Radiotherapy center, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, China.
Guangzhou Medical University, Guangzhou, China.
Strahlenther Onkol. 2021 Mar;197(3):177-187. doi: 10.1007/s00066-020-01631-x. Epub 2020 Jun 2.
This study aimed to evaluate the quality of locally advanced nasopharyngeal carcinoma (NPC) radiotherapy plans generated by the automated planning module of a commercial treatment planning system (TPS).
Data of 30 patients with locally advanced NPC were retrospectively investigated. For each patient, volumetric modulated arc therapy (VMAT) plans with double arcs were generated manually by experienced physicists and automatically in the Pinnacle Auto-Planning module (Philips Medical Systems, Fitchburg, WI, USA). The anatomic distance between the second clinical target volume (CTV) and the pons of the brainstem, and the T category of disease were factored into the evaluation. Dosimetric verification was evaluated in terms of gamma pass rate. Target coverage, sparing of organs at risk (OARs), and monitor units were evaluated and compared between the manual and automatic VMAT plans.
Not all treatment plans fully met the dose objectives for planning target volumes (PTVs) and OARs, particularly in T4 patients. Overall, automatic VMAT provides a comparable or superior plan quality to manual VMAT in most cases. In stratified analysis, plan quality is mainly independent on T category but is also affected by anatomic distance. If the anatomic distance is less than 5 mm, the automatic VMAT plan quality is equal or even inferior to manual VMAT performed by experienced physicists. Conversely, if the anatomic distance is greater than 5 mm, the automatic VMAT plan quality is superior to manual VMAT. Gamma pass rates for quality assurance are similar between manual and automatic VMAT plans for the former case, but significantly higher in automatic VMAT for the latter.
The selection of manual versus automatic VMAT planning in locally advanced NPC should be made individually based on the anatomic distance, rather than blindly and habitually, since automatic VMAT is not good enough to completely replace manual VMAT.
本研究旨在评估商业治疗计划系统（TPS）自动计划模块生成的局部晚期鼻咽癌（NPC）放疗计划的质量。
回顾性分析 30 例局部晚期 NPC 患者的数据。对于每位患者，由经验丰富的物理学家手动生成双弧容积调强弧形治疗（VMAT）计划，并在 Pinnacle Auto-Planning 模块（美国菲尼克斯医疗系统公司，菲奇堡，威斯康星州）中自动生成。将第二临床靶区（CTV）与脑桥之间的解剖距离和疾病 T 分期作为评估因素。通过伽马通过率评估剂量验证。评估并比较了手动和自动 VMAT 计划的靶区覆盖、危及器官（OAR）保护和监测单位。
并非所有治疗计划都完全满足计划靶区（PTV）和 OAR 的剂量目标，特别是在 T4 患者中。总体而言，在大多数情况下，自动 VMAT 提供了与手动 VMAT 相当或更优的计划质量。分层分析表明，计划质量主要独立于 T 分期，但也受解剖距离的影响。如果解剖距离小于 5mm，则自动 VMAT 计划质量与由经验丰富的物理学家进行的手动 VMAT 相当甚至更差。相反，如果解剖距离大于 5mm，则自动 VMAT 计划质量优于手动 VMAT。在前一种情况下，手动和自动 VMAT 计划的质量保证伽马通过率相似，但在后一种情况下，自动 VMAT 的伽马通过率明显更高。
在局部晚期 NPC 中，应根据解剖距离个体化选择手动与自动 VMAT 计划，而不是盲目和习惯性地选择，因为自动 VMAT 还不足以完全替代手动 VMAT。
