[Intracoronary radiation therapy in controlled and open clinical trials with afterloading systems and "hot" balloon catheters. Analysis of 6,692 patients].
The prevention and treatment of a restenosis, which occurs in ca. 30% of the cases following balloon dilatation of coronary stenoses, using intravascular radiation relies on the inhibition of proliferation that is inherent in every radiation therapy. The analysis is based on 6,692 patients assigned to either a control group (1,717 patients) or to radiation therapy (4,975 patients) in 41 studies. A total of 14 placebo-controlled, randomized and 27 open trials have been completed: 22 regarding in-stent restenosis, ten regarding de-novo stenosis (or restenosis without a stent) as strict inclusion criteria, and nine with all types of stenoses. For in-stent restenoses, vessel size as defined for inclusion was between 2.0 mm and 5.5 mm, stenosis length between 10 mm and 80 mm. In all trials with in-stent restenosis, the primary endpoints were reached; the restenosis rate in the longest coronary segment analyzed was between 45% and 100% in the control groups and between 7.7% and 53.5% in the brachytherapy groups. The respective values for the TVR were between 24.1% and 80% in the control groups and between 2.0% and 41.7% in the brachytherapy groups. In the control groups, MACE was between 25.9% and 80%; it was between 2.0% and 41.7% in the brachytherapy groups. Attaining results for de-novo stenoses was problematic due to "geographic miss" apparently playing a larger role in these cases; but when taking this into consideration, good results were also attained. The known limitations due to late stent thromboses (4-15% in older trials) were to the most part eliminated by administration of clopidogrel for 1 year and the limitations due to the "edge effect" by the application of longer radiation sources. With antiproliferative coated stents as treatment for de-novo stenoses, we can count on intracoronary brachytherapy losing significance in this area. But for in-stent restenoses, intracoronary brachytherapy is the only evidence-based interventional form of therapy.
Silber
Sigmund
S
Klinik Dr. Müller, München. silber@med.de
D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D001610:Beta Particles; D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods; D002986:Clinical Trials as Topic; D000077144:Clopidogrel; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000517:prevention & control* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D005720:Gamma Rays; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage; D011879:Radiotherapy Dosage; D016032:Randomized Controlled Trials as Topic; D015607:Stents; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D013997:Time Factors
D010919:Placebos; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine