Dosimetric evaluation of several candidate radionuclides used in radionuclide therapy of bone metastases in an upper leg model

Abstract

IntroductionOne of the most effective and well-known approaches to reduce the pain of bone metastases is targeted radionuclide therapy. Here several radionuclides which are candidates of treatment and pain reduction of bone metastases were dosimetrically evaluated on an upper leg model using MCNPX simulation code. MethodsRadiation dose distribution of nine different radionuclides, including 89Sr, 149Pm, 153Sm, 166Ho, 169Er, 177Lu, 186Re, 188Re, and 223Ra was determined in upper leg model using MCNPX Monte Carlo code. RADAR Decay nuclear data on gamma and beta radiation energy and the probability of emission, as well as ICRU and ICRP data for tissue constituents, were used to calculate the dose. ResultsThe absorbed dose profiles according to the radius of the phantom for the different beta and gamma radiations of the mentioned radionuclides indicated a high dose variation in bone tissue compared to normal tissues. The results showed that 188Re, 89Sr, 166Ho, and 149Pm radionuclides have higher radiation dose to the upper leg bone and soft tissue compared to other radionuclides due to the radiation of beta particles. 223Ra had the highest radiation dose to bone tissue but other radionuclides had the higher radiation dose to soft tissue. ConclusionThe data reported here may be useful to select and elucidate the proper radionuclide based on its toxicity profile in healthy tissues. Due to the increasing clinical interest in the use of radionuclides for the palliative treatment of bone metastasis pain, we hope to see reports of clinical applications of new radionuclides soon.