Bone scintigraphy in Paget's disease treated with combined calcitonin and diphosphonate (EHDP)

Bone scintigraphic results for 28 patients with Paget's disease treated with a combination of EHDP and calcitonin are reported. The uptake of the bone scintigraphic agent decreased considerably during the first year of treatment. There was good correlation between scintigraphic and biochemical changes, but most of the 22 patients who attained normal biochemical values still had one or more active lesions scintigraphically. Remission of disease does not therefore mean normalization of the bone scintigram. All affected bones showed a distinct drop in activity, but lesions with a higher initial activity remained more active than lesions with a lower initial activity. One third of the affected bones normalized completely, although radiographic anomalies persisted. There were slight differences in scintigraphic activity depending on the anatomical site. The success of treatment, however, could not be predicted from the pretreatment scintigram. A recurrence of disease was often visible on the scintigram, in certain cases 6 months prior to the biochemical decline. This could be of importance in the therapeutic management of the recurrence.