Pub Date : 2024-01-11DOI: 10.1017/S1460396923000444
Sathiya Raj, Venugopal Sundaram, H. Godson, Retna John
Abstract Purpose: This study aimed to investigate the influence of calibration field size on the gamma passing rate (GPR) in patient-specific quality assurance (PSQA). Methods: Two independent detectors, PTW OCTAVIUS 4D (4DOCT) and Arc Check, were utilised in volumetric modulated arc therapy plans for 26 patients (14 with Arc Check and 12 with 4DOCT). Plans were administered using Varian Unique machine (with 4DOCT) and Varian TrueBeam (with Arc Check), each employing different calibration factors (CFs): 4 × 4, 6 × 6, 8 × 8, 10 × 10, 12 × 12 and 15 × 15 cm2 field sizes. Gamma analysis was conducted with 2%2mm, 2%3mm and 3%3mm gamma criteria. Results: GPR exhibited variations across different CFs. GPR demonstrated an increasing trend below 10 × 10 cm² CFs, while it displayed a decreasing trend above 10 × 10 cm². Both detectors exhibited similar GPR patterns. The correlation between 4DOCT and Arc Check was strong in tighter criteria (2%2mm) with an R² value of 0·9957, moderate criteria (2%3mm) with an R² value of 0·9868, but reduced in liberal criteria (3%3mm) with an R² value of 0·4226. Conclusion: This study demonstrates that calibration field sizes significantly influence GPR in PSQA. This study recommends the plan specific calibration field must obtain to calibrate the QA devices for modulated plans.
{"title":"Wobbling nature of gamma passing rate as a function of calibration field sizes in patient-specific quality assurance","authors":"Sathiya Raj, Venugopal Sundaram, H. Godson, Retna John","doi":"10.1017/S1460396923000444","DOIUrl":"https://doi.org/10.1017/S1460396923000444","url":null,"abstract":"Abstract Purpose: This study aimed to investigate the influence of calibration field size on the gamma passing rate (GPR) in patient-specific quality assurance (PSQA). Methods: Two independent detectors, PTW OCTAVIUS 4D (4DOCT) and Arc Check, were utilised in volumetric modulated arc therapy plans for 26 patients (14 with Arc Check and 12 with 4DOCT). Plans were administered using Varian Unique machine (with 4DOCT) and Varian TrueBeam (with Arc Check), each employing different calibration factors (CFs): 4 × 4, 6 × 6, 8 × 8, 10 × 10, 12 × 12 and 15 × 15 cm2 field sizes. Gamma analysis was conducted with 2%2mm, 2%3mm and 3%3mm gamma criteria. Results: GPR exhibited variations across different CFs. GPR demonstrated an increasing trend below 10 × 10 cm² CFs, while it displayed a decreasing trend above 10 × 10 cm². Both detectors exhibited similar GPR patterns. The correlation between 4DOCT and Arc Check was strong in tighter criteria (2%2mm) with an R² value of 0·9957, moderate criteria (2%3mm) with an R² value of 0·9868, but reduced in liberal criteria (3%3mm) with an R² value of 0·4226. Conclusion: This study demonstrates that calibration field sizes significantly influence GPR in PSQA. This study recommends the plan specific calibration field must obtain to calibrate the QA devices for modulated plans.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139438672","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}
Pub Date : 2024-01-09DOI: 10.1017/S1460396923000420
C. Ying, M. Arif Efendi, Susanna Guatelli, L. Tran, D. Bolst
Abstract Introduction: This work calculates the microdosimetric spectra and evaluates the relative biological effectiveness (RBE10) of oxygen and carbon ions using Monte Carlo simulation. This study presents a fast, reliable radiation field characterisation and accurate biological dose prediction tool in charged particle therapy for heavy-ion beams using the Bridge silicon-on-insulator (SOI) microdosimeter via Tool for Particle Simulation (TOPAS)-based simulations toolkit. Method: The study used the TOPAS simulation to model the Bridge SOI microdosimeter and study its response to carbon beams with an energy of 290 MeV/u and oxygen beams with an energy of 345 MeV/u. Dose-mean lineal energy values $(overline {{y_D});} $ and RBE10 values were evaluated using microdosimetric lineal energy spectra with the MKM model. Results and Conclusions: The results demonstrate that oxygen ion beams have an advantage for cancer treatment as they provide higher RBE10 values and occur at the same positions as the maximum physical dose (Bragg peak), compared to carbon ion beams. The study provides new understanding of RBE for carbon and oxygen ions, as well as the relationship between physical doses and RBE.
