Feasibility and safety of beta irradiation in human coronary arteries.

We have developed a technique of endoluminally centred endovascular beta irradiation aimed at preventing restenosis after PTCA. The source consists of a pure metallic 90-Yttrium coil that can be positioned within the lumen at the target site by the use of a centering device and an afterloading console. Experimental evaluation of this approach showed that a dose of 18 Gy delivered at the inner arterial surface was highly effective in preventing fibrointimal hyperplasia in rabbit carotid and iliac arteries. A pilot clinical evaluation in the coronary arteries of 15 patients using the same dose demonstrated excellent feasibility and no unexpected side-effects. A dose-finding evaluation in the clinical setting is now planned.