FEASIBILITY OF INTRACORONARY BETA-IRRADIATION TO REDUCE RESTENOSIS AFTER BALLOON ANGIOPLASTY - A CLINICAL PILOT-STUDY

Background With the aim of decreasing the incidence of restenosis afte r coronary balloon angioplasty, we developed a technique of intracoron ary beta-irradiation using an endoluminally centered pure metallic Y-9 0 source. The purpose of the present study was to evaluate the clinica l 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; me an age, 71+/-5 years) underwent intracoronary beta-irradiation immedia tely after a conventional percutaneous transluminal coronary angioplas ty (PTCA) procedure. The PTCA/irradiation procedure was technically fe asible in all attempted cases, and the delivery of the 18 Gy dose was accomplished without complications. In 4 patients, the intervention wa s completed through intra-arterial stent implantation because of disse ction induced by the initial PTCA. During the follow-up period of 178/-17 days (range, 150 to 225 days), no complication occurred that coul d be attributed to radiation therapy. No aneurysm or angiographically detectable thrombus was observed in any of the irradiated arterial seg ments. The clinical event rate (4 of 15 patients underwent further tar get 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. Concl usions This early experience demonstrates that our approach is feasibl e, and no side effects attributable to radiation were noted during a 6 -month period of follow-up. Whether higher doses of beta-irradiation w ill favorably affect post-PTCA restenosis in patients must await furth er evaluation.