Deposition of 90VPO4 and 144CePO4 radioisotopes on polymer surfaces for radiation delivery devices

Abstract

Intravascular irradiation with β emitters inhibits restenosis in arteries after balloon angioplasty or stent implantation. Yttrium-90 (90Y, T1/2=64 h) and cerium-144 (144Ce, T1/2=286 d) emit beta particles (Emax=2.28-3.50 MeV) having an ideal energy range for brachytherapy delivery system. In this article, a previously reported method for depositing 32p on poly(ethylene terephtalate) (PET) surfaces is generalized and modifications that allow deposition of other β-emitting radioisotopes, such as 9OY and 144Ce, are demonstrated. PET films were first coated with chitosan hydrogel and then adsorbed different amounts of phosphoric acid (PA) in aqueous solutions. Yttrium was deposited onto the surface as YPO4 after the films were immersed in YCI3 solutions. 1μCi 90YCI3 (2x 10-9 g) was used in each sample as a tracer for measuring the deposition efficiency, which is defined as the percentage of YCI3 deposited on the surface compared to the amount of YCI3 in solutions before the deposition. In order to improve the safety of brachytherapy treatments, polyurethanes were used to seal the deposited radioisotopes on the surface to minimize the leakage of the isotopes into the patients. The generality of this method presented here for a wide variety of particular radioisotopic components allows design of a broad range of versatile radioisotope sources. © 2002 John Wiley & Sons, Inc.