Dose-effect relationship in cardiovascular brachytherapy

Abstract

Restenosis after the PTCA (percutaneus transluminal cardiovascular angioplasty) is the most common failure of the invasive treatment in cardiology. The PTCA re-treatment is likely to be followed by repeated restenosis. A well evidenced effective method of restenosis prevention is cardiovascular brachytherapy. A radioactive source, gamma or beta emitter, is introduced into the vessel after the PTCA. The target to be irradiated is the neointima, tissue responsible for the cell proliferation after the PTCA trauma. For dose distribution planning two methods may be used: the so-called “standard dosimetry” and “individual dosimetry”. There exists some controversy concerning dependence of the effectiveness of cardiovascular brachytherapy on the dose delivered and the aim of this paper is to discuss views concerning late effects of brachytherapy. Important role of the analysis of dose-volume histograms (DVH) in cardiovascular brachytherapy is stressed. Description of dose-dependent late adverse side-effects in brachytherapy of cardiovascular restenosis is also given.