High-resolution peripheral quantitative computed tomography (HR-pQCT) to detect compartmental bone loss on androgen deprivation therapy (ADT): A feasibility study.

209Background: ADT causes bone loss, yet standard bone density (DXA) measurements do not distinguish cortical vs. trabecular bone loss and are falsely elevated in patients (pts) with sclerotic metastases, potentially underestimating fracture risk. HR-pQCT of the tibia and radius is a validated method to assess compartmental bone density and architecture that may overcome these limitations. Methods: Cross-sectional study of prostate cancer pts who underwent HR-pQCT (Scanco XtremeCT) of the radius and tibia and DXA scans within 6 months of initiating ADT. The relationship between HR-pQCT and relevant clinical variables was assessed using Spearman’s rank correlation method. Results: 22 pts were enrolled. Median baseline characteristics included: age = 64.5 (range 53-90), serum testosterone (T) level = 17 ng/dL (6-978), and interval between ADT start and HR-pQCT = 1.6 months (0-5.7). 5 pts (23%) were osteopenic as assessed by DXA. The correlation between HR-pQCT and clinical variables in shown in the Table. O...