350 - Dosimetric Parameters of the Heart and its Substructures Predicting Survival and Cardiac Events in Lung Cancer Patients after Radiotherapy: A Systematic Review and Meta-Analysis

04:40pm - 04:50pm PT

Room 155/157

Presenter(s)

Jun Wang, MD, PhD - Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei

J. Wang¹, X. Li², Y. Zhao³, C. Wang⁴, and G. Hou⁵; ¹Department of Radiation Oncology, the Fourth Hospital of Hebei Medical University, Shijiazhuang, China, ²The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China, ³The Fourth Hospital Of Hebei Medical University, Shijiazhuang, Hebei, China, ⁴The Fourth Hospital of Hebei Medical University, Shijiazhuang, China, ⁵Cangzhou Hospital of Intergrated Traditional Chinese and Western Medicine, Shijiazhuang, Hebei Province, China

Purpose/Objective(s): Conflicting evidence exists on whether whole heart (WH) and cardiac substructures (CSs) radiation dosimetry predicts survival and cardiac events (CEs) in lung cancer patients. This systematic review aims to synthesize evidence on these associations.

Materials/Methods: This systematic review adhered to PRISMA guidelines and was registered in PROSPERO (CRD42024628884). We conducted a comprehensive search across PubMed, Embase, and Cochrane Library (from inception to October 2024) for studies evaluating cardiac dosimetric parameters in lung cancer patients receiving radiotherapy. Statistical heterogeneity was quantified using I² statistics. A fixed-effects or random-effects model meta-analysis was applied based on the heterogeneity test. STATA version 18 software was used for all analyses.

Results: A total of 72 studies (15,424 patients) were included, assessing 325 unique cardiac dosimetric parameters. Key findings include: Major Adverse Cardiac Events (MACE): No significant dosimetric parameters were found for WH parameters. However, the left anterior descending artery (LAD) V15 (HR: 13.90, 95% CI: 1.23-127.21) was significant for CSs parameters. Arrhythmia: No dosimetric parameters showed significance for WH parameters. Significant associations were observed in CSs parameters, including left atrium (LA) V5, right atrium (RA) Dmax, sinoatrial node (SAN) Dmax, pulmonary vein (PV) V5/V55/V10, and left circumflex artery V35 for atrial arrhythmias; left main coronary artery (LMA) V10 and right coronary artery (RCA) V25 for bradyarrhythmias; LMA V5/V50 for ventricular tachycardia; and RA V60, PV V55 for other supraventricular tachycardia. Ischemic Events: The mean heart dose (MHD) (pooled HR: 1.07, 95% CI: 1.03-1.11) was significant for WH parameters. CSs parameters, including LV Dmean/V60, RV Dmean, and LAD Dmean, also showed significance. Pericardial Effusion: MHD, and heart V5/V35/V55 were significant for WH parameters. For CSs parameters, pericardium (PCA) Dmean/V5/V30/V55 were significant. Survival Outcomes: MHD, heart V2/V5/V15/V30 predicted overall survival for WH parameters. For CSs parameters, LA, RA, the aorta and origin of the coronary arteries, aortic valve, pulmonary artery, SAN, and PCA dosimetric parameters were significant.

Conclusion: To our knowledge, this is the first systematic review describing survival and CEs being associated with WH and CSs dose in lung cancer patients. Regarding MACE, only LAD V15 showed significant results. Additionally, when analyzing different CEs (especially atrial arrhythmias), CSs doses seems to demonstrated greater clinical relevance than WH parameters, reflecting the pathophysiological impact of localized structural damage. For survival outcomes, evidence remains heterogeneous. While MHD retains prognostic value, CSs parameters are increasingly implicated. These findings advance our understanding of radiation-induced cardiac dysfunction and guide potential mitigation strategies.