Institute of Modern Physics, Fudan University, Shanghai, China.
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University, Shanghai, China.
J Appl Clin Med Phys. 2023 Dec;24(12):e14119. doi: 10.1002/acm2.14119. Epub 2023 Aug 11.
Dose to heart substructures is a better predictor for major adverse cardiac events (MACE) than mean heart dose (MHD). We propose an avoidance planning strategy for important cardiac substructures.
Two plans, clinical and cardiac substructure-avoidance plan, were generated for twenty patients. Five dose-sensitive substructures, including left ventricle, pulmonary artery, left anterior descending branch, left circumflex branch and the coronary artery were chosen. The avoidance plan aims to meet the target criteria and organ-at-risk (OARs) constraints while minimizing the dose parameters of the above five substructures. The dosimetric assessments included the mean dose and the maximum dose of cardiac substructures and several volume parameters. In addition, we also evaluated the relative risk of coronary artery disease (CAD), chronic heart failure (CHF), and radiation pneumonia (RP).
Pearson correlation coefficient and R value of linear regression fitting demonstrated that MHD had poor prediction ability for the mean dose of the cardiac substructures. Compared to clinical plans, an avoidance plan is able to statistically significantly decrease the dose to key substructures. Meanwhile, the dose to OARs and the coverage of the target are comparable in the two plans. In addition, it can be observed that the avoidance plan statistically decreases the relative risks of CAD, CHF, and RP.
The substructure-avoidance planning strategy that incorporates the cardiac substructures into optimization process, can protect the important heart substructures, such as left ventricle, left anterior descending branch and pulmonary artery, achieving the substantive sparing of dose-sensitive cardiac structures, and have the potential to decrease the relative risks of CAD, CHF, and RP.
心脏亚结构剂量比平均心脏剂量（MHD）更能预测主要不良心脏事件（MACE）。我们提出了一种重要心脏亚结构回避规划策略。
为 20 名患者生成了两个计划，即临床计划和心脏亚结构回避计划。选择了五个剂量敏感的亚结构，包括左心室、肺动脉、左前降支、左回旋支和冠状动脉。回避计划旨在满足目标标准和危及器官（OAR）限制的同时，最大限度地降低上述五个亚结构的剂量参数。剂量评估包括心脏亚结构的平均剂量和最大剂量以及几个体积参数。此外，我们还评估了冠心病（CAD）、慢性心力衰竭（CHF）和放射性肺炎（RP）的相对风险。
Pearson 相关系数和线性回归拟合的 R 值表明，MHD 对心脏亚结构的平均剂量预测能力较差。与临床计划相比，回避计划能够显著降低关键亚结构的剂量。同时，两个计划中 OAR 剂量和靶区覆盖度相当。此外，可以观察到回避计划在统计学上降低了 CAD、CHF 和 RP 的相对风险。
将心脏亚结构纳入优化过程的亚结构回避规划策略，可以保护左心室、左前降支和肺动脉等重要心脏亚结构，实现对剂量敏感的心脏结构的实质性保护，并有可能降低 CAD、CHF 和 RP 的相对风险。
