Hamid Reza Baghani, Ali Shiri, Hamid Gholamhosseinian
{"title":"利用混合模拟方法比较术中电子束和传统电子束的DNA损伤RBE。","authors":"Hamid Reza Baghani, Ali Shiri, Hamid Gholamhosseinian","doi":"10.1080/09553002.2023.2242931","DOIUrl":null,"url":null,"abstract":"<p><strong>Purpose: </strong>Employing electron beam for radiotherapy purposes now has been established as one of the standard cancer treatment modalities. Both dedicated intraoperative and conventional electron beams can be employed in patient irradiation. Due to the differences between accelerating structure and electron beam delivery of dedicated intraoperative radiotherapy (IORT) machines and conventional ones, the initial energy spectra of the produced electron beam by these machines may be different. Accordingly, this study aims to evaluate whether these spectral differences can affect the relevant relative biological effectiveness (RBE) values of intraoperative and conventional electron beams.</p><p><strong>Materials and methods: </strong>A hybrid Monte Carlo simulation approach was considered. At first, the head LIAC12 machine (as an IORT accelerator) and Varian 2100C/D (as a conventional accelerator) were simulated by MCNPX code and electron energy spectra at different depths and off-axis distances were scored for two nominal electron energies of 6 and 12 MeV at the field sizes of 6 and 10 cm. Then, the calculated spectra were imported to MCDS code to estimate the induced DNA-damage RBE values. Finally, the obtained RBE values for intraoperative and conventional electron beams were compared together.</p><p><strong>Results: </strong>The results showed that the RBE values of the intraoperative electron beam are superior to those obtained for conventional electron beam at the same energy/field size combination. Variations of the depth can regularly affect the RBE value for both conventional and intraoperative electron beams, while no ordered variation trend was observed for RBE with changing the off-axis distance. Variations of electron energy and field size can also influence the RBE value for both types of studied electron beams.</p><p><strong>Conclusions: </strong>From the results, it can be concluded the structural differences between the dedicated IORT and conventional Linacs can lead to distinct initial electron energy spectra for intraoperative and conventional electron beams. These physical differences can finally lead to different RBE values for intraoperative and conventional electron beams at the same energy and field size.</p>","PeriodicalId":14261,"journal":{"name":"International Journal of Radiation Biology","volume":null,"pages":null},"PeriodicalIF":2.1000,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Comparing the DNA-damage RBE of intraoperative and conventional electron beams using a hybrid simulation approach.\",\"authors\":\"Hamid Reza Baghani, Ali Shiri, Hamid Gholamhosseinian\",\"doi\":\"10.1080/09553002.2023.2242931\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Purpose: </strong>Employing electron beam for radiotherapy purposes now has been established as one of the standard cancer treatment modalities. Both dedicated intraoperative and conventional electron beams can be employed in patient irradiation. Due to the differences between accelerating structure and electron beam delivery of dedicated intraoperative radiotherapy (IORT) machines and conventional ones, the initial energy spectra of the produced electron beam by these machines may be different. Accordingly, this study aims to evaluate whether these spectral differences can affect the relevant relative biological effectiveness (RBE) values of intraoperative and conventional electron beams.</p><p><strong>Materials and methods: </strong>A hybrid Monte Carlo simulation approach was considered. At first, the head LIAC12 machine (as an IORT accelerator) and Varian 2100C/D (as a conventional accelerator) were simulated by MCNPX code and electron energy spectra at different depths and off-axis distances were scored for two nominal electron energies of 6 and 12 MeV at the field sizes of 6 and 10 cm. Then, the calculated spectra were imported to MCDS code to estimate the induced DNA-damage RBE values. Finally, the obtained RBE values for intraoperative and conventional electron beams were compared together.