{"title":"Secondary fragmentation and relative biological effectiveness (RBE) study using Bridge SOI microdosimeter: Monte Carlo simulation","authors":"C. Ying, M. Arif Efendi, Susanna Guatelli, L. Tran, D. Bolst","doi":"10.1017/S1460396923000420","DOIUrl":"https://doi.org/10.1017/S1460396923000420","url":null,"abstract":"Abstract Introduction: This work calculates the microdosimetric spectra and evaluates the relative biological effectiveness (RBE10) of oxygen and carbon ions using Monte Carlo simulation. This study presents a fast, reliable radiation field characterisation and accurate biological dose prediction tool in charged particle therapy for heavy-ion beams using the Bridge silicon-on-insulator (SOI) microdosimeter via Tool for Particle Simulation (TOPAS)-based simulations toolkit. Method: The study used the TOPAS simulation to model the Bridge SOI microdosimeter and study its response to carbon beams with an energy of 290 MeV/u and oxygen beams with an energy of 345 MeV/u. Dose-mean lineal energy values \u0000$(overline {{y_D});} $\u0000 and RBE10 values were evaluated using microdosimetric lineal energy spectra with the MKM model. Results and Conclusions: The results demonstrate that oxygen ion beams have an advantage for cancer treatment as they provide higher RBE10 values and occur at the same positions as the maximum physical dose (Bragg peak), compared to carbon ion beams. The study provides new understanding of RBE for carbon and oxygen ions, as well as the relationship between physical doses and RBE.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139444107","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}
Pub Date : 2024-01-01Epub Date: 2024-04-15DOI: 10.1017/s1460396924000037
Ryan T Hughes, Beverly J Levine, Bart A Frizzell, Kathryn M Greven, Mercedes Porosnicu, Thomas W Lycan, Luke R Burnett, Karen M Winkfield
Introduction: Radiation dermatitis (RD) is a frequent toxicity during radiotherapy (RT) for head and neck cancer (HNC). We report the first use of KeraStat® Cream (KC), a topical, keratin-based wound dressing, in patients with HNC receiving RT.
Methods: This pilot study randomized HNC patients treated with definitive or postoperative RT (≥60 Gy) to KC or standard of care (SOC), applied at least twice daily during and for 1-month after RT. Outcomes of interest included adherence to the assigned regimen (at least 10 applications per week of treatment), clinician- and patient-reported RD, and skin-related quality of life.
Results: 24 patients were randomized and completed the study. Most patients had stage III-IV disease and oropharynx cancer. Median RT dose was 68 Gy; the bilateral neck was treated in 19 patients, and 18 patients received concurrent chemotherapy. Complete adherence was observed in 7/12 (SOC) vs. 10/12 (KC, p = 0.65). Adherence by patient-week was 61/68 versus 64/67, respectively (p = 0.20). No differences in RD were observed between groups.
Conclusion: A randomized trial of KC versus SOC in HNC patients treated with RT is feasible with good adherence to study agent. An adequately powered randomized study is warranted to test the efficacy of KC in reducing RD.
