Bowen Jones Sarah, Marchant Tom, Saunderson Chris, McWilliam Alan, Banfill Kathryn
Radiotherapy Related Research, The Christie NHS Foundation Trust, Manchester, UK.
Division of Cancer Sciences, University of Manchester, Manchester, UK.
J Med Imaging Radiat Oncol. 2024 Dec;68(8):974-986. doi: 10.1111/1754-9485.13737. Epub 2024 Sep 3.
Normal tissue tolerance dose limits to the heart have been established to reduce the risk of radiation-induced cardiac disease (RICD). Dose constraints have been developed based on either the mean dose delivered to the whole heart (MHD) or the dose delivered to a specific volume, for example, volume of heart receiving equal to or greater than 30 Gy (V30). There is increasing evidence that the impact of thoracic radiation on cardiac morbidity and mortality has been underestimated. Consequently, there is a need to reduce the dose delivered to the heart in radical radiotherapy treatment planning. The pathophysiology of RICD may relate to dose to specific cardiac substructures (CS) rather than the traditionally observed MHD for common toxicities. The MHD or V30 Gy threshold dose rarely represents the true dose delivered to individual CS. Studies have shown the dose to specific areas may be more strongly correlated with overall survival (OS). With advances in modern radiotherapy techniques, it is vital that we develop robust, evidence-based dose limits for CS, to fully understand and reduce the risk of RICD, particularly in high-risk populations with cardiac risk factors. The following review will summarise the existing evidence of dose limits to CS, explain how dose limits may vary according to different disease sites or radiation techniques and propose how radiotherapy plans can be optimised to reduce the dose to these CS in clinical practice.
已确定心脏的正常组织耐受剂量限值，以降低放射性心脏病（RICD）的风险。剂量限制是基于输送到整个心脏的平均剂量（MHD）或输送到特定体积的剂量制定的，例如，接受等于或大于30 Gy剂量的心脏体积（V30）。越来越多的证据表明，胸部放疗对心脏发病率和死亡率的影响被低估了。因此，在根治性放射治疗计划中需要降低输送到心脏的剂量。RICD的病理生理学可能与特定心脏亚结构（CS）的剂量有关，而不是传统上观察到的常见毒性的MHD。MHD或V30 Gy阈值剂量很少代表输送到个体CS的真实剂量。研究表明，特定区域的剂量可能与总生存期（OS）更密切相关。随着现代放疗技术的进步，至关重要的是我们要为CS制定强有力的、基于证据的剂量限值，以充分理解并降低RICD的风险，特别是在有心脏危险因素的高危人群中。以下综述将总结CS剂量限值的现有证据，解释剂量限值如何根据不同疾病部位或放疗技术而变化，并提出在临床实践中如何优化放疗计划以降低对这些CS的剂量。
