Comparison of the angiographic outcomes after beta versus gamma vascular brachytherapy for treatment of in-stent restenosis

This study was designed to compare the angiographic outcomes of beta versus gamma vascular brachytherapy (VBT). We reviewed the angiographic results of 636 lesions (212 that underwent beta and 212 that underwent gamma VBT, and 212 that received placebo) with native coronary in-stent restenosis matched for lesion length, vessel size, preprocedure minimum lumen diameter (MLD), and time to angiographic follow-up in the various randomized clinical trials and studies. Baseline lesion complexity was similar in these 3 groups. Final MLD was smaller in the beta VBT group than in the gamma VBT or placebo group. At follow-up, beta and gamma VBT significantly reduced both angiographic restenosis (34.4% for beta VBT, 26.4% for gamma VBT, and 50.9% in the placebo group; p <0.0001) and recurrent lesion length (9.2 mm for beta VBT, 8.4 mm for gamma VBT, and 15.5 mm placebo, p <0.0001) compared with placebo. Gamma VBT was associated with a greater reduction in restenosis outside the stent than beta VBT. By multivariable analysis, independent angiographic predictors of treated segment restenosis included beta or gamma VBT, lesion length, and vessel size. In matched lesions, beta and gamma VBT achieved similar reductions in treated segment restenosis and recurrent lesion length compared with placebo.