Mir Romaana, Groom Nicki, Mistry Hitesh B, Wilson Elena, Faivre-Finn Corinne
National Radiotherapy Trials Quality Assurance (RTTQA) Group, Mount Vernon Cancer Centre, UK.
Mount Vernon Cancer Centre, Northwood, UK.
Clin Transl Radiat Oncol. 2022 Dec 13;39:100560. doi: 10.1016/j.ctro.2022.100560. eCollection 2023 Mar.
Radiotherapy quality assurance (QA) is integral to radiotherapy delivery. Here we report comprehensive contouring, dosimetry, and treatment delivery QA, describe protocol compliance, and detail the impact of protocol variations on acute grade ≥3 toxicity, progression free survival (PFS), and overall survival (OS) in the phase III CONVERT trial.
MATERIALS/METHODS: Radiotherapy planning data from one hundred randomly selected patients were requested. Members of the CONVERT Trial Management Group (TMG) recontoured the heart, lung, and spinal cord organs at risk (OAR) according to the trial guideline. The existing radiotherapy plan were re-applied to the new structures and the new dosimetric data were recollected. Compliance with radiotherapy QA components were recorded and radiotherapy QA components were pooled into protocol variations: acceptable, acceptable variation, and unacceptable variation. Univariable analysis with a Cox proportional hazards model established the relationship between protocol variations and patient outcome.
Ninety-three cases were submitted for retrospective radiotherapy QA review. Demographics of the radiotherapy QA cohort (n=93) matched the non-QA (n=450) cohort. 97.8% of gross tumour volume (GTV) contours were protocol compliant. OAR contours were non-compliant in 79.6% instances of the heart, 37.6% lung, and 75.3% spinal cord. Of the non-compliant heart contours, 86.5% and 2.7% had contours caudal and cranial to the protocol-defined heart borders. 10.8% did not include the pericardial sac and 2.7% did not include the anterior aspect of the pericardium. Eleven (11.8%) submissions exceeded protocol-defined dosimetric heart constraints; six of which were only noted on the application of protocol-compliant contours. Unacceptable variations were not associated with an increase in grade 3 toxicity (p=0.808), PFS (p=0.232), or OS (p=0.743).
Non-protocol compliant heart contours were associated with increased dose delivered to the heart OAR, with 11.8 % of submitted heart structures exceeding protocol-defined constraints. In this QA cohort of patients with small cell lung cancer, unacceptable variations were not associated with acute grade ≥3 toxicity, PFS, or OS. Radiotherapy QA remains the cornerstone of high-quality radiotherapy delivery and should be embedded into clinical trial and non-clinical trial practice; clinical trials should report standardised radiotherapy QA parameters alongside trial outcomes.
放射治疗质量保证（QA）是放射治疗实施过程中不可或缺的一部分。在此，我们报告了全面的轮廓勾画、剂量测定和治疗实施质量保证情况，描述了方案依从性，并详细阐述了方案差异对III期CONVERT试验中≥3级急性毒性、无进展生存期（PFS）和总生存期（OS）的影响。
材料/方法：我们要求提供100例随机选择患者的放射治疗计划数据。CONVERT试验管理组（TMG）的成员根据试验指南对心脏、肺和脊髓等危及器官（OAR）进行了重新轮廓勾画。将现有的放射治疗计划应用于新的结构，并重新收集新的剂量测定数据。记录放射治疗质量保证各组成部分的依从情况，并将放射治疗质量保证各组成部分归纳为方案差异：可接受、可接受差异和不可接受差异。采用Cox比例风险模型进行单变量分析，确定方案差异与患者预后之间的关系。
93例病例被提交进行回顾性放射治疗质量保证审查。放射治疗质量保证队列（n = 93）的人口统计学特征与非质量保证队列（n = 450）相匹配。97.8%的大体肿瘤体积（GTV）轮廓符合方案要求。在心脏轮廓中，79.6%不符合方案要求；在肺部轮廓中，37.6%不符合方案要求；在脊髓轮廓中，75.3%不符合方案要求。在不符合方案要求的心脏轮廓中，86.5%和2.7%的轮廓分别位于方案定义的心脏边界的尾侧和头侧。10.8%未包括心包囊，2.7%未包括心包的前部。11份（11.8%）提交的资料超出了方案定义的心脏剂量限制；其中6份仅在应用符合方案要求的轮廓时才被注意到。不可接受的差异与3级毒性增加（p = 0.808）、PFS（p = 0.232）或OS（p = 0.743）无关。
不符合方案要求的心脏轮廓与心脏OAR所接受的剂量增加有关，提交的心脏结构中有11.8%超出了方案定义的限制。在这个小细胞肺癌患者的质量保证队列中，不可接受的差异与≥3级急性毒性、PFS或OS无关。放射治疗质量保证仍然是高质量放射治疗实施的基石，应纳入临床试验和非临床试验实践中；临床试验应在报告试验结果的同时报告标准化的放射治疗质量保证参数。