{"title":"Keratin-based topical cream for radiation dermatitis during head and neck radiotherapy: a randomised, open-label pilot study.","authors":"Ryan T Hughes, Beverly J Levine, Bart A Frizzell, Kathryn M Greven, Mercedes Porosnicu, Thomas W Lycan, Luke R Burnett, Karen M Winkfield","doi":"10.1017/s1460396924000037","DOIUrl":"10.1017/s1460396924000037","url":null,"abstract":"<p><strong>Introduction: </strong>Radiation dermatitis (RD) is a frequent toxicity during radiotherapy (RT) for head and neck cancer (HNC). We report the first use of KeraStat<sup>®</sup> Cream (KC), a topical, keratin-based wound dressing, in patients with HNC receiving RT.</p><p><strong>Methods: </strong>This pilot study randomized HNC patients treated with definitive or postoperative RT (≥60 Gy) to KC or standard of care (SOC), applied at least twice daily during and for 1-month after RT. Outcomes of interest included adherence to the assigned regimen (at least 10 applications per week of treatment), clinician- and patient-reported RD, and skin-related quality of life.</p><p><strong>Results: </strong>24 patients were randomized and completed the study. Most patients had stage III-IV disease and oropharynx cancer. Median RT dose was 68 Gy; the bilateral neck was treated in 19 patients, and 18 patients received concurrent chemotherapy. Complete adherence was observed in 7/12 (SOC) vs. 10/12 (KC, <i>p</i> = 0.65). Adherence by patient-week was 61/68 versus 64/67, respectively (<i>p</i> = 0.20). No differences in RD were observed between groups.</p><p><strong>Conclusion: </strong>A randomized trial of KC versus SOC in HNC patients treated with RT is feasible with good adherence to study agent. An adequately powered randomized study is warranted to test the efficacy of KC in reducing RD.</p>","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11449460/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142373162","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}
Pub Date : 2023-11-30DOI: 10.1017/S1460396923000419
B. K. Barik, J. Jena, Dillip Kumar Sahoo, Anupama Muraleedharan, Santosh Kumar Parida, Bikash Ranjan Mohapatra, S. Barik, D. Das, S. D. Das Majumdar, D. Parida
{"title":"Single catheter 3d volume based hybrid inverse planning optimization in IVBT can improve organ sparing – CORRIGENDUM","authors":"B. K. Barik, J. Jena, Dillip Kumar Sahoo, Anupama Muraleedharan, Santosh Kumar Parida, Bikash Ranjan Mohapatra, S. Barik, D. Das, S. D. Das Majumdar, D. Parida","doi":"10.1017/S1460396923000419","DOIUrl":"https://doi.org/10.1017/S1460396923000419","url":null,"abstract":"","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139206317","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}
Pub Date : 2023-08-25DOI: 10.1017/S1460396923000304
Zhaohui Xie
Abstract A case study comparing three-dimensional conformal radiation therapy with field-in-field (FiF) technique and volumetric-modulated arc therapy (VMAT) for head/neck (H/N) irradiation, evaluating the differences in the treatment techniques and low doses to critical structures. Compared to VMAT plan, 3D FIF plan offers similar planning target volume coverage and acceptable organs at risk dose. Therefore, 3D FIF is still a feasible alternative for some centres unqualified for IMRT/VMAT worldwide.
{"title":"Dosimetric case study of 3-D FiF vs. VMAT techniques in the treatment of H/N tumour","authors":"Zhaohui Xie","doi":"10.1017/S1460396923000304","DOIUrl":"https://doi.org/10.1017/S1460396923000304","url":null,"abstract":"Abstract A case study comparing three-dimensional conformal radiation therapy with field-in-field (FiF) technique and volumetric-modulated arc therapy (VMAT) for head/neck (H/N) irradiation, evaluating the differences in the treatment techniques and low doses to critical structures. Compared to VMAT plan, 3D FIF plan offers similar planning target volume coverage and acceptable organs at risk dose. Therefore, 3D FIF is still a feasible alternative for some centres unqualified for IMRT/VMAT worldwide.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48647242","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}
Pub Date : 2023-07-28DOI: 10.1017/S1460396923000298
Bhuvana J, Akash Pandya, M. Mehta, S. U
Abstract Background: Secondary oesophageal carcinoma from a breast primary is an infrequent phenomenon. Given the rarity of this presentation, there is a general lack of consensus on management guidelines. Materials and methods: Herein, we report a case of a 65-year-old female presented with dysphagia, 14 years post-surgery for breast cancer. She was diagnosed with oesophageal metastases and was treated with combination of systemic chemotherapy, hormonal therapy and local radiotherapy. Our patient tolerated the treatment well and achieved a significant symptomatic improvement post-radiotherapy. We also performed a review of literature on oesophageal metastases from breast primary, aiming to improve the diagnostic accuracy and treatment efficacy in this rare presentation. Conclusions: We conclude that patients who present with persistent dysphagia post-breast cancer treatment should undergo an endoscopic ultrasound (EUS)-guided fine-needle biopsy (FNB) to rule out oesophageal metastasis. We suggest systemic chemotherapy with hormonal therapy and radiotherapy for local control as a management of choice in this condition. Even though prognosis is difficult to predict in these patients, this combined modality of treatment seems to achieve better overall survival.
