rather than psychological support. The most common barrier to providing psychological support was lack of training (95·2%), followed by the lack of an appropriate screening tool (85·7%), availability of private space to talk to patients (76·2%) and a lack of knowledge (61·9%). Conclusion: While most therapeutic radiographers believed that providing psychosocial support was an important aspect of their role, several barriers prevented them from fulfilling this role. Training, the introduction of a psychosocial screening tool and clear referral processes are recommended to improve radiotherapy service.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46275844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparing patient acceptability of MR-guided radiotherapy to conventional CBCT on two Elekta systems: a questionnaire-based survey","authors":"L. Whiteside, C. Nelder, E. Pitt, C. Hodgson, A. Choudhury, C. Eccles","doi":"10.1017/S1460396922000206","DOIUrl":"https://doi.org/10.1017/S1460396922000206","url":null,"abstract":"Abstract Background and Purpose: The magnetic resonance linear accelerator system (MR Linac) is a novel piece of radiotherapy (RT) equipment allowing the routine application of daily MR-guided treatment adaptation. The hardware design required for such technical capabilities and the increased complexity of the treatment workflow entails a notable departure from cone beam computed tomography (CBCT)-based RT. Patient tolerability of treatment is paramount to RT practice where high compliance is required. Presented is a comparative analysis of how such modality specific characteristics may ultimately impact the patient experience of treatment. Materials and Methods: Forty patients undergoing RT for prostate cancer (PCa) on either the MR Linac (n = 20) or a CBCT-based linac (n = 20) were provided with a validated patient reported outcomes measures (PROM’s) questionnaire at fraction 1 and fraction 20. The 18-item questionnaire provided patient responses recorded using a 4-point Likert scale, 0 denoting a response of ‘Not at all’, 1 ‘Slightly’, 2 ‘Moderately’ and 3 signifying ‘Very’. The analysis provided insight into both comparisons between modalities at singular time points (fractions 1 and 20), as well as a temporal analysis within a single modality, denoting changing patient experience. Results: Patients generally found the MR Linac treatment couch more comfortable, however, found the increase in treatment duration harder to tolerate. Responses for all items remained stable between first and last fraction across both cohorts, indicating minimal temporal variation within a single modality. None of the responses were statistically significant at the 0·01 level. Conclusion: Whether radiotherapy for PCa is delivered on a CBCT linac or the MR Linac, there is little difference in patient experience with minimal experiential variation within a single modality.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44351740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric effect of modelling non-homogeneous LINAC couch using cone-beam computed tomography on quality assurance (QA) results","authors":"A. Banaei, Mohsen Bakhshandeh, Mohammad Rasa Golrokh-Nodehi","doi":"10.1017/S1460396921000716","DOIUrl":"https://doi.org/10.1017/S1460396921000716","url":null,"abstract":"Abstract Aim: To evaluate the dosimetric effect of modelling a non-homogeneous couch on patients’ quality assurance (QA) gamma pass rates for intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques. Materials and Methods: A non-homogeneous treatment couch (TxT 550 TTM, CIVCO, USA) was imaged using the LINAC mounted cone-beam computer tomography (CBCT) system. Modelling this couch in different situations, including incomplete (homogeneous model), correct model and not defined situations in the treatment planning system (TPS), was performed based on the geometrical and material densities data extracted from the CBCT images. Calculated gamma pass rates between TPS dose calculations and the measurements in a phantom for different couch models were obtained and compared at two gamma criteria (2%-2 mm and 3%-3 mm). Results: Comparing TPS calculations for the correct modelled couch and the measurements showed high gamma pass rates for both the IMRT and VMAT techniques (96·5 ± 0·9%, 99·2 ± 0·5% for IMRT in 2%-2 mm and 3%-3 mm criteria; 97·5 ± 0·8%, 99·4 ± 0·5% for VMAT). The overall gamma pass rate of the IMRT plan QAs was reduced by about 2% and 3% on average for incomplete and no couch modelling, respectively. These reductions for VMAT techniques were 2·5% and 4·3%, respectively. Conclusions: Non-homogeneous couches have different parts with different attenuations, which can be correctly defined using LINAC CBCT. Modelling of treatment couch has a significant effect on patient QA results for VMAT and IMRT plans, especially in radiation fields/subfield transmitting from the couch. We suggest using LINAC CBCTs as an appropriate device for couch modelling in modulated radiotherapy techniques.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":" ","pages":""},"PeriodicalIF":0.4,"publicationDate":"2022-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47507250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}