Assessment of diffuse bone marrow involvement on 18F-fluoro-D-glucose PET/computed tomography

Purpose: This study aims to investigate the role of bone marrow (BM) FDG uptake distribution by 18 F-FDG PET/CT in assessing pathological status of BM with diffusely increased FDG uptake. Methods: We retrospectively analyzed one hundred and thirty-four PET/CT scans with diffusely increased FDG uptake in BM, which involved forty-nine patients with malignant diseases of BM and eighty-five patients with benign disorders of BM. The maximum standardized uptake values (SUVmax) of axial skeletons (spine, ribs, sternum, pelvis), appendicular skeletons (proximal humerus, proximal femur, clavicle, scapula), and the range of humerus FDG uptake were measured, and the clinical and laboratory data were collected. Multivariate logistic regression analysis and receiver operating characteristic (ROC) curve were used to evaluate the risk factors for BM malignancies and discriminative ability of above indicators for pathology status of BM with diffusely increased FDG uptake. Results: In patients with diffusely increased FDG uptake in BM, both the glucose metabolism in axial and appendicular skeletons were higher in BM malignancies than benign disorders. The multivariate logistic regression analysis (stepwise) revealed age (odds ratio [OR] 1.073; 95%CI, 1.031-1.117; P =0.001), femurs SUVmax (OR 2.058; 95%CI, 1.317-3.218; P =0.002), neutrophil count (OR 0.805; 95%CI, 0.718-0.902; P <0.001) and range of humerus FDG uptake (OR 11.335; 95%CI, 2.831-45.377; P =0.001) were associated with BM malignancies. Combined diagnosis had the highest ROC value (AUC 0.918; 95%CI, 0.864-0.973; P <0.001) with a sensitive of 89.8% and specificity of 85.9%. Conclusion: Metabolic information of appendicular skeletons on FDG PET/CT was significant for assessing diffuse involvement in BM. Age combined femurs SUVmax, neutrophil count and range of humerus FDG uptake was reliable in differentiating BM malignancies from benign disorders.