The effects of inadvertent administration of antineoplastic agents prior to Ga-67 injection: concise communication.

Alteration of the gallium-67 (Ga-67) distribution after administration of chemotherapeutic agents has been demonstrated in experiments on both normal and tumor-bearing animals. We have encountered eight patients who had Ga-67 scintigrams in which the findings were similar to those in the animals experiments: markedly increased uptake in bone, with suppressed uptake in liver, muscle, and tumor. Five of the patients had hematologic neoplasms, and three had solid tumors, and each had received one or more chemotherapeutic agents during the 24 hr preceding Ga-67 administration. In three patients while not on antineoplastic medication subsequent Ga-67 images showed a return to the usual Ga-67 distribution pattern. The altered Ga-67 distribution may result from inhibition of protein synthesis or of a serum-binding agent for Ga-67, or from competitive blockage of specific Ga-67 organ receptors by the antineoplastic agents.