99mTc(V)-DMSA scintigraphy in monitoring the response of bone disease to vitamin D3 therapy in renal osteodystrophy.

Renal osteodystrophy (ROD) is a common and serious complication for uremic patients and patients are treated with 1,25-dihydroxyvitamin D3. The bone scanning agent 99mTc-phosphate has also been used to evaluate in ROD but it is not clear that bone scintigraphy has a role in the follow-up of treatment. In this study 99mTc(V)-DMSA scintigraphy was performed in eleven patients [age 40.7 +/- 17.3 (mean +/- SD) yr] with ROD before and after vitamin D3 therapy. Images were obtained after hemodialysis performed following tracer injection to maintain normal blood levels of the radiopharmaceutical and to reduce soft tissue activity. Lumbar vertebra-to-soft tissue uptake ratios (LUR) were quantified with the planar 99mTc(V)-DMSA images. Alkaline phosphatase and parathyroid hormone levels after treatment had significantly decreased compared with pre-therapy. In all patients there was visually decreased uptake in bone structures after treatment. After treatment the mean LUR ratio was significantly lower than those of before treatment (3.59 +/- 2.63 vs. 1.65 +/- 0.62; p = 0.01). LUR values were correlated with pre-therapy alkaline phosphatase and parathyroid hormone. These findings indicate that 99mTc(V)-DMSA scintigraphy is sensitive in evaluating the response of ROD to vitamin D3 therapy.