A comparison of radiography and radioisotope scanning in the detection of Paget's disease and in the assessment of response to human calcitonin.

In eight patients with symptomatic Paget's disease, radiographs and radioisotope bone scans have been compared before treatment by high dose synthetic human calcitonin (CIBA 47175-Ba) and three months and 12 months later. In six patients quantitative radioisotope scans allowed calculation of relative radioactivity in normal bone, Paget's disease and bone adjacent to osteoarthritic joints. Comparison of radiographs and scans showed 69 sites diagnosed as Paget's disease on both examinations; nine sites showed radiographic changes of Paget's disease but had negative radioisotope scans and two sites were abnormal on the scan but radiologically normal. One of these two reverted towards normal during treatment with calcitonin. Comparison of analogue scans done at three months and 12 months with initial scans showed diminished uptake in Paget's disease compared with normal bone, and quantitation showed this was due to decreased absolute uptake in Paget's disease and a slight increase in normal bone. Osteoarthritic bone showed no significant response to calcitonin.