Bone turnover prediction in patients with chronic kidney disease (CKD) undergoing hemodialysis using shortened...

This study investigated whether K_i-Patlak derived from a shortened scan time for dynamic ¹⁸F-NaF PET/CT in chronic kidney disease (CKD) patients undergoing hemodialysis can provide predictive accuracy comparable to that obtained from a longer scan. Twenty-seven patients on chronic hemodialysis, involving a total of 42 scans between December 2021 and August 2023 were recruited. Dynamic ¹⁸F-NaF PET/CT scans, lasting 60-90 min, were immediately acquired post-injection, covering the mid-twelfth thoracic vertebra to the pelvis region. K_i-Patlak analysis was performed on bone time-activity curves at 15, 30, 45, 60, and 90 min in the lumbar spine (L1-L4) and both anterior iliac crests. Spearman's rank correlation (r_s) and interclass correlation coefficient were used to assess the correlation and agreement of K_i-Patlak between shortened and standard scan times. Bone-specific alkaline phosphatase (BsAP) and tartrate-resistant acid phosphatase isoform 5b (TRAP5b) were tested for their correlation with individual K_i-Patlak. Strong correlations and good agreement were observed between K_i-Patlak values from shortened 30-min scans and longer 60-90-min scans in both lumbar spine (r_s = 0.858, p < 0.001) and anterior iliac crest regions (r_s = 0.850, p < 0.001). The correlation between BsAP and K_i-Patlak in the anterior iliac crests was weak and statistically insignificant. This finding suggests that a proposed shortened dynamic ¹⁸F-NaF PET/CT scan is effective in assessing bone metabolic flux in CKD patients undergoing hemodialysis, offering a non-invasive alternative approach for bone turnover prediction.