Encore.

Headline: Stereotactic body radiation (SBRT) is coming to an ACLS algorithm near you.

The Study: Heart SBRT made such a splash with a “n” of 5, you knew there had to be an encore. ENCORE-VT (LBA4) was a small, albeit bigger, phase 1/2 trial of 19 patients with refractory ventricular tachycardia (VT) receiving 25 Gy x 1 to the arrhythmogenic scar. Impressively, 18/19 patients had a significant reduction in VT burden at 6 months, and 16/19 maintained a low burden all the way out at 12 months. Two patients experienced adverse events that were “probably” related to radiation, pericarditis (ok, fine) and a gastropericardial fistula (good luck blaming this one on GERD). Two things here. First, don’t be fooled into thinking that cardiac radioablation is akin to lung SBRT. While the technical aspects may appear fairly straightforward to most rad oncs, the target volume ain’t, being highly dependent on electrophysiology (read: highly dependent on a qualified cardiologist). Which brings us to number two: we should all be as leery of cardiologists performing solo SBRT as we should be of rad oncs threading catheters into the atrium.

TBL: ENCORE-VT lays groundwork for a promising synergism of the knowledge and experience of rad oncs and cardiologists in larger trials of cardiac radioablation. | Robinson, ASTRO 2019