Department of Radiation Oncology, University of California, Los Angeles, CA 90095, USA.
Med Phys. 2012 May;39(5):2708-12. doi: 10.1118/1.4704497.
The dosimetric aspects of radiation therapy treatment plan quality are usually evaluated and reported with dose volume histogram (DVH) endpoints. For clinical practicality, a small number of representative quantities derived from the DVH are often used as dose endpoints to summarize the plan quality. National guidelines on reference values for such quantities for some standard treatment approaches are often used as acceptance criteria to trigger treatment plan review. On the other hand, treatment prescription and planning approaches specific to each institution warrants the need to report plan quality in terms of practice consistency and with respect to institution-specific experience. The purpose of this study is to investigate and develop a systematic approach to record and characterize the institution-specific plan experience and use such information to guide the design of plan quality criteria. In the clinical setting, this approach will assist in (1) improving overall plan quality and consistency and (2) detecting abnormal plan behavior for retrospective analysis.
The authors propose a self-evolving methodology and have developed an in-house prototype software suite that (1) extracts the dose endpoints from a treatment plan and evaluates them against both national standard and institution-specific criteria and (2) evolves the statistics for the dose endpoints and updates institution-specific criteria.
The validity of the proposed methodology was demonstrated with a database of prostate stereotactic body radiotherapy cases. As more data sets are accumulated, the evolving institution-specific criteria can serve as a reliable and stable consistency measure for plan quality and reveals the potential use of the "tighter" criteria than national standards or projected criteria, leading to practice that may push to shrink the gap between plans deemed acceptable and the underlying unknown optimality.
The authors have developed a rationale to improve plan quality and consistency, by evolving the plan quality criteria from institution-specific experience, complementary to national standards. The validity of the proposed method was demonstrated with a prototype system on prostate stereotactic body radiotherapy (SBRT) cases. The current study uses direct and indirect DVH endpoints for plan quality evaluation, but the infrastructure proposed here applies to general outcome data as well. The authors expect forward evaluation together with intelligent update based on evidence-based learning, which will evolve the clinical practice for improved efficiency, consistency, and ultimately better treatment outcome.
放射治疗计划质量的剂量学方面通常通过剂量体积直方图 (DVH) 终点进行评估和报告。为了临床实用性，通常从 DVH 中提取少量有代表性的数量作为剂量终点来总结计划质量。对于某些标准治疗方法，国家指南通常会使用这些数量的参考值作为接受标准来触发治疗计划审查。另一方面，针对每个机构的治疗处方和规划方法需要根据实践一致性和机构特定经验报告计划质量。本研究的目的是调查和开发一种系统的方法来记录和描述机构特有的计划经验，并利用这些信息来指导计划质量标准的设计。在临床环境中，这种方法将有助于 (1) 提高整体计划质量和一致性，以及 (2) 为回顾性分析检测异常计划行为。
作者提出了一种自我进化的方法，并开发了内部原型软件套件，该套件 (1) 从治疗计划中提取剂量终点，并根据国家标准和机构特定标准对其进行评估，以及 (2) 对剂量终点的统计数据进行进化，并更新机构特定标准。
该方法的有效性已通过前列腺立体定向体部放射治疗病例数据库得到验证。随着更多数据集的积累，不断发展的机构特定标准可以作为计划质量的可靠且稳定的一致性度量，并揭示了比国家标准或预期标准更严格的标准的潜在用途，从而推动实践缩小可接受计划和潜在最优计划之间的差距。
作者通过从机构特定经验中不断发展计划质量标准，提出了一种改进计划质量和一致性的合理方法，补充了国家标准。该方法的有效性已通过前列腺立体定向体部放射治疗 (SBRT) 病例的原型系统得到验证。目前的研究使用直接和间接的 DVH 终点进行计划质量评估，但这里提出的基础设施也适用于一般结果数据。作者期望进行前瞻性评估，并基于循证学习进行智能更新，从而为提高效率、一致性并最终改善治疗效果而不断发展临床实践。
