Radiolabeling of Cisplatin and Its Biodistribution in an Experimental Model of Lung Carcinogenesis

Abstract

This study optimized the radiolabeling of cisplatin with technetium-99m (99mTc) and evaluated its biodistribution in an experimental model of lung carcinogenesis. The percentage labeling of cisplatin with 99mTc was assessed using an ascending chromatographic technique. For biodistribution studies, male rats were divided into 2 groups. The control group received normal saline intratracheally, whereas the treatment group received intratracheal administration of carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) at a dose of 20 mg/kg body weight. The resulting radiopharmaceutical (99mTc-cisplatin) showed 98% labeling efficiency and was found to be stable for up to 6 hours both in both serum and saline under normal conditions. The blood clearance of the 99mTc-cisplatin followed a biphasic release pattern whereby a fast-release phase was observed at 35 seconds and a slow-release phase was observed after 30 minutes of drug administration. The biodistribution studies of control and treated animals revealed high uptake of 99mTc-cisplatin by the liver and slow excretion via the kidneys. However, a time-dependent increase in the lung-to-muscle specific uptake ratio was observed in DMBA-treated rats. The study concluded that 99mTc-cisplatin possesses selectivity toward cancerous lung tissue and can be explored further for its diagnostic potential in the detection of lung cancer and the evaluation of treatment response.