Serial volumetric intravascular ultrasound analysis of the efficacy at beta irradiation in preventing recurrent in-stent restenosis

We compared postinterventon and follow-up intravascular ultrasound findings of 25 patients from the beta-Washington Radiation for InStent restenosis Trial (in which all patients received radiation) and 75 patients from the Washington Radiation for InStent restenosis Trial (in which patients were randomized to gamma irradiation). The decrease in lumen volume was similar for beta versus gamma and less in both beta versus placebo and gamma versus placebo; the increase in intimal hyperplasia volume was similar for beta versus gamma and greater in both beta versus placebo and gamma versus placebo.