AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137
AAPM recommendations on dose prescription and reporting methods for permanent interstitial brachytherapy for prostate cancer: Report of Task Group 137
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DOI：
10.1118/1.3246613
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发表时间：
2009-11-01
期刊：
影响因子：
3.8
通讯作者：
Yu, Yan
中科院分区：
文献类型：
--
作者：
Nath, Ravinder;Bice, William S.;Yu, Yan
在过去的十年中，前列腺的永久性放射源植入已经成为选定的前列腺癌患者的护理标准，并且植入技术已经以许多不同的形式发展。虽然大多数植入物使用I-125或Pd-103源，但最近也引入了Cs-131源的临床使用。这些源产生不同的剂量分布，并以不同的剂量率照射肿瘤。超声最初用于引导肿瘤中源的规划和植入。最近，CT和/或MR在许多诊所中常规用于剂量评估和规划。几位研究者报告称，由于超声、CT和MR成像方式的固有差异，这些成像方式描绘的肿瘤体积和靶体积可能存在很大差异。据报道，这些体积主要取决于植入后的成像时间。许多诊所，特别是那些使用术中植入的诊所，仅在植入当天进行成像。由于手术创伤引起的水肿的影响可能因患者而异，并且以不同的速率消退，因此用于剂量测定评价的成像时间可能对报告的剂量（已输送）产生深远影响，即，对于相同的植入物（输送相同的剂量），不同时间的CT可以产生不同的报告剂量。此外，已经使用了许多不同的装载模式和肿瘤体积周围的边缘，并且这些可能导致递送剂量的变化。在这份报告中，目前的文献对这些问题进行了审查，并估计这些问题对放射生物学反应的影响。综述了生物等效剂量的放射生物学模型。从急性单次剂量的BED模型开始，对分次剂量、连续低剂量率照射、均匀和非均匀剂量分布以及肿瘤治愈概率模型进行了综述。基于这些文献的发展，AAPM从物理学角度为常规患者治疗、临床试验和治疗计划软件开发人员推荐了剂量处方指南。作者继续遵循目前关于使用D-90和V-100作为主要量的建议，并对成像模式的使用和成像时间提供了更具体的指导。AAPM建议，应在特定放射性核素的最佳时间进行植入后评价。此外，它们还鼓励使用具有一套特定参数的放射生物学模型，以便于对不同机构报告的使用不同装载模式或放射性核素的治疗计划进行相对比较。(C)2009年美国医学物理学家协会。[DOI：10.1118/1.3246613]
During the past decade, permanent radioactive source implantation of the prostate has become the standard of care for selected prostate cancer patients, and the techniques for implantation have evolved in many different forms. Although most implants use I-125 or Pd-103 sources, clinical use of Cs-131 sources has also recently been introduced. These sources produce different dose distributions and irradiate the tumors at different dose rates. Ultrasound was used originally to guide the planning and implantation of sources in the tumor. More recently, CT and/or MR are used routinely in many clinics for dose evaluation and planning. Several investigators reported that the tumor volumes and target volumes delineated from ultrasound, CT, and MR can vary substantially because of the inherent differences in these imaging modalities. It has also been reported that these volumes depend critically on the time of imaging after the implant. Many clinics, in particular those using intraoperative implantation, perform imaging only on the day of the implant. Because the effects of edema caused by surgical trauma can vary from one patient to another and resolve at different rates, the timing of imaging for dosimetry evaluation can have a profound effect on the dose reported (to have been delivered), i.e., for the same implant (same dose delivered), CT at different timing can yield different doses reported. Also, many different loading patterns and margins around the tumor volumes have been used, and these may lead to variations in the dose delivered. In this report, the current literature on these issues is reviewed, and the impact of these issues on the radiobiological response is estimated. The radiobiological models for the biological equivalent dose (BED) are reviewed. Starting with the BED model for acute single doses, the models for fractionated doses, continuous low-dose-rate irradiation, and both homogeneous and inhomogeneous dose distributions, as well as tumor cure probability models, are reviewed. Based on these developments in literature, the AAPM recommends guidelines for dose prescription from a physics perspective for routine patient treatment, clinical trials, and for treatment planning software developers. The authors continue to follow the current recommendations on using D-90 and V-100 as the primary quantities, with more specific guidelines on the use of the imaging modalities and the timing of the imaging. The AAPM recommends that the postimplant evaluation should be performed at the optimum time for specific radionuclides. In addition, they encourage the use of a radiobiological model with a specific set of parameters to facilitate relative comparisons of treatment plans reported by different institutions using different loading patterns or radionuclides. (C) 2009 American Association of Physicists in Medicine. [DOI: 10.1118/1.3246613]