Desferal (DFO) induced Ga-67 washout from normal tissue, tumor and abscess in experimental animals

In the experimental animal, desferal (DFO) given intravenously washes out Ga-67 from all tissues. This effect is not uniform: blood activity is reduced very markedly, while liver activity is less affected. Maximal effect of DFO occurs if given close to the Ga-67 injection. When the time interval between the two is increased, the absolute amount of Ga-67 excreted in the urine in excess of the spontaneous excretion is reduced. Administration of DFO does not effect Ga-67 gastrointestinal excretion. In three animal tumor models (EMT-6 sarcoma in Balb/c mice, spontaneous adenocarcinoma in mice, and spontaneous adenocarcinoma in the rabbit) and in sterile abscess-bearing rats, the administration of DFO 24 hrs after Ga-67-citrate improves significantly the target-to-nontarget ratio. Animals given 50 mg/kg DFO I.V. after Ga-67 citrate showed a significant reduction in the whole-body activity as seen in a one-week follow up