Validation and Comparison of [18F]NaF PET/CT Analysis Methods and Derivation of a Semi-population Input Function for Site Specific Measurements of Bone Formation in a Population with Chronic Kidney Disease Mineral and Bone Disorder

Abstract Background Methods for assessing bone metabolism which can replace the gold standard bone biopsy are sorely needed in the clinical setting in patients with chronic kidney disease - mineral and bone disorder (CKD-MBD). The aim of the present study was implementation, validation and comparison of non-invasive dynamic and static whole-body (WB) [ 18 F]NaF PET/CT scan methods to replace invasive bone biopsy, used for quantitative analysis of bone clearance in CKD-MBD patients. Methods Seventeen patients with CKD-MBD underwent a 60-minute dynamic scan followed by a 30-minute static WB scan. Tracer kinetics in four thoracic vertebrae were analyzed using non-linear regression with the Hawkins model and two different Patlak-analysis methods using image-derived arterial input functions obtained from the left myocardial ventricle and the thoracic aorta. For future use in WB PET/CT scans, we validated the use of a semi-population input function. The resulting kinetic parameters (K i , K 1 , k 2 , k 3 , k 4 , V 0 ) were compared between the different methods of analysis using the various derived input functions. Results Dynamic kinetic results from both standard and single-point Patlak analyses correlate well with non-linear regression analysis, but K i results using Patlak analysis are generally lower for all tested input functions compared to regression analysis. Single-point Patlak analysis on WB scans correlates well with standard Patlak analysis on dynamic scans but show 13-21% higher K i -values. Conclusions Our results show good correlation between dynamic and static analysis of skeletal plasma clearance but different K i -values depending on the analysis method and choice of input function used. Thus, WB [ 18 F]NaF PET/CT scans can be applied in future studies, but the results should not be compared uncritically with results obtained using non-linear regression analysis.

Hali tarjima qilinmagan