title: Accumulation of [11C]acetate in normal prostate and benign prostatic hyperplasia: comparison with prostate cancer.
abstract: Carbon-11 acetate positron emission tomography (PET) has been reported to be of clinical value for the diagnosis of prostate cancer. However, no detailed analysis has yet been carried out on the physiological accumulation of [(11)C]acetate in the prostate. The purpose of this study was to elucidate the physiological accumulation of [(11)C]acetate in the prostate using dynamic PET. The study included 30 subjects without prostate cancer [21 with normal prostate and nine with benign prostatic hyperplasia (BPH)] and six patients with prostate cancer. A dynamic PET study was performed for 20 min after intravenous administration of 555 MBq of [(11)C]acetate. The standardised uptake value (SUV) at 16-20 min post tracer administration and the early-to-late-activity ratio of the SUV (E/L ratio), which was determined by dividing the SUV(6-10 min) by the SUV(16-20min), were calculated to evaluate the accumulation of [(11)C]acetate. The prostate was clearly visualised and distinguished from adjacent organs in PET images in most of the cases. The SUV of the prostate (2.6+/-0.8) was significantly higher than that of the rectum (1.7+/-0.4) or bone marrow (1.3+/-0.3) ( P<0.0001 in each case). The SUV of the normal prostate of subjects aged <50 years (3.4+/-0.7) was significantly higher than both the SUV for the normal prostate of subjects aged > or =50 years (2.3+/-0.7) and that of subjects with BPH (2.1+/-0.6) ( P<0.01 in each case). The primary prostate cancer in six cases was visualised by [(11)C]acetate PET. However, the difference in the SUV between subjects aged > or =50 with normal prostate or with BPH and the patients with prostate cancer (1.9+/-0.6) was not statistically significant. There was also no significant difference in the E/L ratio between subjects aged > or =50 with normal prostate (0.98+/-0.04) or BPH (0.96+/-0.08) and patients with prostate cancer (1.02+/-0.12). In conclusion, a normal prostate exhibits age-related physiological accumulation of [(11)C]acetate. Careful interpretation of [(11)C]acetate PET images of prostate cancer is necessary because the SUV and the E/L ratio for the normal prostate and for BPH overlap significantly with those for prostate cancer.
authors.affiliation: Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 6, Kita-ku, Sapporo 060-8638, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kato
authors.forename: Eriko
authors.initials: E
authors.lastname: Tsukamoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kuge
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takei
authors.forename: Tohru
authors.initials: T
authors.lastname: Shiga
authors.forename: Nobuo
authors.initials: N
authors.lastname: Shinohara
authors.forename: Chietsugu
authors.initials: C
authors.lastname: Katoh
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Nakada
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
mesh_terms: D000085:Acetates / Q000493:pharmacokinetics*; D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000378:metabolism; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon / Q000493:pharmacokinetics*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D009928:Organ Specificity; D011467:Prostate / Q000000981:diagnostic imaging / Q000378:metabolism*; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D000085:Acetates; D019275:Radiopharmaceuticals; C438206:carbon-11 acetate; D002244:Carbon