Orbital accumulation of gallium-67 citrate

In order to determine the normal range of Gallium-67 citrate (Ga-67) accumulation in the orbital regions, and to possibly identify groups tending to have increased Ga-67 concentration in the eyes, 75 studies were performed prospectively over a two-month period. No difference in the ocular count/background ratio was found on the basis of sex, or on the basis of symptomatic ocular involvement in a systemic disease process. A significant difference in this ratio was found between age groups separated by 20 years or more, with younger patients tending to have higher ocular counts. This decrease in the ratio with age possibly reflects the physiologic senile involution of the lacrimal apparatus with time. The wide range of normal ocular Ga-67 accumulation should be kept in mind, and demonstrable Ga-67 concentration in the orbital regions need not be automatically ascribed to a pathologic process.