Metabolic imaging of untreated prostate cancer by positron emission tomography with (18)fluorine-labeled deoxyglucose

Purpose: We evaluated positron emission tomography (PET) with (18)fluorine (F-18)-labeled deoxyglucose for metabolic grading of untreated primary prostate cancer, and differentiation of benign and malignant prostatic disease. Materials and Methods: A total of 48 patients with untreated prostate cancer of different stages and 16 with histologically confirmed benign prostatic hyperplasia (BPH) underwent static PET after intravenous injection of 150 to 300 MBq. F-18-deoxyglucose. F-18-deoxyglucose accumulation was quantitated by calculating differential uptake ratios and prostate-to-skeletal muscle ratios. Results: Low F-18-deoxyglucose uptake was noted in the majority of primary tumors (81%). F-18-deoxyglucose accumulation did not correlate with increasing tumor grade or stage, There was a significant overlap in uptake values in BPH and malignant prostatic disease. A trend towards statistical significance was noted with lower prostate-to-skeletal muscle ratios in patients with BPH (p <0.07). Increased F-18-deoxyglucose accumulation was detected in some patients with BPH and malignant prostatic disease, as well as in those with lymph node and bone metastases of prostate cancer. Conclusions: F-18-deoxyglucose PET does not allow for metabolic labeling in the majority of untreated primary prostate cancers. BPH and primary prostate cancer cannot be reliably differentiated on the basis of PET. Increased F-18-deoxyglucose accumulation occurs in some primary prostate tumors and in metastatic deposits of prostate cancer.