{"title":"Metastatic breast cancer to oesophagus: a case report and review of the literature","authors":"Bhuvana J, Akash Pandya, M. Mehta, S. U","doi":"10.1017/S1460396923000298","DOIUrl":"https://doi.org/10.1017/S1460396923000298","url":null,"abstract":"Abstract Background: Secondary oesophageal carcinoma from a breast primary is an infrequent phenomenon. Given the rarity of this presentation, there is a general lack of consensus on management guidelines. Materials and methods: Herein, we report a case of a 65-year-old female presented with dysphagia, 14 years post-surgery for breast cancer. She was diagnosed with oesophageal metastases and was treated with combination of systemic chemotherapy, hormonal therapy and local radiotherapy. Our patient tolerated the treatment well and achieved a significant symptomatic improvement post-radiotherapy. We also performed a review of literature on oesophageal metastases from breast primary, aiming to improve the diagnostic accuracy and treatment efficacy in this rare presentation. Conclusions: We conclude that patients who present with persistent dysphagia post-breast cancer treatment should undergo an endoscopic ultrasound (EUS)-guided fine-needle biopsy (FNB) to rule out oesophageal metastasis. We suggest systemic chemotherapy with hormonal therapy and radiotherapy for local control as a management of choice in this condition. Even though prognosis is difficult to predict in these patients, this combined modality of treatment seems to achieve better overall survival.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43949769","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}
Pub Date : 2023-07-24DOI: 10.1017/S1460396923000274
J. A. Rojas-López, M. Chesta, C. Venencia
Abstract Purpose: We compare the accuracy of the off-axis Winston–Lutz (WL) test in two versions of ExacTracTM: version 6.0 (ETv6) and Dynamic (ETD) in the same linac (TrueBeam STx®). Materials and methods: An upgraded of the ExacTracTM system was done in our institution. It was designed as an off-axis WL test before the update for comparison purposes. A head 3D-printed phantom based on a patient’s computed tomography images was used. Nine metallic fiducials were inserted and distributed on the phantom. Each target (fiducial) was designed an off-axis WL test with eight different gantry/collimator/table combinations. The phantom was placed using two different ETv6 and ETD in the same linac, and cone-beam computed tomography and electronic portal imaging device (EPID) images were acquired. The 2D deviation between the centre of the fiducial and the radiation field was found and compared with the original digital reconstructed radiography (DRR) by the profiles. Results: The phantom allows the definition of a procedure to determine off-axis deviations in radiosurgery treatments. The displacements calculated from the WL test showed acceptable values for both versions taking into account 3D displacement tolerances of 1 mm. These values were reached with rigorous quality assurance (QA) linac tests performed routinely that include mechanical, MV/kV and image-guided radiotherapy (IGRT) tests. However, ETD indicated more accurate values for all the targets no matter the distance to the isocentre (3D displacements < 0·5 mm). Conclusion: In terms of the IGRT correction without set-up displacements, ETD is up to twice as accurate as the ETv6, showing 3D displacements up to 0·5 mm in all targets.
