University of New South Wales, South Western Sydney Clinical School, Sydney, Australia; Liverpool and Macarthur Cancer Therapy Centres, Department of Radiation Oncology, Sydney, Australia; Ingham Institute for Applied Medical Research, Sydney, Australia; University of Sydney, Image X Institute, Sydney, Australia.
University of New South Wales, South Western Sydney Clinical School, Sydney, Australia; Liverpool and Macarthur Cancer Therapy Centres, Department of Radiation Oncology, Sydney, Australia; Ingham Institute for Applied Medical Research, Sydney, Australia.
Clin Oncol (R Coll Radiol). 2024 Oct;36(10):642-650. doi: 10.1016/j.clon.2024.07.005. Epub 2024 Jul 20.
Stereotactic ablative body radiotherapy (SABR) is increasingly used for early-stage lung cancer, however the impact of dose to the heart and cardiac substructures remains largely unknown. The study investigated doses received by cardiac substructures in SABR patients and impact on survival.
SSBROC is an Australian multi-centre phase II prospective study of SABR for stage I non-small cell lung cancer. Patients were treated between 2013 and 2019 across 9 centres. In this secondary analysis of the dataset, a previously published and locally developed open-source hybrid deep learning cardiac substructure automatic segmentation tool was deployed on the planning CTs of 117 trial patients. Physical doses to 18 cardiac structures and EQD2 converted doses (α/β = 3) were calculated. Endpoints evaluated include pericardial effusion and overall survival. Associations between cardiac doses and survival were analysed with the Kaplan-Meier method and Cox proportional hazards models.
Cardiac structures that received the highest physical mean doses were superior vena cava (22.5 Gy) and sinoatrial node (18.3 Gy). The highest physical maximum dose was received by the heart (51.7 Gy) and right atrium (45.3 Gy). Three patients developed grade 2, and one grade 3 pericardial effusion. The cohort receiving higher than median mean heart dose (MHD) had poorer survival compared to those who received below median MHD (p = 0.00004). On multivariable Cox analysis, male gender and maximum dose to ascending aorta were significant for worse survival.
Patients treated with lung SABR may receive high doses to cardiac substructures. Dichotomising the patients according to median mean heart dose showed a clear difference in survival. On multivariable analyses gender and dose to ascending aorta were significant for survival, however cardiac substructure dosimetry and outcomes should be further explored in larger studies.
立体定向消融体放射治疗（SABR）越来越多地用于早期肺癌，但心脏和心脏亚结构的剂量影响在很大程度上仍不清楚。本研究调查了 SABR 患者心脏亚结构接受的剂量及其对生存的影响。
SSBROC 是一项澳大利亚多中心、II 期前瞻性 SABR 治疗 I 期非小细胞肺癌的研究。患者于 2013 年至 2019 年在 9 个中心接受治疗。在该数据集的二次分析中，使用先前发表的和本地开发的开源混合深度学习心脏亚结构自动分割工具，对 117 例试验患者的计划 CT 进行了部署。计算了 18 个心脏结构的物理剂量和等效剂量 2（α/β=3）。评估的终点包括心包积液和总生存。使用 Kaplan-Meier 方法和 Cox 比例风险模型分析心脏剂量与生存之间的关系。
接受最高物理平均剂量的心脏结构是上腔静脉（22.5Gy）和窦房结（18.3Gy）。心脏（51.7Gy）和右心房（45.3Gy）接受的物理最高剂量最高。有 3 例患者发生 2 级，1 例患者发生 3 级心包积液。与接受中位数以下平均心脏剂量（MHD）的患者相比，接受中位数以上平均心脏剂量（MHD）的患者生存情况较差（p=0.00004）。多变量 Cox 分析显示，男性和升主动脉最大剂量是生存的显著影响因素。
接受肺 SABR 治疗的患者可能会接受心脏亚结构的高剂量。根据中位数平均心脏剂量对患者进行二分法，显示出生存差异明显。在多变量分析中，性别和升主动脉剂量是生存的显著因素，但心脏亚结构剂量学和结果应在更大的研究中进一步探讨。
