Ultrasound imaging and therapeutic efficacy of 188Re-liposome in a C26 colon tumor-bearing mouse

2610 Objectives Liposomes are good drug delivery system which allow the encapsulation of drugs into vesicles for their delivery. The objective of this study is to investigate the therapeutic efficacy of a new radio-therapeutics of 188Re-labeled pegylated liposome in a C26 murine colon carcinoma solid tumor model. Methods The anti-tumor effect of 188Re -liposome was assessed by tumor growth inhibition, survival ratio and ultrasound imaging. Apoptotic marker was also evaluated by TUNEL (terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling) method in tumor samples obtained at 8 h after injection of 188Re-liposome. Noninvasive monitoring of anti-angiogenesis and tumor volume of C26 murine colon tumors treated with 188Re-liposome was performed by serial 3-D power Doppler ultrasound imaging. Results Tumor growth inhibition of mice treated with 188Re-liposome was obviously precisely controlled (Mean tumor size was 245.8 ± 150.23 mm3; Mean growth inhibition rate (MGI) was 0.135) and have longer median survival time (62 d) than those treated with anti-cancer drug 5-FU and untreated control mice (39 d and 30 d, respectively). The ultrasound imaging showed a decrease in the tumor volume and number of blood vessels. There were significantly more apoptotic nuclei (TUNEL-positive) in the treated mice 8 h after 188Re-liposome treatment as compared with control mice. Conclusions These results were pointed to the potential benefit of the radio-therapeutics 188Re-liposome for adjuvant cancer treatment on oncology applications