Prospective Study Evaluating Na^sup 18^F PET/CT in Predicting Clinical Outcomes and Survival in Advanced Prostate Cancer

This prospective pilot study evaluated the ability of Na^sup 18^F PET/CT to detect and monitor bone metastases over time and its correlation with clinical outcomes and survival in advanced prostate cancer. Sixty prostate cancer patients, including 30 with and 30 without known bone metastases by conventional imaging, underwent Na^sup 18^F PET/CT at baseline, 6 mo, and 12 mo. Positive lesions were verified on follow-up scans. Changes in SUVs and lesion number were correlated with prostate-specific antigen change, clinical impression, and overall survival. Significant associations included the following: SUV and prostate-specific antigen percentage change at 6 mo (P = 0.014) and 12 mo (P = 0.0005); SUV maximal percentage change from baseline and clinical impression at 6 mo (P = 0.0147) and 6-12 mo (P = 0.0053); SUV change at 6 mo and overall survival (P = 0.018); number of lesions on Na^sup 18^F PET/CT and clinical impression at baseline (P < 0.0001), 6 mo (P = 0.0078), and 12 mo (P = 0.0029); and number of lesions on Na^sup 18^F PET/CT per patient at baseline and overall survival (P = 0.017). In an exploratory analysis, paired ^sup 99m^Tc-methylene diphosphonate bone scans (^sup 99m^Tc-BS) were available for 35 patients at baseline, 19 at 6 mo, and 14 at 12 mo (68 scans). Malignant lesions on Na^sup 18^F PET/CT (n = 57) were classified on ^sup 99m^Tc-BS as malignant 65% of the time, indeterminate 25% of the time, and negative 10% of the time. Additionally, 69% of paired scans showed more lesions on Na^sup 18^F PET/CT than on ^sup 99m^Tc-BS. The baseline number of malignant lesions and changes in SUV on follow-up Na^sup 18^F PET/CT significantly correlate with clinical impression and overall survival. Na^sup 18^F PET/CT detects more bone metastases earlier than ^sup 99m^Tc-BS and enhances detection of new bone disease in high-risk patients.