11C-Acetate PET Imaging of Prostate Cancer

11C-Acetate can act as a probe of tissue metabolism through entry into catabolic or anabolic metabolic pathways as medi-ated by acetyl–coenzyme A. The uptake of 11C-acetate in pros-tate cancer was investigated to determine whether this tracer has potential in tumor identification. Methods: Twenty-two pa-tients with prostate cancer underwent PET after intravenous administration of 740 MBq 11C-acetate. Eighteen of the 22 patients were also investigated with 18F-FDG PET. Standardized uptake values (SUVs) for each tumor were investigated for tracer activity at 10–20 min after 11C-acetate and 40–60 min after 18F-FDG administration. Results: Adenocarcinoma of the prostate showed variable uptake of 11C-acetate, with SUVs ranging from 3.27 to 9.87. In contrast, SUVs for 18F-FDG ranged from 1.97 to 6.34. By visual inspection, 11C-acetate accumula-tion in primary prostate tumors was positive in all patients, whereas 18F-FDG accumulation was positive in only 15 of 18 patients. 11C-Acetate PET in a patient with lymph node metas-tasis showed high intrapelvic accumulation corresponding to metastatic sites. Similarly, 2 patients with bone metastases were 11C-acetate avid. Conclusion: 11C-Acetate shows marked uptake in prostate cancer and is more sensitive in detection of prostate cancer than is 18F-FDG PET. 11C-Acetate represents a new tracer for detection of prostate cancer with PET, measuring radiopharmaceutical uptake pathways that are different from those measured by 18F-FDG