A baseline Ga-67 study was requested for a 15-year-old girl, who was recently diagnosed with T-cell non-Hodgkin's lymphoma. Pending the Ga-67 study, she was started on chemotherapy with vincristine (1.5 mg/m2), adriamycin (50 mg/m2), cyclophosphamide (1000 mg/m2), end prednisone (60 mg intravenously every 6 hours). On day 4 of chemotherapy, 5.0 mCl of Ga-67 was administered intravenously. Forty-eight and 72 hour images were obtained using a large-held-of-view gamma camera end high-energy collimator, with separate photo peak settings at 93, 185, and 296 KeV. The whole-body images demonstrated normal Ga-67 uptake in the bone marrow end physiologic Ga-67 uptake in both breasts. However, no Ga-67 uptake was identified in the liver or tumor mass. The suppressed Ga-67 uptake most probably resulted from the chemotherapy induced hyperferremia and possible competitive antagonism between Ga-67 and iron for organ receptors.
