Mahmoud H Abdelgawad, Ahmed A Eldib, Tamer M Elsayed, Cm Charlie Ma
{"title":"研究用于脉冲低剂量率放射治疗的直线加速器低剂量率模式。","authors":"Mahmoud H Abdelgawad, Ahmed A Eldib, Tamer M Elsayed, Cm Charlie Ma","doi":"10.1088/2057-1976/ad73dd","DOIUrl":null,"url":null,"abstract":"<p><p><i>Purpose</i>. Pulsed volumetric modulated arc therapy (VMAT) was proposed as an advanced treatment that combines the biological benefits of pulsed low dose rate (PLDR) and the dosimetric benefits of the intensity-modulated beams. In our conventional pulsed VMAT technique, a daily fractional dose of 200 cGy is delivered in 10 arcs with 3 min intervals between the arcs. In this study, we are testing the feasibility of pulsed VMAT that omits the need to split into ten arcs and excludes any beam-off gaps.<i>Methods</i>. The study was conducted using computed tomographic images of 24 patients previously treated at our institution with the conventional PLDR technique. Our newly installed Elekta machine has a low dose rate option on the order of 25 MU min<sup>-1</sup>. PLDR requires an effective dose rate of 6.7 cGy min<sup>-1</sup>with attention being paid to the maximum dose received within any point within the target not to exceed 13 cGy min<sup>-1</sup>. The quality of treatment plans was judged based on dose-volume histograms, isodose distribution, dose conformality to the target, and target dose homogeneity. The dose delivery accuracy was assessed by measurements using the<i>MatriXX</i><sup><i>Evolution</i></sup>2D array system.<i>Results</i>. All cases were normalized to cover 95% of the target volume with 100% of the prescription dose. The average conformity index was 1.03 ± 0.08 while the average homogeneity index was 1.05 ± 0.02. The maximum reported dose rate at any point within the target was 10.44 cGy min<sup>-1</sup>. The mean dose rate for all pulsed VMAT plans was 6.88 ± 0.1 cGy min<sup>-1</sup>. All cases passed our gamma analysis with an average passing rate of 99.00% ± 0.48%.<i>Conclusion</i>. The study showed the applicability of planning pulsed VMAT using Eclipse and its successful delivery on our Elekta linac. Pulsed VMAT using the machine's low dose rate mode is more efficient than our previous pulsed VMAT delivery.</p>","PeriodicalId":8896,"journal":{"name":"Biomedical Physics & Engineering Express","volume":" ","pages":""},"PeriodicalIF":1.3000,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Investigation of the linear accelerator low dose rate mode for pulsed low-dose-rate radiotherapy delivery.\",\"authors\":\"Mahmoud H Abdelgawad, Ahmed A Eldib, Tamer M Elsayed, Cm Charlie Ma\",\"doi\":\"10.1088/2057-1976/ad73dd\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p><i>Purpose</i>. Pulsed volumetric modulated arc therapy (VMAT) was proposed as an advanced treatment that combines the biological benefits of pulsed low dose rate (PLDR) and the dosimetric benefits of the intensity-modulated beams. In our conventional pulsed VMAT technique, a daily fractional dose of 200 cGy is delivered in 10 arcs with 3 min intervals between the arcs. In this study, we are testing the feasibility of pulsed VMAT that omits the need to split into ten arcs and excludes any beam-off gaps.<i>Methods</i>. The study was conducted using computed tomographic images of 24 patients previously treated at our institution with the conventional PLDR technique. Our newly installed Elekta machine has a low dose rate option on the order of 25 MU min<sup>-1</sup>. PLDR requires an effective dose rate of 6.7 cGy min<sup>-1</sup>with attention being paid to the maximum dose received within any point within the target not to exceed 13 cGy min<sup>-1</sup>. The quality of treatment plans was judged based on dose-volume histograms, isodose distribution, dose conformality to the target, and target dose homogeneity. The dose delivery accuracy was assessed by measurements using the<i>MatriXX</i><sup><i>Evolution</i></sup>2D array system.<i>Results</i>. All cases were normalized to cover 95% of the target volume with 100% of the prescription dose. The average conformity index was 1.03 ± 0.08 while the average homogeneity index was 1.05 ± 0.02. The maximum reported dose rate at any point within the target was 10.44 cGy min<sup>-1</sup>. The mean dose rate for all pulsed VMAT plans was 6.88 ± 0.1 cGy min<sup>-1</sup>. All cases passed our gamma analysis with an average passing rate of 99.00% ± 0.48%.<i>Conclusion</i>. The study showed the applicability of planning pulsed VMAT using Eclipse and its successful delivery on our Elekta linac. Pulsed VMAT using the machine's low dose rate mode is more efficient than our previous pulsed VMAT delivery.</p>\",\"PeriodicalId\":8896,\"journal\":{\"name\":\"Biomedical Physics & Engineering Express\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.3000,\"publicationDate\":\"2024-09-11\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Biomedical Physics & Engineering Express\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1088/2057-1976/ad73dd\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biomedical Physics & Engineering Express","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1088/2057-1976/ad73dd","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
Investigation of the linear accelerator low dose rate mode for pulsed low-dose-rate radiotherapy delivery.
Purpose. Pulsed volumetric modulated arc therapy (VMAT) was proposed as an advanced treatment that combines the biological benefits of pulsed low dose rate (PLDR) and the dosimetric benefits of the intensity-modulated beams. In our conventional pulsed VMAT technique, a daily fractional dose of 200 cGy is delivered in 10 arcs with 3 min intervals between the arcs. In this study, we are testing the feasibility of pulsed VMAT that omits the need to split into ten arcs and excludes any beam-off gaps.Methods. The study was conducted using computed tomographic images of 24 patients previously treated at our institution with the conventional PLDR technique. Our newly installed Elekta machine has a low dose rate option on the order of 25 MU min-1. PLDR requires an effective dose rate of 6.7 cGy min-1with attention being paid to the maximum dose received within any point within the target not to exceed 13 cGy min-1. The quality of treatment plans was judged based on dose-volume histograms, isodose distribution, dose conformality to the target, and target dose homogeneity. The dose delivery accuracy was assessed by measurements using theMatriXXEvolution2D array system.Results. All cases were normalized to cover 95% of the target volume with 100% of the prescription dose. The average conformity index was 1.03 ± 0.08 while the average homogeneity index was 1.05 ± 0.02. The maximum reported dose rate at any point within the target was 10.44 cGy min-1. The mean dose rate for all pulsed VMAT plans was 6.88 ± 0.1 cGy min-1. All cases passed our gamma analysis with an average passing rate of 99.00% ± 0.48%.Conclusion. The study showed the applicability of planning pulsed VMAT using Eclipse and its successful delivery on our Elekta linac. Pulsed VMAT using the machine's low dose rate mode is more efficient than our previous pulsed VMAT delivery.
期刊介绍:
BPEX is an inclusive, international, multidisciplinary journal devoted to publishing new research on any application of physics and/or engineering in medicine and/or biology. Characterized by a broad geographical coverage and a fast-track peer-review process, relevant topics include all aspects of biophysics, medical physics and biomedical engineering. Papers that are almost entirely clinical or biological in their focus are not suitable. The journal has an emphasis on publishing interdisciplinary work and bringing research fields together, encompassing experimental, theoretical and computational work.