Objectives  

To evaluate the bone involvement of the mandible, cranium, radius, and femur in secondary hyperparathyroidism (SHPT) using ^99mTc-MDP uptake correlated with the serum intact parathyroid hormone (PTHi).

Methods  

In a prospective study of 54 patients with SHPT due to chronic renal disease and 15 normal individuals (control group), all patients had elevated serum PTHi and positive ^99mTc-MDP bone scintigraphy. Bone uptake was measured in regions of interest (ROIs) in the mandible, posterior cranium, distal radius, and proximal femur. In addition, soft tissue uptake was measured in one ROI in the soft tissues of the medial thigh (BG). The ROI-BG ratio was used as an index of the normalized bone uptake.

Results  

The uptake differences in the SHPT and control groups were statistically significant for the mandible (P = 0.001) and cranium (P = 0.002). When the SHPT group was subclassified according to serum PTHi levels, the bone uptake increased with the serum PTHi level. All mandibles of the patients with SHPT were abnormal, and 33% had focal lesions.

Conclusions  

The bone uptake in the SHPT group was abnormal in all areas evaluated, and a high uptake of ^99mTc-MDP was correlated with an increased serum PTHi.