Shielding Analysis of a Preclinical Bremsstrahlung X-ray FLASH Radiotherapy System within a Clinical Radiation Therapy Vault

Author:

Rosenstrom Andrew,Santana-Leitner Mario1,Rokni Sayed1,Shumail Muhammad2,Tantawi Sami2,Kwofie John3,Dewji Shaheen4,Loo Billy W.5

Affiliation:

1. Radiation Protection Department, SLAC, MS 48, 2575 Sand Hill Road, Menlo Park, CA 94025

2. Technology Innovation Department, SLAC, MS 48, 2575 Sand Hill Road, Menlo Park, CA 94025

3. Occupational Health Center, Stanford University ESF-480 Oak Rd, Stanford, CA 94305

4. Nuclear & Radiological Engineering & Medical Physics Programs Georgia Institute of Technology, North Ave NW, Atlanta, GA 30332

5. Department of Radiation Oncology and Stanford Cancer Institute, Stanford University School of Medicine, 875 Blake Wilbur Drive, Stanford CA 94305.

Abstract

Abstract A preclinical radiotherapy system producing FLASH dose rates with 12 MV bremsstrahlung x rays is being developed at Stanford University and SLAC National Accelerator Laboratory. Because of the high expected workload of 6,800 Gy w−1 at the isocenter, an efficient shielding methodology is needed to protect operators and the public while the preclinical system is operated in a radiation therapy vault designed for 6 MV x rays. In this study, an analysis is performed to assess the shielding of the local treatment head and radiation vault using the Monte Carlo code FLUKA and the empirical methodology given in the National Council on Radiation Protection and Measurements Report 151. Two different treatment head shielding designs were created to compare single-layer and multilayer shielding methodologies using high-Z and low-Z materials. The multilayered shielding methodology produced designs with a 17% reduction in neutron fluence leaking from the treatment head compared to the single layered design of the same size, resulting in a decreased effective dose to operators and the public. The conservative assumptions used in the empirical methods can lead to over-shielding when treatment heads use polyethylene or multilayered shielding. High-Z/Low-Z multilayered shielding optimized via Monte Carlo is shown to be effective in the case of treatment head shielding and provide more effective shielding design for external beam radiotherapy systems that use 12 MV bremsstrahlung photons. Modifications to empirical methods used in the assessment of MV radiotherapy systems may be warranted to capture the effects of polyethylene in treatment head shielding.

Publisher

Ovid Technologies (Wolters Kluwer Health)

Subject

Health, Toxicology and Mutagenesis,Radiology, Nuclear Medicine and imaging,Epidemiology

Reference12 articles.

1. The FLUKA code: developments and challenges for high energy and medical applications;Nuclear Data Sheets,2014

2. A method to optimize the shield compact and lightweight combining the structure with components together by genetic algorithm and MCNP code;Appl Radiat Isotope,2018

3. Physics and biology of ultrahigh dose-rate (FLASH) radiotherapy: a topical review;Phys Med Biol,2020

4. Ultrahigh dose-rate FLASH irradiation increases the differential response between normal and tumor tissue in mice;Sci Transl Med,2014

5. Understanding high-dose, ultra-high dose rate, and spatially fractionated radiation therapy;Int J Radiat Oncol Biol Phys,2020

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3