The effect of mitomycin-C on the biodistribution of 99Tcm-MDP in Balb/c mice

SUMMARYDrug therapy can alter the biodistribuition of radiopharmaceuticals. We studied the effect of mitomycin-C, a drug used in oncology, on the biodistribution in mice of Tc-methylene diphosphonic acid (Tc-MDP). Three doses of mitomycin-C were administered. After the last dose, Tc-MDP was injected and the animals were killed. The organs were isolated, their weight determined and the percent per gram injected dose (%ID/g) calculated. The %ID/g had increased in the pancreas, ovary, stomach, uterus, kidneys, spleen, thymus, heart, liver and lungs, but did not change significantly in thyroid, bone or brain. As a change in Tc-MDP uptake by bone is not observed, a modification to bone scintigraphy is not required. As mitomycin-C treatment altered Tc-MDP uptake in some organs, any hot spots should be evaluated carefully to avoid a misdiagnosis.