Endovascular beta-irradiation after percutaneous transluminal coronary balloon angioplasty

Intraluminal beta-irradiation has been shown to markedly decrease fibrointimal proliferation after arterial injury in experimental models. With the aim of reducing the incidence of restenosis after percutaneous transluminal coronary angioplasty (PTCA), we undertook a pilot clinical evaluation to assess both the technical feasibility and the clinical safety of this treatment after balloon coronary angioplasty.

Between June 21 and November 15, 1995, 15 patients (6 women and 9 men, aged 72 +/- 5 years) underwent intracoronary beta-irradiation immediately after a conventional PTCA procedure. Both the PTCA and irradiation procedure were done in a conventional catheterization laboratory, using an endoluminally centered pure metallic 90Y source, a newly developed technique of intracoronary beta-irradiation. This was done after documenting the ability of the system to generate reproducible dose delivery to the arterial wall.

Both the PTCA and the irradiation procedure were technically feasible in all attempted cases, and a dose of 18 Gy was delivered with a local exposure time of 391 +/- 206 s (range 153-768). In four patients, the intervention was completed by intraarterial stent implantation because of dissection induced by the initial PTCA. No in-hospital complications occurred, and serial creatine kinase measurements remained within the normal range in all cases.

Our early experience thus suggests that reliable and reproducible dose delivery can be achieved, and that coronary endoluminally centered beta-brachytherapy is both feasible and safe on a short-term basis in the clinical setting. Whether this novel mode of therapy will favorably influence post-PTCA restenosis in patients, as it does in experimental models, must await long-term angiographic follow-up of the present series as well as further clinical study.