Objective: To investigate the preparation of 188Re-diethylenetriaminepentaacetic acid-2-deoxyglucose (188Re-DTPA-DG) and its imaging quality and therapeutic effect. Methods: Labeling of DTPA-DG with 188Re was performed in the presence of stannous ion and sodium D-gluconate at a pH of 5.5 with 3 hours of incubation at 37°C. The radiolabeling yields of 188Re-DTPA-DG were determined by paper chromatography with a solution of acetone and saline (0.9% NaCl) as a developing agent. The imaging quality of 188Re-DTPA-DG was determined by injecting 0.1 mL of a preparation having a radioactivity of 92.5GBq/L into the tail vein of nude mice bearing MCF-7 mammary tumors and imaging the tumors at 2, 4, 8, 12, and 24 hours after injection of the radiolabeled agent. Tumor volume was recorded every 2 or 3 days for 21 days. Results: The radiochemical purity of the 188Re-DTPA-DG complex was 95.0%. In the imaging study, the tumor-to-nontumor-tissue ratios (T/NT) of radioactivity at 12 and 24 hours after intravenous injection of the radiolabeled agent were 5.9 and 7.8, respectively. The tumor volume in the 188Re-DTPA-DG-treated group of mice increased more slowly than that in the control group, and the two groups differed greatly in this measure at 21 days, with tumor volumes of 823.6 ± 50.58 mm3 and 1162.7 ± 73.08 mm3 in the 188Re-DTPA-DG treated and control groups, respectively (p < 0.01). Conclusions: 188Re-DTPA-DG showed excellent tumor targeting and tumor-growth-suppressing effects, and holds promise as an internal agent for tumor radiotherapy.
