External beam radiation to prevent restenosis after superficial femoral artery balloon angioplasty.

BACKGROUND Femoropopliteal percutaneous transluminal angioplasty (PTA) remains limited by restenosis. Although vascular brachytherapy may be effective in reducing restenosis, external beam radiation would be more practical to administer after PTA. METHODS AND RESULTS After femoropopliteal PTA without stent placement, 99 patients were randomly assigned to 0 Gy (placebo; n=24), 7 Gy (n=24), 10.5 Gy (n=26), or 14 Gy (n=25) of external beam radiation of the PTA site (with a 3-cm margin at both extremities) in 1 session 24 hours after PTA. The primary end point was minimum lumen diameter on quantitative angiography 1 year after PTA. One year after PTA, the mean minimum lumen diameter was 1.92, 1.64, 1.92, and 2.91 mm, respectively, for the 0-, 7-, 10.5-, and 14-Gy groups (P=0.0072 for 0 versus 14 Gy). Mean luminal loss was 1.14, 1.27, 1.08, and 0.14 mm, respectively, for the 4 groups (P=0.0072 for 0 versus 14 Gy). Restenosis >50% was present in 50%, 65%, 48%, and 25% of patients, respectively, for the 0-, 7-, 10.5-, and 14-Gy groups (P=0.072). At 18 months, repeated revascularizations were required in 25% of patients in the 0-Gy group versus 12% of patients in the 14-Gy group (P=0.24). CONCLUSIONS A single session of external beam radiation of 14 Gy of the femoropopliteal angioplasty site significantly reduces restenosis at 1 year.