Iodine - 131 - Iodomethyluridine을 이용한 종양세포증식의 영상화에 관한 실험적 연구 = Imaging of Tumor Proliferation Using Iodine - 131 - Iodomethyluridine

다국어 초록 (Multilingual Abstract)

Purpose: Noninvasive imaging of tumor cell proliferation could be helpful in the evaluation of tumor growth potential and could provide an early assessment of treatment response. Radiolabeled thymidine, uridine and adenosine have been used to evaluate tumor cell proliferation. These nucleoside analogs are incorporated into DNA during proliferation. Iodine-131-Iodomethyluridine, an analog of Iodine-131-Iododeoxyuridine, is also involved in DNA/RNA synthesis. The purpose of this study was to develop Iodine-131-Iodomethyluridine and image tumor proliferation using Iodine -131-Iodomethy-luridine. Materials and Methods: Radiosynthesis of Iodine-131-5-Iodo-2'-O- methyluridine(Iodine-131-Iodomethyluridine) was prepared from 10 mg of 2'-O-methyluridine (Sigma chemical Co., St. Louis, Missouri)-and 2.1 mCi(SP. 10Ci/mg) of Iodine-131-labeled sodium iodide in 100 μl of water using iodogen reaction. Female Fischer 344 rats were inoculated in the thigh area with breast tumor cells (13765 NF, 105 cells/rat S.C.). After 14 days, the Iodine-131- Iodomethyluridine 10μCi was injected to three groups of rats(3/group). The percent of injected dose per gram of tissue weight was detennined at 0.5-hours, 2-hours, 4-hours, and 24-hours respectively. Tumor bearing rats after receiving Iodine-131-Iodomethyluridine(50μCi/rat, IV) were euthanized at 2 hours after injection. Autoradiography was done using freeze-dried 50 μ m coronal section. After injection of Iodine-131-Iodomethyluridine (100μCi/rat, IV) in three breast tumor-bearing rats, planar scintigraphy was taken at 45 minutes, 90 minutes and 24 hours. Results: Iodine-131-Iodomethyluridine was conveniently synthesized using iodogen reaction. The biodistribution showed fast blood clearance and the tumor-to-tissue uptake ratios showed that optimal imaging time was at 2 hours postinjection. Autoradiogram and planar scintigram indicated that tumor could be well visualized. Conclusion: The findings suggest that Iodine-131- Iodomethyluridine, a new radio-iodinated nucleoside, has potential use for evaluation of active regions of tumor growth.