Reducing stray radiation dose to patients receiving passively scattered proton radiotherapy for prostate cancer
Reducing stray radiation dose to patients receiving passively scattered proton radiotherapy for prostate cancer
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DOI：
10.1088/0031-9155/53/8/009
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发表时间：
2008-04-21
影响因子：
3.5
通讯作者：
Newhauser, Wayne D.
中科院分区：
文献类型：
--
作者：
Taddei, Phillip J.;Fontenot, Jonas D.;Newhauser, Wayne D.
质子束放射治疗使健康组织暴露于从治疗单元发出的杂散辐射和在患者体内产生的二次辐射。这些暴露没有提供已知的益处，并且可能增加患者发展放射性第二癌症的风险。本研究的目的是探讨策略，以减少杂散辐射剂量的患者接受76戈伊质子束治疗前列腺癌。使用被动散射质子治疗单元和拟人体模的详细蒙特卡罗模拟，估计杂散辐射的全身有效剂量E。E的预测值为567 mSv，其中320 mSv归因于治疗单元的泄漏;其余部分来自患者体内的散射辐射。对治疗装置进行适度的修改，使E减少了212 mSv。令人惊讶的是，来自改进的被动散射装置的E仅略高于（109 mSv）来自没有泄漏的喷嘴的E。例如，在一个实施例中，这可以用点扫描技术来处理。这些结果增加了支持被动散射质子束治疗前列腺癌的适用性的证据，证实了杂散辐射的有效剂量并不过量，并且重要的是，表明它可以通过适度增强治疗单元而大大减少。
Proton beam radiotherapy exposes healthy tissue to stray radiation emanating from the treatment unit and secondary radiation produced within the patient. These exposures provide no known benefit and may increase a patient's risk of developing a radiogenic second cancer. The aim of this study was to explore strategies to reduce stray radiation dose to a patient receiving a 76 Gy proton beam treatment for cancer of the prostate. The whole-body effective dose from stray radiation, E, was estimated using detailed Monte Carlo simulations of a passively scattered proton treatment unit and an anthropomorphic phantom. The predicted value of E was 567 mSv, of which 320 mSv was attributed to leakage from the treatment unit; the remainder arose from scattered radiation that originated within the patient. Modest modifications of the treatment unit reduced E by 212 mSv. Surprisingly, E from a modified passive-scattering device was only slightly higher ( 109 mSv) than from a nozzle with no leakage, e. g., that which may be approached with a spot-scanning technique. These results add to the body of evidence supporting the suitability of passively scattered proton beams for the treatment of prostate cancer, confirm that the effective dose from stray radiation was not excessive, and, importantly, show that it can be substantially reduced by modest enhancements to the treatment unit.