Gallium scanning in Paget's disease of bone: effect of calcitonin.

Calcitonin has been used in the treatment of Paget's disease of bone, and serum alkaline phosphatase level and 24 hr urinary hydroxyproline excretion have been used to follow therapeutic response. The radionuclide bone scan has been used as a visual indicator; however, there is some uncertainty as to its value in following changes in disease activity. Four patients with both serial technetium phosphate bone scans and serial gallium studies were studied. In each case the beneficial effect of calcitonin was demonstrated more accurately with gallium than with technetium diphosphonate. Since biochemical changes in Paget's disease are believed to be mediated at the cellular level and gallium uptake depends on cellular activity, it is proposed that gallium uptake is a more appropriate measure of the activity of Paget's disease than a noncellular marker such as a technetium-containing bone scan agent.