Department of Radiation Oncology, University of California, Los Angeles, USA; Institut Paoli Calmettes, Marseille, France.
Department of Radiation Oncology, University of California, Los Angeles, USA.
Radiother Oncol. 2018 Nov;129(2):319-325. doi: 10.1016/j.radonc.2018.08.009. Epub 2018 Aug 30.
BACKGROUND/PURPOSE: Stereotactic-magnetic-resonance-guided-online-adaptive-radiotherapy (SMART) is a promising tool for pancreas stereotactic-body-radiotherapy. Our online-adaptive-radiotherapy (On-ART) process relies on daily image overview by the managing radiation-oncologist, who determines the need for creating a predicted plan if significant interfractional anatomical changes are noted. Predicted plans are achieved through applying the baseline plan on deformed and manually adjusted contours based on daily imaging. If the dose to the target volume or organs-at-risk (OARs) violate constraints, an adapted plan is generated and delivered for treatment. In-depth review of daily images and deformed contours is limited by time and inter-observer variations. This study evaluates the reliability of our On-ART decision-making process. All fractions retrospectively underwent a predicted plan for off-line decision-making to adapt (Off-ART). Decisions to adapt were compared using On-ART and Off-ART approaches.
MATERIAL/METHODS: Thirty-five sets of daily images were analyzed from seven patients who underwent five fractions of SMART. Each OAR was fully re-contoured off-line by the same physician for each fraction. Off-ART decision was re-evaluated for each fraction.
N = 14/35 fractions were adapted based on On-ART decision-making versus N = 25/35 with Off-ART. The concordance between On-ART and Off-ART decision was 87.5% for the 16 fractions using a predicted plan online and 42% for the 19 fractions using only visual image review for On-ART decision-making.
Daily-image visual review is not reliable to determine benefit or not for adaptive radiation-therapy. Online predicted plan, based on deformed and manually adjusted contours, should be generated for every fraction that is delivered using SMART in order to reliably optimize treatment plans daily.
背景/目的：立体定向磁共振引导在线自适应放疗（SMART）是一种很有前途的胰腺立体定向体部放疗工具。我们的在线自适应放疗（On-ART）流程依赖于主治放射肿瘤学家的日常图像综述，如果发现明显的分次间解剖变化，就需要确定是否需要创建预测计划。预测计划是通过将基线计划应用于基于日常图像的变形和手动调整的轮廓来实现的。如果靶区或危及器官（OARs）的剂量违反约束，则生成并提供适应性计划进行治疗。对日常图像和变形轮廓的深入审查受到时间和观察者间差异的限制。本研究评估了我们的 On-ART 决策过程的可靠性。所有分次均回顾性地进行预测计划以进行离线决策（Off-ART）。使用 On-ART 和 Off-ART 方法比较了适应性决策。
材料/方法：分析了 7 名患者的 35 组每日图像，这些患者接受了 SMART 的 5 个分次照射。每个 OAR 都由同一位医生在每个分次中完全重新进行轮廓勾画。对每个分次重新评估了 Off-ART 决策。
基于 On-ART 决策有 N = 14/35 分次进行了适应性治疗，而基于 Off-ART 决策有 N = 25/35 分次进行了适应性治疗。对于 16 个分次，使用在线预测计划的 On-ART 和 Off-ART 决策之间的一致性为 87.5%，而仅使用 On-ART 决策的视觉图像审查的 19 个分次的一致性为 42%。
日常图像的视觉审查不足以确定自适应放疗的获益情况。为了每天可靠地优化治疗计划，对于使用 SMART 进行的每一分次，都应生成基于变形和手动调整的轮廓的在线预测计划。
