Effect of desferoxamine on tissue and tumor retention of gallium-67: concise communication.

Desferoxamine (DEF) was administered intramuscularly (0.25 mg/g body weight) to mice harboring a Cloudman's melanoma S-91 3 hr before, simultaneously with, and 3 hr after i.v. injection of Ga-67 citrate (approximately 1 microCi/g body weight). Relative Ga-67 retention was compared with that in non-DEF controls at 24 hr. The chemical nature of Ga-67 excreted in urine following DEF was also studied in healthy mice. Desferoxamine administered 3 hr before Ga-67 had little effect on radiogallium localization; administration coincident with or 3 hr after radiogallium resulted in decreased retention at 24 hr. The effect was most profound when Ga-67 and DEF were administered simultaneously. In DEF-injected animals Ga-67 was excreted in the urine as a Ga-67-DEF complex. When DEF was administered 3 hr after Ga-67, there was a trend to greater tumor-to-blood activity ratios (.2 > p > .1).