Predictive Value of Changes in Basal Myocardial F-Fluorodeoxyglucose Uptake for Cardiotoxicity in Patients With Locally Advanced Esophageal Cancer Receiving Definitive Radiation Therapy.

Purpose: To investigate the predictive value of changes in segmental myocardial F-fluorodeoxyglucose (FDG) uptake for major adverse cardiac events (MACEs) in patients with locally advanced esophageal cancer undergoing definitive radiation therapy (RT).

Methods And Materials: Between August 2012 and January 2019, 482 patients with stages II and III esophageal cancer from 2 institutions were enrolled and divided into the training (n = 285) and external validation (n = 197) cohorts. All patients underwent F-FDG positron emission tomography within 1 week before treatment and within 3 months of treatment. Myocardial delineation was performed using the Carimas software based on the American Heart Association 17-segment model and was automatically divided into basal, middle, and apical regions. The main endpoint was the occurrence of MACEs, including unstable angina, myocardial infarction, coronary revascularization, hospitalization for heart failure or urgent visits, and cardiac death. Analyses included competing risk and Cox regression. Model performance was assessed using the area under the receiver operating characteristic curve and Brier score.

Results: Thirty-four patients (11.9%) developed MACEs at a median follow-up of 78 months. The basal region (median, 19.44 Gy) of the myocardium received the highest radiation dose, followed by the middle (median, 13.02 Gy) and apical regions (median, 9.32 Gy). Multivariate analysis showed that the change ratio in pretreatment and posttreatment basal myocardial mean standardized uptake value (SUV) remained significant after adjusting for age, pre-existing cardiac disease, and dosimetric parameters. The area under the receiver operating characteristic curves and Brier scores demonstrated favorable predictive accuracies of models integrating variables with significant differences in the multivariate analysis when predicting MACEs in the training and validation cohorts.

Conclusions: The basal change ratio of mean SUV was an independent predictor of MACEs in patients with locally advanced esophageal cancer receiving definitive RT. Changes in basal myocardial FDG uptake are promising biomarkers for predicting radiation-induced cardiotoxicity.