[Pharmacokinetics of 99mTc-technephore in man]

Assessment of the pharmacokinetics of 99mTc-technephore in the human body was based on an analysis of the results of its study in 43 out of 87 patients with neoplasms of non-osteogenic origin (breast cancer, lung cancer, reticulum cell sarcoma, etc.). Radiometry by means of a counter of the whole human body radiation was performed shortly after the drug administration with one-hour intervals for 4-5 hours. Methods of blood radiometry and osteoscintigraphy were employed. The study showed that the redistribution of the drug occurred in the first minutes after its injection, chiefly between the 2 volumes: the skeleton and the urinary system. The value of its activity in the bladder by the 3rd hour was 59% of the administered amount. Clearance of the blood was rapid and its radioactivity by the 3rd hour was no more than 6% of the administered amount. The amount of the drug by the same time was within 31-32%. A high gradient of differential accumulation of the drug in the osseous tissue and the adjoining tissues (the skeleton/background-312%) made it possible to get high-quality scintigrams. Investigations of the patients with the help of gamma-chambers and scanners were initiated 2.5-3 hours after the drug injection. The sensitivity and specificity of 99mTc-technephore were similar to those of other phosphatic and phosphonate radiopharmaceuticals: 96 and 12%. A conclusion was made that the drug could be used in clinical practice as an osteotropic agent.