The Effect of Cisplatin on Kidney Uptake of Technetium-99m-MDP in Rats

FROM JAPAN The Effect of Cisplatin on Kidney Uptake of Technetium-99m-MDP in Rats Tachio Sato, Seiro Yoshioka, Yoshinao Abe, Jutaro Takahashi, Kenji Yamada, Hiroshi Fukuda, Yuko Ogata and Masao Tada Departments of Nuclear Medicine, Radiology and Molecular Neurology, Institute of Development, Aging and Cancer, Tohoku University and the Department of Radiology, Sendai Kosei Hospital, Sendai, Japan Translation by Iku Burns, Cardiovascular Associates of the Peninsula, San Francisco, California Objective: The following experiments were performed to study the effect of cisplatin on the uptake of "'Tc-MDP in kidneys. There is renal accumulation of mTc-MDP bone imaging agents in patients treated with cisplatin. Methods: Donryu rats weighing 150-160 g were administered 0.8 mg/kg of cisplatin intravenously for 7 days. On the day following the cisplatin injections and on the 37th day, we obtained mTc-MDP clearance from the blood and it showed two components: a fast and a slow component. Results: On both the first and 37th days, the fast component of the cisplatin-treated group was identical to the control rats. On the contrary, the slow component of the cisplatintreated group and control rats was 393.6 ::!:: 116.4 min and 85.2 ::!:: 19.9 min, (p < 0.001), respectively. On the 37th day, the slow components in both groups were not significantly different. Technetium-99m-MDP bone scanning was performed on the first, 15th and 37th days following cisplatin administration. The scintigram on the first day showed high uptake mTc-MDP in kidneys, bones and liver. On the 15th day, relatively high uptake in kidneys was observed. However, on the 37th day, mTc-MDP uptake of the kidneys returned to normal. The binding rate of "'Tc-MDP and mTc-MDP with cisplatin were 99.4 ::!:: 0.6% and 79.0 ::!:: 4.6%, respectively. Conclusion: This study suggested that high renal uptake of mTc-MDP following administration of cisplatin was mainly due to delayed excretion of the radiopharmaceutical by binding with cisplatin.