The role of 18F-fluoride PET-CT in the detection of bone metastases in patients with breast, lung and prostate carcinoma: a comparison with FDG PET/CT and 99mTc-MDP bone scan

We aimed to compare the role of F-18-fluoride PET/CT, FDG PET/CT and Tc-99m-MDP bone scans in the detection of bone metastases in patients with lung, breast and prostate carcinoma. This was a prospective study including patients for staging (S) and restaging (R). Seventy-two patients (23S, 49R) with infiltrating ductal breast carcinoma, 49 patients (25S, 24R) with prostate adenocarcinoma and 30 patients (17S, 13R) with non-small-cell lung carcinoma (NSCLC), without known bone metastases but with high risk/clinical suspicion for the same, underwent a Tc-99m-MDP bone scan, FDG PET/CT and F-18-fluoride PET/CT within 2 weeks. All scans were reviewed by two experienced nuclear medicine physicians, and the findings were correlated with MRI/thin-slice CT/skeletal survey. Histological verification was done wherever feasible. Sensitivity and negative predictive value (NPV) of F-18-fluoride PET/CT was 100 % in all three malignancies, while that of FDG PET/CT was 79 % and 73 % in NSCLC, 73 % and 80 % in breast cancer and 72 and 65 % in prostate cancer. Specificity and positive predictive value (PPV) of FDG PET/CT were 100 % in NSCLC and prostate and 97 % and 96 % in breast cancer. As compared to the Tc-99m-MDP bone scan, all parameters were superior for F-18-fluoride PET/CT in prostate and breast cancer, but sensitivity and NPV were equal in NSCLC. The MDP bone scan had superior sensitivity and NPV compared to FDG PET/CT but had low specificity and PPV. To rule out bone metastases in cases where there is a high index of suspicion, F-18-fluoride PET/CT is the most reliable investigation. F-18-fluoride PET/CT has the potential to replace the Tc-99m-MDP bone scan for the detection of bone metastases.