Tolerance limits and methodologies for IMRT measurement-based verification QA: Recommendations of AAPM Task Group No. 218
Tolerance limits and methodologies for IMRT measurement-based verification QA: Recommendations of AAPM Task Group No. 218
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DOI：
10.1002/mp.12810
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发表时间：
2018-04-01
期刊：
影响因子：
3.8
通讯作者：
Low, Daniel A.
中科院分区：
文献类型：
--
作者：
Miften, Moyed;Olch, Arthur;Low, Daniel A.
患者特定调强放射治疗质量保证（QA）测量是识别计算剂量与实际剂量之间差异的重要组成部分。不同的公差限值既没有明确定义，也没有在各中心一致应用。AAPM TG-218报告提供了一个全面的审查，旨在提高这些过程的理解和一致性，以及在患者特定的IMRT QA的方法和公差限制的建议。MethodsThe性能的剂量差异/距离协议（DTA）和剂量分布比较指标进行了调查。衡量方法进行审查，并随后讨论的利弊。绝对剂量验证的方法进行了讨论，提出了新的调强放射治疗QA验证工具。文献的预期或可实现的协议之间的测量和计算不同类型的规划和交付系统进行审查和分析。供应商实施的验证算法采用基准cases.ResultsOperational的缺点，可以降低工具的准确性和随后的有效性IMRT QA的测试。实际考虑，包括空间分辨率，归一化，剂量阈值，和数据解释进行了讨论。IMRT QA的已发表数据和小组成员的临床经验用于制定IMRT QA的公差和行动限的指南和建议。步骤检查失败的IMRT QA plans outlined.ConclusionRecommendations上的交付方法，数据解释，剂量归一化，使用的分析例程和选择的公差限制IMRT QA的重点是通过使用强大的分析方法和深入了解IMRT验证指标检测计算和测量的剂量之间的差异。这些建议旨在改善调强放射治疗质量保证过程，并在机构之间建立一致的、可比较的调强放射治疗质量保证标准。
PurposePatient-specific IMRT QA measurements are important components of processes designed to identify discrepancies between calculated and delivered radiation doses. Discrepancy tolerance limits are neither well defined nor consistently applied across centers. The AAPM TG-218 report provides a comprehensive review aimed at improving the understanding and consistency of these processes as well as recommendations for methodologies and tolerance limits in patient-specific IMRT QA.MethodsThe performance of the dose difference/distance-to-agreement (DTA) and dose distribution comparison metrics are investigated. Measurement methods are reviewed and followed by a discussion of the pros and cons of each. Methodologies for absolute dose verification are discussed and new IMRT QA verification tools are presented. Literature on the expected or achievable agreement between measurements and calculations for different types of planning and delivery systems are reviewed and analyzed. Tests of vendor implementations of the verification algorithm employing benchmark cases are presented.ResultsOperational shortcomings that can reduce the tool accuracy and subsequent effectiveness for IMRT QA are described. Practical considerations including spatial resolution, normalization, dose threshold, and data interpretation are discussed. Published data on IMRT QA and the clinical experience of the group members are used to develop guidelines and recommendations on tolerance and action limits for IMRT QA. Steps to check failed IMRT QA plans are outlined.ConclusionRecommendations on delivery methods, data interpretation, dose normalization, the use of analysis routines and choice of tolerance limits for IMRT QA are made with focus on detecting differences between calculated and measured doses via the use of robust analysis methods and an in-depth understanding of IMRT verification metrics. The recommendations are intended to improve the IMRT QA process and establish consistent, and comparable IMRT QA criteria among institutions.