Therapy study of combined 188Re-liposome with 5-FU in CT26-luc lung-metastatic mice

1463 Objectives The aim of this study was to investigate the therapeutic efficacy of intravenously administrated 5-FU, 188Re-liposome and combination of 188Re-liposome with 5-FU in the CT26-luc lung-metastatic model. Methods These studies were performed on mice at 17 d after intravenous inoculation with CT26-luc cells. The comparative efficacy of 5-FU, 188Re-liposome and combination of 188Re-liposome with 5-FU were performed by a single-dose treatment in lung-metastatic tumor-bearing mice. Mice were checked for survival every day until death. The body weight was measured twice a week. Results In efficacy study, the median survival time for the mice, which received normal saline was 32.25 d. The median survival times for the mice treated with 5-FU (36 mg/kg), 188Re-liposome (22.2 MBq) and combination of 188Re-liposome (22.2 MBq) with 5-FU (36 mg/kg) were 34.25 d (P = 0.969), 38.5 d (P = 0.069) and 41.5 d (P = 0.011), respectively. The increase in life span of 5-FU (36 mg/kg), 188Re-liposome (22.2 MBq) and combination of 188Re-liposome (22.2 MBq) with 5-FU (36 mg/kg) were 6.2%, 19.4% and 28.7%, respectively. Conclusions The therapeutic studies of combined 188Re-liposome with 5-FU demonstrated better survival time and therapeutic efficacy for mice compared with 5-FU or 188Re-liposome in CT26-luc lung-metastatic mice model. These results suggested that intravenous administration of combined 188Re-liposome with 5-FU could provide a benefit and promising strategy for delivery of passive nanotargeted radiotherapeutics in oncology applications.