External beam radiation therapy reduces the rate of re-stenosis in patients treated with femoral stenting: results of a randomised study

Background and purpose: To evaluate the feasibility and efficacy of external beam irradiation (EBI) for the prevention of re-stenosis due to neointimal hyperplasia, after percutaneous transluminal angioplasty (PTA) and stent placement of the superficial femoral artery. Patients and methods: A total of 60 patients with the diagnosis of superficial femoral artery stenoses or occlusions due to peripheral arterial obstructive disease underwent PTA and implantation of a self-expandable stent at their superficial femoral artery. After the procedure, patients were randomised and 30 of them received EBI (6 MV photons, total dose 24 Gy in six fractions in 2 weeks), while the rest 30 received no radiation therapy. Results: EBI was technically feasible in all patients, without serious radiation related side effects. Overall, a statistically significant difference was observed in stenosis categories between the two groups at 6 months follow-up (P=0.04). More specifically, significantly more patients in the control group presented with stenosis greater or equal than 70% [EBI group 30% (9/30); control group 66.7% (20/30); P=0.009]. This difference in the percentage of re-stenosis had as a consequence significantly lower re-intervention rates among the patients of the irradiated group [17% (5/30) versus 47% (14/30); P=0.025] during the 6 months follow-up period. We also observed that the irradiated patients had re-stenosis at the stent ends, while the non-irradiated had re-stenosis at the stent ends and the lumen. Three of the irradiated patients, who discontinued the anti-platelet treatment, have shown thrombosis of the irradiated artery during the first month from the completion of the treatment. Conclusions: It is our belief that EBI is a feasible, safe and effective method for the prevention of neointimal hyperplasia at the superficial femoral artery. Further studies are deemed necessary to optimise the radiotherapy schedule