Radiation therapy to inhibit restenosis: Early clinical results

Background: Although several early trials indicate that treatment of resten osis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The objective of this report is to document angiographic and clinical outcome 3 years after treatment of rest enosis of stented coronary; arteries with catheter-based iridium-192 (Ir-19 2). Methods: A double-blind, randomized tri;li compared Ir-192 with placebo sou rces in patients with previous restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to Ir-192 a nd 29 to placebo. Results: At 3-year follow-up, target-lesion revascularization was significa ntly lower in the Ir-192 group (15.4% vs. 48.3%; p < 0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in Ir-192 patients (33% vs. 64%; p < 0.05). In a subgroup of patients with 3-year an giographic follow-up not subjected to target-lesion revascularization by th e 6-month angiogram, the mean minimal luminal diameter between 6 months and 3 years decreased from 2.49 +/- 0.81 mm to 2.12 +/- 0.73 mm in Ir-192 pati ents, but was unchanged in placebo patients. Conclusions: The early clinical benefits observed after treatment of corona ry restenosis with Ir-192 appear durable at late follow-up. Angiographic re stenosis continues to be significantly reduced in Ir-192-treated patients, but a small amount of late loss was observed between the 6-month and 3-year follow-up time points. No events occurred in the Ir-192 group to suggest m ajor untoward effects of vascular radiotherapy. At 3-year follow-up, vascul ar radiotherapy continues to be a promising new treatment for restenosis.