Comparative analysis of 11 different radioisotopes for palliative treatment of bone metastases by computational methods

Abstract

Purpose: Throughout the years, the palliative treatment of bone metastases using bone seeking radiotracers has been part of the therapeutic resources used in oncology, but the choice of which bone seeking agent to use is not consensual across sites and limited data are available comparing the characteristics of each radioisotope. Computational simulation is a simple and practical method to study and to compare a variety of radioisotopes for different medical applications, including the palliative treatment of bone metastases. This study aims to evaluate and compare 11 different radioisotopes currently in use or under research for the palliative treatment of bone metastases using computational methods. Methods: Computational models were used to estimate the percentage of deoxyribonucleic acid (DNA) damage (fast Monte Carlo damage algorithm), the probability of correct DNA repair (Monte Carlo excision repair algorithm), and the radiation-induced cellular effects (virtual cell radiobiology algorithm) post-irradiation with selected particles emitted by phosphorus-32 (P-32), strontium-89 (Sr-89), yttrium-90 (Y-90), tin-117 (Sn-117m), samarium-153 (Sm-153), holmium-166 (Ho-166), thulium-170 (Tm-170), lutetium-177 (Lu-177), rhenium-186 (Re-186), rhenium-188 (Re-188), and radium-223 (Ra-223). Results: Ra-223 alpha particles, Lu-177 beta minus particles, and Tm-170 beta minus particles induced the highest cell death of all investigated particles and radioisotopes. The cell survival fraction measured post-irradiation with beta minus particles emitted by Sr-89 and Sm-153, two of the most frequently used radionuclides in the palliative treatment of bone metastases in clinical routine practice, was higher than Lu-177 beta minus particles and Ra-223 alpha particles. Conclusions: Ra-223 and Lu-177 hold the highest potential for palliative treatment of bone metastases of all radioisotopes compared in this study. Data reported here may prompt future in vitro and in vivo experiments comparing different radionuclides for palliative treatment of bone metastases, raise the need for the careful rethinking of the current widespread clinical use of Sr-89 and Sm-153, and perhaps strengthen the use of Ra-223 and Lu-177 in the palliative treatment of bone metastases. (C) 2014 American Association of Physicists in Medicine.