Interpretation:

Among patients with in-stent restenosis, beta-radiation using 90Sr/90Y was associated with a reduction in the primary endpoint of clinically driven target vessel revascularization by 8 months. Likewise, binary angiographic restenosis was reduced. In stent restenosis remains a significant clinical problem with more than 100,000 patients treated for this condition each year. Previous trials have demonstrated that gamma radiation is effective in the treatment of in-stent restenosis with significant reductions in target vessel revascularization noted in several clinical trials. The START investigators have demonstrated that beta radiation also effectively reduces target vessel revascularization in patients with in-stent restenosis. An important consideration is that despite radiation, binary angiographic restenosis was still observed in > 28% of these patients. If the preliminary results from the drug-eluting stents are confirmed in larger trials, the role of radiation therapy in treating patients with in-stent restenosis will need to be reevaluated and compared with this new modality. If drug eluting stents are effective, the incidence of in stent restenosis will likewise be reduced. Very late follow-up of these patients remains to be reported at this time.