EFFICACY OF BETA-RADIATION IN PREVENTION OF POSTANGIOPLASTY RESTENOSIS - AN INTERIM-REPORT FROM THE BETA ENERGY RESTENOSIS TRIAL

Restenosis remains a major limitation of coronary angioplasty in spite of major advances in techniques and technology. Recent studies have d emonstrated that ionizing radiation may limit the degree of this probl em. Gamma radiation has been shown to be effective in reducing in sten t restenosis in humans, and beta radiation following encouraging resul ts in animals has been shown to be feasible in humans. The objective o f this study was to assess the feasibility of a 5 F non-centered cathe ter to deliver beta radiation emitting seeds to the lesion site post a ngioplasty and its effect an restenosis. Following successful angiopla sty, patients were randomized to treatment with 12. 14 or 16 Gy at the angioplasty site. This was delivered with a 5 F non-centered catheter . Twelve beta radiation emitting seeds (Sr-90/Y) were delivered to an area 3 cm in length to cover the angioplasty site. Angiographic follow -up was performed at 6 months. Baseline and follow-up angiograms were performed by blinded investigators at a core laboratory This interim r eport comprises the first 35 patients to complete 6-month angiographic follow-up. There were no major radiation incidents. Four patients had evidence of angiographic restenosis. The MLD (mm) and percent stenosi s were 0.77 +/- 0.27/72.5 +/-: 8.6 pre angioplasty, 2.08 +/-: 0.4125.7 +/- 9.8 post angioplasty and radiation and 2.05 +/- 0.59/25.7 +/- 19. 8 at follow-up respectively. Conclusion: Beta radiation can be feasibl y and safely delivered post coronary angioplasty with a very encouragi ng reduction of restenosis.