CE-452773-1 PROTON CARDIAC RADIOABLATION FOR REFRACTORY VENTRICULAR TACHYCARDIA: DOSE DISTRIBUTION TO TARGET MYOCARDIUM AND ORGANS AT RISK

Cardiac radioablation has emerged as a novel approach for the treatment of refractory scar-related ventricular tachycardia (VT). Current clinical evidence this is limited to photon treatments. and extracardiac radiation dose distributions in humans treated VT with proton beam therapy have not been previously reported. To evaluate target myocardium organs-at-risk (OAR) intensity modulated (IMPT). Dose volume histograms were analyzed 6 patients (5 males; age 67.7±5.2 years) despite antiarrhythmic drugs catheter ablation who IMPT setting an ongoing single-center first-in-human trial. In each patient, single fraction 30 Gy was prescribed. Among all patients, median Clinical Target Volume 17 cc (range 8.3-64.9 cc) non-target myocardial 285.5 185.1-329 cc). Median maximum voxel 38 35.2-38.9 Gy) while only 4.3% 3.6-7.9%) received ≥20 Gy. Averaged other OARs are shown Table. OARs, percentage total lung receiving ≥10Gy 0.1% 0-5.7%). coronary arteries, left anterior descending max doses ranging from 17.7 27.9 without consequences. These data demonstrate that therapeutic can be delivered low exposure cardiac OARs.