Effect of Doxorubicin on the Uptake of 99mTc-DTPA in Rat kidneys

Abstract

Diethylenetriaminepenta-acetic acid (DTPA) is a chelating agent used as a radiopharmaceutical compound, 99mTc-DTPA, for renography. Doxorubicin (DOX) on the other hand is an anthracycline antibiotic frequently used in treatment of various solid malignancies. Both 99mTc-DTPA and DOX may be used in close succession in patients undergoing DOX based chemotherapy to evaluate renal function. Here, effects of DOX on99mTc-DTPA uptake in normal Sprague Dawley rat kidneys have been explored. The study was divided in two arms; a control group (n=10) where 99mTc-DTPA alone and the experimental group (n=30) where DOX was injected prior to 99mTc-DTPA administration. The experimental group was further divided into six subgroups (n=5 each) based on the time intervals (4, 8, 18, 36, 72, 96 hours) between DOX and 99mTc-DTPA administration. In each group, the subjects were sacrificed 2 hours post 99mTc-DTPA injection, the organs isolated and counted for radioactivity. Results revealed that the percentage total retained dose (%TRD) significantly decreased in urinary tract while increased in liver and biliary tree in the experimental group. These results put the accuracy of renal scintigraphy in question in patients receiving DOX based chemotherapy. However, human studies are proposed for validity of results with regards to clinical practice.