Measurement of 24-hr whole-body retention of Tc-99mMDP with a thyroid uptake probe: quantitative assessment of metabolic and metastatic bone diseases

A new method for measurement of 24-hr whole body retention (WBR) of Tc-99mMDP, using a thyroid uptake probe was established and its clinical significance was evaluated in 102 patients with various bone disorders, including metabolic and metastatic bone diseases, aged above 20 years old. Reproducibility of 24-hr WBR in 10 patients was very good (r=0.996). The 24-hr WBR of Tc-99mMDP in the normal subjects was 30.4 +- 4.6%. The WBR values of chronic renal failure, metastatic bone disease and hyperthyroidism groups were 98.4 +- 3.0, 44.0 +- 8.0, 40,6 +- 6.3% respectively, which were significantly higher (p < 0.001). However the WBR of steroid-induced osteoporotic group was significantly lower (17.3 +- 5.4%) as compared with the normal group (p < 0.001). Based on these results the method is simple, reproducible and accurate to measure 24-hr WBR of Tc-99mMDP. Quantification of WBR is of great clinical value to diagnose metabolic bone disease and to follow-up metabolic and metastatic bone disease after treatment