Affiliation: Department of Imaging and Interventional Radiology, State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, 510060 Guangdong, P.R. China.
Background and Purpose: Aim of this research is to study the in vivo degradation and biocompatibility in rabbits and the dose distribution of novel iodine-125 seed strands connected using magnesium alloy AZ31. Method: Thirtythree New Zealand rabbits were divided into three Groups (A, B, and C). All rabbits in Groups A and C were implanted with VX2 tumors. For Group A, radioactive iodine-125 seed strands were implanted into the VX2 tumors. For Group B, non-radioactive iodine-125 seed strands were implanted into thigh muscle. Rabbits in Group C were used as controls. Displacement of the seed strands was assessed using X-ray and CT. Blood and urine samples were collected from all groups to measure changes in magnesium ion concentrations. The changing effect of alloy AZ31 tube according to dose distribution of iodine-125 was evaluated using the Monte Carlo method. Results: In Groups A and B, 14 days after implantation, majority of the magnesium alloy tubes were fragmented, and 28 days after implantation, the magnesium alloy tubes were completely degraded. Small differences in dose distribution were observed between bare iodine-125 seeds and iodine-125 seed strands. Conclusions: Our results suggest that these novel iodine-125 seed strands connected using magnesium alloy AZ31 are promising anti-cancer drug for brachytherapy due to the rapid degradation of connective materials and even distribution of seed doses in tumors. Some recent patents are also outlined in this article.