The Increased Accumulation of [18F]Fluorodeoxyglucose in Untreated Prostate Cancer

Background: To evaluate the clinical usefulness of [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) compared with histopathological grading, clinical stage and serum prostatic specific antigen (PSA) level in the detection and characterization of prostate cancer. Methods: Forty-four patients with histologically proven prostate cancer and five control subjects with benign prostatic hyperplasia (BPH) were prospectively investigated with FDG-PET prior to treatment. Results: By visual inspection, FDG accumulation was positive in 28 patients with prostate cancer (sensitivity 64%), whereas all were negative in the control group. FDG-PET in three patients with lymph node metastases did not show any high intrapelvic accumulations corresponding to metastatic sites. Among 12 patients with multiple bone metastases which were detected with 99m-HMDP bone scintigraphy, nine (75%) showed moderate to high FDG accumulation at the sites of bone metastases. Quantitatively, FDG accumulation in prostate cancer was significantly higher than in BPH and there was a tendency for FDG uptake of tumors to be higher with higher histological Gleason grades. Furthermore, FDG uptake in tumors with lymph node and/or bone metastasis was significantly higher than that of localized stages. However, the correlation between PSA and FDG uptake in the prostate cancer was very weak for clinical relevance. Conclusions: Although FDG-PET was not sensitive enough to detect prostate cancer in clinical use, it is suggested that glucose metabolism in prostate cancer tended to be higher in patients with tumors of advanced stages.