Use of curietherapy in cardiovascular disease. Radiophysics, current results, indications and perspectives

Restenosis is the main limitation of percutaneous angioplasty, especially i n vessels of small diameters such as the coronary arteries, the femoro-popl iteal and tibial-peroneal arteries and the arterio-venous dialysis grafts. The extensive use of stents has not entirely prevented its occurrence, wher eas treating in-stent restenosis gives even more uncertain results. Endovas cular radiotherapy has emerged over the past few years as a promising appro ach to both prevent and cure it. The analogy between the tumour-like cellular proliferation observed in post angioplasty restenosis and tumour processes prompted pioneering works to s tudy the effect of ionising radiations in animal models of arterial resteno sis. The demonstrated feasibility, tolerance and efficacy of this approach lead to test this strategy in humans. The results of 3 recently presented r andomised double-blind trials in the treatment of coronary in stent resteno sis have been so promising that endovascular brachytherapy might now be con sidered the treatment of choice in this indication. Other randomised trials are currently carried out to test whether endovascular brachytherapy may p revent restenosis in coronary and femoro-popliteal arteries as well as in h emodialysis shunts. In the present review, we describe the basics of the biological effects of ionising radiations, the technical modalities to deliver endovascular radia tions, our current knowledge about their effects on the vascular wall and t he restenosis mechanisms, and the results of the first clinical studies. Fi nally, we address the remaining problems in the use of endovascular curieth erapy and question the promises and challenges of its clinical application.