Comparison of ⁶⁰Co and ¹⁹²Ir sources in HDR brachytherapy

Abstract

This paper compares the isotopes ⁶⁰Co and ¹⁹²Ir as radiation sources for high-dose-rate (HDR) afterloading brachytherapy. The smaller size of ¹⁹²Ir sources made it the preferred radionuclide for temporary brachytherapy treatments. Recently also ⁶⁰Co sources have been made available with identical geometrical dimensions. This paper compares the characteristics of both nuclides in different fields of brachytherapy based on scientific literature. In an additional part of this paper reports from medical physicists of several radiation therapy institutes are discussed. The purpose of this work is to investigate the advantages or disadvantages of both radionuclides for HDR brachytherapy due to their physical differences. The motivation is to provide useful information to support decision-making procedures in the selection of equipment for brachytherapy treatment rooms. The results of this work show that no advantages or disadvantages exist for ⁶⁰Co sources compared to ¹⁹²Ir sources with regard to clinical aspects. Nevertheless, there are potential logistical advantages of ⁶⁰Co sources due to its longer half-life (5.3 years vs. 74 days), making it an interesting alternative especially in developing countries.