CHAPTER 3 VISUALIZATION AND QUANTIFICATION OF UPTAKE OF 11C-ACETATE IN PROSTATE CANCER AND IN BENIGN PROSTATIC HYPERPLASIA WITH PET.

BACKGROUND AND OBJECTIVE: Visualization of prostate cancer with positron emission tomography (PET) using 2-[18F]-2-deoxy-D-Glucose (FDG) as radiopharmaceutical is limited by the low uptake of FDG in the tumor and by radioactivity excreted into the bladder. More specific PET radiopharmaceuticals would be welcome. Carbon-11 labeled acetate (ACET) is a radiopharmaceutical generally used for cardiac PET as it represents oxidative metabolism. ACET PET has recently been proposed for tumor imaging of prostate cancer. We studied the imaging and uptake of 11C-acetate in prostate cancer and in benign prostatic hyperplasia using ACET PET. METHODS: Twelve patients with histologically proven prostate cancer and five patients with benign hyperplasia of the prostate were included. PET images were performed with an ECAT HR+ using 800 MBq ACET. Data acquisition was started at 5 minutes post injection. Attenuation-corrected images were evaluated visually. Standardized uptake values (SUV) were calculated of the benign prostate gland and of prostate cancer. RESULTS: The benign prostate was visualized with a SUV of 2.8 ± 0.9 (mean ± SD). The primary tumor could be visualized with a SUV of 3.6 ± 1.5 (mean ± SD). The difference in uptake was not significant. Non-specific uptake of ACET was noticed in the intestines and in the bone marrow. Little to no radioactivity in the bladder was observed. CONCLUSION: Carbon-11 labeled acetate is avidly taken up in both prostate cancer and in benign prostates. It poorly discriminates cancer from benign prostatic hyperplasia. Non specific uptake is seen in intestine and bone marrow. These results could confine clinical application of ACET PET as a metabolic imaging technique in prostate cancer