I-123 MIBG SCINTIGRAPHY IN ADULTS - A REPORT OF CLINICAL-EXPERIENCE

Thirty-one adult patients with clinical findings suggestive of pheochr omocytoma were studied with I-123 MIBG. All patients had images obtain ed at 24 and 48 hours. Five patients had abnormal uptake proved to be because of I-123 MIBG avid tumors. The remaining 26 patients had no pr oven tumors and showed physiologic uptake in various organs. The 24-ho ur images were of high quality. In all cases, the 48-hour images contr ibuted no significant additional information. Only in 1 patient did th e 48-hour image add some certainty. Physiologic uptake was seen in the salivary glands, liver, G.I. tract, and urinary bladder in all patien ts (100%). Uptake was also observed in the lung and heart (90%), norma l adrenal glands (32%), thyroid (29%), spleen (23%) uterus (13%), and neck muscles (6%). The authors' experience indicates that I-123 MIBG g ives superior images compared to the previously used I-131 MIBG, that the optimum imaging time for adults is 18-24 hours, and that normal di stribution patterns including uterine and neck muscle uptake should be familiar to physicians interpreting the studies.