</p><p><strong>Results: </strong>The results showed that the RBE values of the intraoperative electron beam are superior to those obtained for conventional electron beam at the same energy/field size combination. Variations of the depth can regularly affect the RBE value for both conventional and intraoperative electron beams, while no ordered variation trend was observed for RBE with changing the off-axis distance. Variations of electron energy and field size can also influence the RBE value for both types of studied electron beams.</p><p><strong>Conclusions: </strong>From the results, it can be concluded the structural differences between the dedicated IORT and conventional Linacs can lead to distinct initial electron energy spectra for intraoperative and conventional electron beams. 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引用次数: 0
摘要
目的:利用电子束进行放射治疗现已成为标准的癌症治疗方法之一。术中专用电子束和传统电子束都可用于照射患者。由于专用术中放疗机(IORT)和传统放疗机的加速结构和电子束传输方式不同,其产生的电子束的初始能谱也可能不同。因此,本研究旨在评估这些光谱差异是否会影响术中和传统电子束的相关相对生物效应(RBE)值:材料和方法:采用混合蒙特卡罗模拟方法。首先,用MCNPX代码模拟了头部LIAC12机器(作为IORT加速器)和瓦里安2100C/D(作为传统加速器),并对6和12MeV两种标称电子能量、6和10厘米场强下不同深度和离轴距离的电子能谱进行了评分。然后,将计算出的光谱导入 MCDS 代码,估算诱导 DNA 损伤的 RBE 值。最后,将获得的术中电子束和传统电子束的RBE值进行比较:结果表明,在相同能量/场强组合下,术中电子束的RBE值优于传统电子束。深度的变化会对传统电子束和术中电子束的RBE值产生规律性影响,而RBE值并没有随着离轴距离的变化而出现有序的变化趋势。电子能量和磁场大小的变化也会影响所研究的两种电子束的 RBE 值:从研究结果中可以得出结论,专用IORT和传统Linac的结构差异会导致术中电子束和传统电子束的初始电子能谱不同。这些物理差异最终会导致相同能量和磁场大小的术中电子束和传统电子束产生不同的RBE值。
Comparing the DNA-damage RBE of intraoperative and conventional electron beams using a hybrid simulation approach.
Purpose: Employing electron beam for radiotherapy purposes now has been established as one of the standard cancer treatment modalities. Both dedicated intraoperative and conventional electron beams can be employed in patient irradiation. Due to the differences between accelerating structure and electron beam delivery of dedicated intraoperative radiotherapy (IORT) machines and conventional ones, the initial energy spectra of the produced electron beam by these machines may be different. Accordingly, this study aims to evaluate whether these spectral differences can affect the relevant relative biological effectiveness (RBE) values of intraoperative and conventional electron beams.
Materials and methods: A hybrid Monte Carlo simulation approach was considered. At first, the head LIAC12 machine (as an IORT accelerator) and Varian 2100C/D (as a conventional accelerator) were simulated by MCNPX code and electron energy spectra at different depths and off-axis distances were scored for two nominal electron energies of 6 and 12 MeV at the field sizes of 6 and 10 cm. Then, the calculated spectra were imported to MCDS code to estimate the induced DNA-damage RBE values. Finally, the obtained RBE values for intraoperative and conventional electron beams were compared together.
Results: The results showed that the RBE values of the intraoperative electron beam are superior to those obtained for conventional electron beam at the same energy/field size combination. Variations of the depth can regularly affect the RBE value for both conventional and intraoperative electron beams, while no ordered variation trend was observed for RBE with changing the off-axis distance. Variations of electron energy and field size can also influence the RBE value for both types of studied electron beams.
Conclusions: From the results, it can be concluded the structural differences between the dedicated IORT and conventional Linacs can lead to distinct initial electron energy spectra for intraoperative and conventional electron beams. These physical differences can finally lead to different RBE values for intraoperative and conventional electron beams at the same energy and field size.
期刊介绍:
The International Journal of Radiation Biology publishes original papers, reviews, current topic articles, technical notes/reports, and meeting reports on the effects of ionizing, UV and visible radiation, accelerated particles, electromagnetic fields, ultrasound, heat and related modalities. The focus is on the biological effects of such radiations: from radiation chemistry to the spectrum of responses of living organisms and underlying mechanisms, including genetic abnormalities, repair phenomena, cell death, dose modifying agents and tissue responses. Application of basic studies to medical uses of radiation extends the coverage to practical problems such as physical and chemical adjuvants which improve the effectiveness of radiation in cancer therapy. Assessment of the hazards of low doses of radiation is also considered.