{"title":"Experimental determination of set-up displacements in anthropomorphic phantom in single-isocentre radiosurgery for multiple brain metastases by off-axis Winston–Lutz test: ExacTracTM v.6 versus DynamicTM","authors":"J. A. Rojas-López, M. Chesta, C. Venencia","doi":"10.1017/S1460396923000274","DOIUrl":"https://doi.org/10.1017/S1460396923000274","url":null,"abstract":"Abstract Purpose: We compare the accuracy of the off-axis Winston–Lutz (WL) test in two versions of ExacTracTM: version 6.0 (ETv6) and Dynamic (ETD) in the same linac (TrueBeam STx®). Materials and methods: An upgraded of the ExacTracTM system was done in our institution. It was designed as an off-axis WL test before the update for comparison purposes. A head 3D-printed phantom based on a patient’s computed tomography images was used. Nine metallic fiducials were inserted and distributed on the phantom. Each target (fiducial) was designed an off-axis WL test with eight different gantry/collimator/table combinations. The phantom was placed using two different ETv6 and ETD in the same linac, and cone-beam computed tomography and electronic portal imaging device (EPID) images were acquired. The 2D deviation between the centre of the fiducial and the radiation field was found and compared with the original digital reconstructed radiography (DRR) by the profiles. Results: The phantom allows the definition of a procedure to determine off-axis deviations in radiosurgery treatments. The displacements calculated from the WL test showed acceptable values for both versions taking into account 3D displacement tolerances of 1 mm. These values were reached with rigorous quality assurance (QA) linac tests performed routinely that include mechanical, MV/kV and image-guided radiotherapy (IGRT) tests. However, ETD indicated more accurate values for all the targets no matter the distance to the isocentre (3D displacements < 0·5 mm). Conclusion: In terms of the IGRT correction without set-up displacements, ETD is up to twice as accurate as the ETv6, showing 3D displacements up to 0·5 mm in all targets.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43439047","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}
Pub Date : 2023-07-20DOI: 10.1017/S1460396923000286
H. Fuse, Fumihiro Tomita, Kenji Yasue, Hideaki Ikoma, Shin Miyakawa, Norikazu Kori, T. Fujisaki, Y. Ishimori, M. Monma, T. Okumura, Y. Tamaki
Abstract Background: Brachytherapy is an effective local treatment for early-stage head and neck cancers. Mold irradiation is a method in which the source is placed in the oral cavity in sites where the soft tissue is thin and an irradiation source cannot be implanted. However, dose calculations based on TG-43 may be subject to uncertainty due to the heterogeneity of tissues and materials used for the irradiation of head and neck cancers. Materials and Methods: In this study, we investigated the basic physical properties of different materials and densities in the molds, retrospectively analysed patient plans and verified the doses of intraoral mold irradiation using a dose verification system with MC simulations specifically designed for brachytherapy, which was constructed independently. Results and Discussion: Dose–volume histograms were obtained with a treatment planning system (TG-43) and MC simulation and revealed a non-negligible difference in coverage of high-risk clinical target volume (HR-CTV) and organ at risk (OAR) between calculations using computed tomography values and those with density changes. The underdose was 10·6%, 3·7% and 5·6% for HR-CTV, gross tumour volume and OAR, respectively, relative to the treatment plan. The calculations based on the differences in the elemental composition and density changes in TG-43, a water-based calculation algorithm, resulted in clinically significant dose differences. The validation method was used only for the cases of complex small source therapy. Conclusion: The findings of this study can be applied to more complex cases with steeper density gradients, such as mold irradiation.
