Authors' objectives: The aim of this study was to assess the safety, effectiveness, and cost-effectiveness of using localized intracoronary radiation therapy in inhibiting in-stent restenosis following revascularization procedures. These will be compared to revascularization of in-stent restenosis without the concomitant use of radiation therapy.

Authors' results and conclusions: Patients in the studies underwent revascularization procedures (procedures to reopen the vessels) before receiving intracoronary radiation and anti-platelet medication to prevent thrombosis after the procedure. Only one study had a three-year follow-up. None of the other studies exceeded 12 months follow-up. Compared to patients who did not receive radiation, patients who received gamma or beta radiation had significantly lower rates of major adverse events (combined rate of heart attack, revascularization procedures and death) at six to 12-month follow-up. Intracoronary radiation significantly reduced the restenosis rates and the rates of revascularization of the radiated site at six to nine-month follow-up, but did not have any significant effect on the rate of heart attack or death. There was a significant increase in the restenosis and revascularization rates in the radiated group between six and 12 months. However, one study showed that the reduction in the in-stent restenosis rate was still significant at three-year follow-up. Reported complications of intracoronary radiation included : - Restenoses of the edges outside of the irradiated segment. - Late narrowing of the vessel and late total occlusion of the irradiated area. - Late thrombosis (formation of blood clot inside the vessel) was associated with an increased risk of heart attack in some studies - Stopping the anti-platelet drug or placing new stents at the time of intracoronary radiation increased the risk of late thrombosis. Intracoronary radiation using radioactive stents was not as effective as radioactive ribbons or wires.

Authors' recommendations: - Intracoronary gamma or beta radiation using catheter-based delivery systems and radioactive ribbons is safe and effective in the short term as an adjunct therapy in preventing in-stent restenosis. - Its benefit has been lessened by late thrombosis, which may increase the risk of heart attacks. - Long-term anti-platelet therapy, and limitation of the number of new stents placed at the time of radiation may reduce the risk of late thrombosis. - Restenosis at the margins of the irradiated segment is another concern. - The role of intracoronary radiation in preventing restenosis in new stenosis has not been established. - The long-term safety, effectiveness and cost-effectiveness of intracoronary radiation remain unknown at this time. - The relative effectiveness of Intracoronary radiation versus competing technologies, particularly drug eluting stents, has not been established.

Project Status: Completed

Year Published: 2001

URL for published report: http://www.health.gov.on.ca/english/providers/program/mas/tech/reviews/pdf/rev_icrad_120101.pdf

URL for additional information: http://www.hqontario.ca/evidence/publications-and-ohtac-recommendations/ohtas-reports-and-ohtac-recommendations/intracoronary-radiation

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Canada

Organisation Name: Medical Advisory Secretariat

Contact Address: Medical Advisory Secretariat, 20 Dundas Street West, 10th Floor, Toronto, ON M5G 2N6 CANADA. Tel: 416-314-1092l; Fax: 416-325-2364;

Contact Name: MASinfo.moh@ontario.ca

Contact Email: MASinfo.moh@ontario.ca

Copyright: <p>Medical Advisory Secretariat, Ontario Ministry of Health and Long-Term Care</p>