Intracoronary radiotherapy for prevention of restenosis after percutaneouscoronary interventions

More than 50 different pharmacological and mechanical interventions have be en tested to date for prevention of vascular restenosis without success. In tracoronary radiotherapy is the first one showing promise of significantly attenuating neointimal proliferation, causing positive vascular remodelling and thus inhibiting restenosis. This promising modality has moved from ani mal experiments via safety and feasibility testing into the phase of clinic al trials of efficacy in large numbers of patients. While ongoing research continues to search for new sources and delivery techniques, currently avai lable technology is being optimized. The randomized clinical trials conduct ed to date have shown consistently a reduction of target site restenosis ra tes by 55-79%. Lower incidence of major adverse cardiac events after radiot herapy has also been demonstrated, primarily as a result of reduction in ta rget site and target vessel revascularization rates. However, experimental and clinical research has identified two major complications of this approa ch: stenosis at the ends of the radiation zone ('edge effect' or 'candywrap per') as well as late thrombosis (beyond 30 days after intervention) of the angioplasty or stent site. If these two adverse effects can be minimized, intracoronary radiotherapy may prove to be a major breakthrough in percutan eous coronary interventions.