{"title":"Verification of dose distribution by different material properties in intraoral mold irradiation","authors":"H. Fuse, Fumihiro Tomita, Kenji Yasue, Hideaki Ikoma, Shin Miyakawa, Norikazu Kori, T. Fujisaki, Y. Ishimori, M. Monma, T. Okumura, Y. Tamaki","doi":"10.1017/S1460396923000286","DOIUrl":"https://doi.org/10.1017/S1460396923000286","url":null,"abstract":"Abstract Background: Brachytherapy is an effective local treatment for early-stage head and neck cancers. Mold irradiation is a method in which the source is placed in the oral cavity in sites where the soft tissue is thin and an irradiation source cannot be implanted. However, dose calculations based on TG-43 may be subject to uncertainty due to the heterogeneity of tissues and materials used for the irradiation of head and neck cancers. Materials and Methods: In this study, we investigated the basic physical properties of different materials and densities in the molds, retrospectively analysed patient plans and verified the doses of intraoral mold irradiation using a dose verification system with MC simulations specifically designed for brachytherapy, which was constructed independently. Results and Discussion: Dose–volume histograms were obtained with a treatment planning system (TG-43) and MC simulation and revealed a non-negligible difference in coverage of high-risk clinical target volume (HR-CTV) and organ at risk (OAR) between calculations using computed tomography values and those with density changes. The underdose was 10·6%, 3·7% and 5·6% for HR-CTV, gross tumour volume and OAR, respectively, relative to the treatment plan. The calculations based on the differences in the elemental composition and density changes in TG-43, a water-based calculation algorithm, resulted in clinically significant dose differences. The validation method was used only for the cases of complex small source therapy. Conclusion: The findings of this study can be applied to more complex cases with steeper density gradients, such as mold irradiation.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45816907","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}
Pub Date : 2023-07-03DOI: 10.1017/S1460396923000225
A. Clark, G. Wright, J. Mason, O. Hulson, A. Henry, S. Rodda, P. Bownes
Abstract Introduction: This study investigates the dose escalation to dominant intra-prostatic lesions (DILs) that is achievable using single-source-strength (SSS) and dual-source-strength (DSS) low-dose-rate (LDR) prostate brachytherapy and a sector-based plan approach. Methods: Twenty patients were retrospectively analysed. Image registration and planning were undertaken using VariSeed v9·0. SSS and DSS boost plans were produced and compared to clinical plans. Dosimetric robustness to seed displacement for SSS and DSS plans was compared to clinical plans using Monte Carlo simulations. Results: Fourteen out of 20 patients had DIL identifiable on magnetic resonance imaging. Median increase in sector D90 of 27% (p < 0·0001) and sector V150 of 31% (p < 0·0001) was achieved with SSS planning without exceeding local rectum and urethra dose constraints. DSS plans achieved dose distributions not statistically significantly different from the SSS plans with a median of eight fewer seeds and two fewer needles. SSS and DSS plan sensitivity to random seed displacement was similar to the clinical plans. Conclusions: Treatment planning using VariSeed to produce SSS and DSS focal boost plans is feasible for LDR prostate brachytherapy to achieve a median escalation in sector D90 of 27% without exceeding local urethral and rectal constraints. SSS and DSS plan dosimetric robustness was similar to clinical plan dosimetric robustness.
