Feasibility of Intracoronary β-Irradiation to Reduce Restenosis After Balloon Angioplasty

Abstract

Background With the aim of decreasing the incidence of restenosis after coronary balloon angioplasty, we developed a technique of intracoronary β-irradiation using an endoluminally centered pure metallic 90 Y source. The purpose of the present study was to evaluate the clinical feasibility and safety profile of this approach with a dose of 18 Gy delivered to the inner arterial surface. Methods and Results Between June 21 and November 15, 1995, fifteen patients (6 women and 9 men; mean age, 71±5 years) underwent intracoronary β-irradiation immediately after a conventional percutaneous transluminal coronary angioplasty (PTCA) procedure. The PTCA/irradiation procedure was technically feasible in all attempted cases, and the delivery of the 18 Gy dose was accomplished without complications. In 4 patients, the intervention was completed through intra-arterial stent implantation because of dissection induced by the initial PTCA. During the follow-up period of 178±17 days (range, 150 to 225 days), no complication occurred that could be attributed to radiation therapy. No aneurysm or angiographically detectable thrombus was observed in any of the irradiated arterial segments. The clinical event rate (4 of 15 patients underwent further target lesion revascularization) and the angiographic follow-up (6 of 15 patients had a >50%-diameter stenosis at the previously treated site) did not suggest a marked impact on the expected restenosis rate. Conclusions This early experience demonstrates that our approach is feasible, and no side effects attributable to radiation were noted during a 6-month period of follow-up. Whether higher doses of β-irradiation will favorably affect post-PTCA restenosis in patients must await further evaluation.