Desferoxamine mesylate (Desferal): a contrast-enhancing agent for gallium-37 imaging

Desferal (desferoxamine mesylate) was investigated as a contrast-enhancing agent for tumor and abscess imaging with 67Ga-citrate. Tumor studies were performed in mice with Cloudman S-91 melanoma. Abscess studies were performed with a subcutaneous abscess model in rabbits. When Desferal is administered 16 to 18 hours after injection of 67Ga, rapid blood clearance of 67 Ga occurs with only slight (tumor) or no (abscess) loss of activity from the lesion. Retention in other organs is variable. Tumor-to-blood ratios are improved eightfold in tumor and fourfold in abscess in studies performed with single Desferal injections of 150 mg/kg. Blood and total body clearance studies in rabbits reveal that maximum Desferal effect is achieved in the 17 to 50 mg/kg dose range and that only minimal improvement occurs at higher doses.