{"title":"Single- and dual-source-strength focal boost planning in low-dose-rate prostate brachytherapy: feasibility study","authors":"A. Clark, G. Wright, J. Mason, O. Hulson, A. Henry, S. Rodda, P. Bownes","doi":"10.1017/S1460396923000225","DOIUrl":"https://doi.org/10.1017/S1460396923000225","url":null,"abstract":"Abstract Introduction: This study investigates the dose escalation to dominant intra-prostatic lesions (DILs) that is achievable using single-source-strength (SSS) and dual-source-strength (DSS) low-dose-rate (LDR) prostate brachytherapy and a sector-based plan approach. Methods: Twenty patients were retrospectively analysed. Image registration and planning were undertaken using VariSeed v9·0. SSS and DSS boost plans were produced and compared to clinical plans. Dosimetric robustness to seed displacement for SSS and DSS plans was compared to clinical plans using Monte Carlo simulations. Results: Fourteen out of 20 patients had DIL identifiable on magnetic resonance imaging. Median increase in sector D90 of 27% (p < 0·0001) and sector V150 of 31% (p < 0·0001) was achieved with SSS planning without exceeding local rectum and urethra dose constraints. DSS plans achieved dose distributions not statistically significantly different from the SSS plans with a median of eight fewer seeds and two fewer needles. SSS and DSS plan sensitivity to random seed displacement was similar to the clinical plans. Conclusions: Treatment planning using VariSeed to produce SSS and DSS focal boost plans is feasible for LDR prostate brachytherapy to achieve a median escalation in sector D90 of 27% without exceeding local urethral and rectal constraints. SSS and DSS plan dosimetric robustness was similar to clinical plan dosimetric robustness.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47393562","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}
Pub Date : 2023-06-29DOI: 10.1017/S1460396923000250
Siwika Thongthanom, W. Nobnop
Abstract Purpose: This study aimed to determine the suitable breast treatment technique for a small facility’s hospital with limited staff and equipment resources. The benefits and drawbacks of each technique should be considered to guide radiation oncologists choose the appropriate treatment option for postmastectomy radiation therapy (PMRT) patients. Methods and Materials: This study included the computed tomography images of 15 patients who received left-sided PMRT. The patient’s characteristics were classified into two groups: 1. irradiation of only the chest wall (CW) and 2. CW lymph nodes plus supraclavicular lymph nodes (SPCs). All 15 PMRT patients were generated in 4 treatment techniques including 3DCRT, field-in-field (FiF), intensity-modulated radiotherapy (IMRT) and hybrid (3DCRT + IMRT). Each treatment technique’s dosimetric parameters and treatment time were compared. Result: All four treatment plans met the acceptable criteria. The IMRT plans achieved the highest plan quality scores for two groups of PMRT patients but require the longest treatment time, whereas the 3DCRT and FiF plans demonstrated superiority for organ at risk (OAR) sparing and required the shortest treatment time when compared with the IMRT and hybrid plans. Conclusion: The IMRT plan had the highest plan quality but required the most time to treat. Treatment times are critical in facilities with limited resources. As a result, the FiF plan was found to be a suitable technique for both CW-only and CW plus SPC irradiation due to its short treatment time and high plan quality scores for OAR dose sparing.
{"title":"Dosimetric comparison of three-dimensional (3D), intensity-modulated radiotherapy (IMRT) and hybrid IMRT for left-sided postmastectomy radiation therapy (PMRT)","authors":"Siwika Thongthanom, W. Nobnop","doi":"10.1017/S1460396923000250","DOIUrl":"https://doi.org/10.1017/S1460396923000250","url":null,"abstract":"Abstract Purpose: This study aimed to determine the suitable breast treatment technique for a small facility’s hospital with limited staff and equipment resources. The benefits and drawbacks of each technique should be considered to guide radiation oncologists choose the appropriate treatment option for postmastectomy radiation therapy (PMRT) patients. Methods and Materials: This study included the computed tomography images of 15 patients who received left-sided PMRT. The patient’s characteristics were classified into two groups: 1. irradiation of only the chest wall (CW) and 2. CW lymph nodes plus supraclavicular lymph nodes (SPCs). All 15 PMRT patients were generated in 4 treatment techniques including 3DCRT, field-in-field (FiF), intensity-modulated radiotherapy (IMRT) and hybrid (3DCRT + IMRT). Each treatment technique’s dosimetric parameters and treatment time were compared. Result: All four treatment plans met the acceptable criteria. The IMRT plans achieved the highest plan quality scores for two groups of PMRT patients but require the longest treatment time, whereas the 3DCRT and FiF plans demonstrated superiority for organ at risk (OAR) sparing and required the shortest treatment time when compared with the IMRT and hybrid plans. Conclusion: The IMRT plan had the highest plan quality but required the most time to treat. Treatment times are critical in facilities with limited resources. As a result, the FiF plan was found to be a suitable technique for both CW-only and CW plus SPC irradiation due to its short treatment time and high plan quality scores for OAR dose sparing.","PeriodicalId":44597,"journal":{"name":"Journal of Radiotherapy in Practice","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45819063","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}
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