Intracoronary brachytherapy with ??-radiation for the treatment of long diffuse in-stent restenosis

In Brief Objective To assess the efficacy of intracoronary brachytherapy with β-radiation (90Sr/90Y) for the treatment of long diffuse in-stent restenosis (ISR). Methods As recurrent ISR depends on intimal injury after coronary angioplasty, long in-stent restenotic lesions were defined as lesions with a treatment length >26 mm (lesion length >20 mm plus a treatment margin of 3 mm at each end). Seventy-eight patients with long ISR were treated at our institution with β-brachytherapy after coronary angioplasty. Patients were irradiated with either an approximate dose of 12 Gy at 1 mm vessel wall depth or with 18 Gy at 1 mm vessel wall depth. Clinical follow-up was available for 69 patients and angiographic follow-up for 65 patients. Late lumen loss (LLL), binary restenosis (stenosis >50%), target lesion revascularization (TLR) and major adverse cardiac events (MACE) were assessed for a follow-up time of 6.6±2.2 months. Results Mean interventional treatment length was 46±18 mm. TLR was performed in all 23 patients with binary restenosis (33%). Death of cardiac cause was reported for two patients, one of whom did not undergo TLR. Thus, overall MACE rate was 35%. Recurrent ISR was significantly more frequent in patients with geographic miss. Comparison of the different radiation dose regimens revealed significantly lower LLL in patients irradiated with the higher dose (0.20±0.68 mm compared with 0.65±0.96 mm, P=0.03). Conclusion Intracoronary brachytherapy with β-radiation (90Sr/90Y) is a safe and effective therapeutic option for the reduction of recurrent ISR in long diffuse lesions. We recommend a high-dose irradiation with 18 Gy at 1 mm vessel wall depth. Intracoronary beta-brachytherapy with the (90Sr/90Y)-source was found to be a safe and effective therapeutic option for the reduction of recurrent in-stent restenosis in long diffuse lesions (> 26 mm) inatotal of 69 patients (35% major adverse cardiac events). Comparison of two different radiation dose regimens revealed significantly lower late lumen loss in patients irradiated with the higher dose. In order to achieve optimal outcome we recommend a high dose irradiation with 18 Gy at 1 mm vessel wall depth.