BETA-Washington Radiation for In-Stent Restenosis Trial. A trial evaluating the safety and efficacy of beta-radiation—90Yt—in preventing in-stent restenosis of a previously occluded coronary artery managed by stenting Primary endpoints MACE up to 2 years Conclusion Beta-radiation—90Yt—as adjunct in patients with ISR decreased angiographic and clinical restenosis of implanted stents