Intraarterial Ir-192 high-dose-rate brachytherapy for prophylaxis of restenosis after femoropopliteal percutaneous transluminal angioplasty: The prospective randomized Vienna-2-trial radiotherapy parameters and risk factors analysis

Purpose: The aim of the Vienna-a-trial was to compare the restenosis rate o f femoropopliteal arteries after percutaneous transluminal angioplasty (PTA ) with or without intraarterial high-dose-rate (HDR) brachytherapy (BT) usi ng an Ir-192 source. Materials and Methods: A prospective, randomized trial was conducted from 1 1/96 to 8/98, A total of 113 patients (63 men, 50 women), with a mean age o f 71 gears (range, 43-89 years) were included. Inclusion criteria were (I) claudication or critical limb ischemia, (2) de-novo stenosis of 5 cm or mor e, (3) restenosis after former PTA of any length, and (3) no stent implanta tion. Patients were randomized after successful PTA for BT vs. no further t reatment, A well-balanced patient distribution was achieved for the criteri a used for stratification, as there were "de-novo stenosis vs. restenosis a fter former PTA," "stenosis vs. occlusion," "claudication vs. critical limb ischemia" and above these for "diabetes vs, nondiabetes." PTA length was n ot well balanced between the treatment arms: a PTA length of 4-10 cm was se en in 19 patients in the PTA alone group and in 11 patients in the PTA+BT g roup, whereas a PTA length of greater than 10 cm was seen in 35 patients an d 42 patients, respectively. A dose of 12 Gy was prescribed in 3-mm distanc e from the source axis. According to AAPM recommendations, the dose was 6.8 Gy in 5-mm distance (vessel radius + 2 mm), Primary endpoint of the study was femoropopliteal patency after 6 months, Results: PTA and additional BT were feasible and well tolerated by all 57 p ts in this treatment arm, No acute, subacute, and late adverse side effects related to BT were seen after a mean follow up of 12 months (6-24 months) in 107 patients (PTA n = 54; PTA + BT n = 53), Crude restenosis rate at 6 m onths was in the PTA arm 54% vs. 28% in the PTA + BT arm (chi (2) test; p < 0,013. Actuarial estimate of the patency rate was at 6 months 45% vs, 72% (p < 0.001). Comparison of restenosis rates for the different subgroups wit h risk factors (restenosis after former PTA, occlusion and PTA length >10 c m) showed significant decrease of the restenosis rate, if BT was added, Sig nificant reduction was not achieved in diabetes patients. Conclusion: BT after femoropopliteal PTA is feasible and a safe therapeutic option. No BT related morbidity was observed. ii significant reduction of the restenosis rate was obtained in the PTA + BT arm, Subgroup analysis sho wed significant decrease of restenosis rate in the subgroups with restenosi s after former PTA, occlusion and PTA length of greater than 10 cm, With do se escalation and reduction of dose variation by a centering device a furth er significant decrease of restenosis rate can be expected, (C) 2000 Elsevi er Science Inc.