Assessment of regional and total skeletal metabolism using 18F-NaF PET/CT in patients with chronic kidney disease

Objective

The study aims to assess regional and total bone metabolic activity in patients with chronic kidney disease using Na[¹⁸F]F PET and correlation between semi-quantitative indices and blood parameters.

Methods

Seventy-two subjects (mean age 61.8 ± 13.8 years) were included. Of these 24/72 patients had end-stage renal disease (ESRD) (GFR < 15 mL/min/1.73 m²), 38/72 had chronic kidney disease (CKD) (GFR between 60 and 15 mL/min/1.73 m²), and 10/72 were controls with normal renal function. All subjects underwent Na[¹⁸F]F PET-CT with a dose activity of 0.06 mCi/Kg. Regional and total skeletal metabolism were assessed with mean SUVs in a skeletal volume of interest (VOI), bone to soft tissue index (B/S), global SUV mean (GSUV mean) of the whole bone, and uptake in the femoral neck.

Results

Statistically significant differences were observed in a number of ¹⁸F-NaF metrics like femoral neck metabolism in CKD and ERSD groups in comparison to control in right (P = 0.003) and left femur (P = 0.006), bone to soft tissue index in the femur (P = 0.016) and GSUV₅ (P = 0.006). There is also a significant difference in SUV mean in lumbar vertebrae (L1–L4) among CKD, ESRD, and controls. There was a moderate correlation between ¹⁸F-NaF PET scan uptake and blood parameters such as ALP and PTH. Na[¹⁸F]F uptake parameters were significantly different in low versus high bone turnover state.

Conclusions

The assessment of total skeleton and regional metabolism and bone turnover in CKD patients is feasible with Na[¹⁸F]F PET. Na[¹⁸F]F can help to detect early changes in bone metabolism and assess the progression of bone disease in this complex condition. Quantification with Na[¹⁸F]F PET might provide better assessment of the bone turnover. The difference in Na[¹⁸F]F uptake in CKD compared to controls is likely related to a change in bone turnover which, however, requires further validation.