Intracoronary brachytherapy: past, present, and future.

Abstract

The purpose of intracoronary brachytherapy is to reduce the incidence of lesion recurrence (restenosis) after percutaneous coronary intervention. Its rationale is based on the concept that restenosis is a process of benign tissue proliferation and that locally applied radiation can prevent or attenuate the magnitude of this response. After encouraging results from animal models,1,2⇓ small observational and randomized clinical trials were initiated to demonstrate the feasibility and safety of this unique application of radiation.3–5⇓⇓ Positive findings led to larger randomized trials that demonstrated a powerful treatment effect.6,7⇓ In patients presenting with restenosis within a previously implanted stent, the likelihood of repeat restenosis was reduced by ≈50%. Results of brachytherapy administered to patients undergoing balloon angioplasty alone or at the time of stent implantation have been inconsistent. At this time, brachytherapy is considered to be a standard treatment alternative for selected patients with in-stent restenosis, and it is performed as a component of routine practice in interventional cardiology. See p 2737 Several questions remain unanswered, however, about intracoronary brachytherapy. In particular, does this treatment delay or prevent restenosis? Can it stimulate atherosclerosis elsewhere in the coronary circulation? Does it create the potential for spontaneous coronary rupture or thrombosis? Are there any untoward extra-coronary effects, such as myocardial or pericardial fibrosis? In this issue of Circulation , Grise and colleagues8 provide information to help answer these questions. They report the 5-year clinical outcomes of 55 patients enrolled in …