title: 11C-Acetate PET/CT in localized prostate cancer: a study with MRI and histopathologic correlation.
abstract: This work characterizes the uptake of (11)C-acetate in prostate cancer (PCa), benign prostate hyperplasia, and normal prostate tissue in comparison with multiparametric MRI, whole-mount histopathology, and clinical markers to evaluate the potential utility of (11)C-acetate for delineating intraprostatic tumors in a population of patients with localized PCa.
  
  
  METHODS
  Thirty-nine men with presumed localized PCa underwent dynamic-static abdominal-pelvic (11)C-acetate PET/CT for 30 min and 3-T multiparametric MRI before prostatectomy. PET/CT images were registered to MR images using pelvic bones for initial rotation-translation, followed by manual adjustments to account for prostate motion and deformation from the MRI endorectal coil. Whole-mount pathology specimens were sectioned using an MRI-based patient-specific mold resulting in improved registration between the MRI, PET, and pathology. (11)C-acetate PET standardized uptake values were compared with multiparametric MRI and pathology.
  
  
  RESULTS
  (11)C-acetate uptake was rapid but reversible, peaking at 3-5 min after injection and reaching a relative plateau at approximately 10 min. The average maximum standardized uptake value (10-12 min) of tumors was significantly higher than that of normal prostate tissue (4.4 ± 2.05 [range, 1.8-9.2] vs. 2.1 ± 0.94 [range, 0.7-3.4], respectively; P < 0.001); however, it was not significantly different from that of benign prostatic hyperplasia (4.8 ± 2.01 [range, 1.8-8.8]). A sector-based comparison with histopathology, including all tumors greater than 0.5 cm, revealed a sensitivity and specificity of 61.6% and 80.0%, respectively, for (11)C-acetate PET/CT and 82.3% and 95.1%, respectively, for MRI. The (11)C-acetate accuracy was comparable to that of MRI when only tumors greater than 0.9 cm were considered. In a small cohort (n = 9), (11)C-acetate uptake was independent of fatty acid synthase expression using immunohistochemistry.
  
  
  CONCLUSIONS
  (11)C-acetate PET/CT demonstrates higher uptake in tumor foci than in normal prostate tissue; however, (11)C-acetate uptake in tumors is similar to that in benign prostate hyperplasia nodules. Although (11)C-acetate PET/CT is not likely to have utility as an independent modality for evaluation of localized PCa, the high uptake in tumors may make it useful for monitoring focal therapy when tissue damage after therapy may limit anatomic imaging methods.
authors.affiliation: Molecular Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
authors.forename: Esther
authors.initials: E
authors.lastname: Mena
authors.forename: Baris
authors.initials: B
authors.lastname: Turkbey
authors.forename: Haresh
authors.initials: H
authors.lastname: Mani
authors.forename: Stephen
authors.initials: S
authors.lastname: Adler
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Valera
authors.forename: Marcelino
authors.initials: M
authors.lastname: Bernardo
authors.forename: Vijay
authors.initials: V
authors.lastname: Shah
authors.forename: Thomas
authors.initials: T
authors.lastname: Pohida
authors.forename: Yolanda
authors.initials: Y
authors.lastname: McKinney
authors.forename: Gideon
authors.initials: G
authors.lastname: Kwarteng
authors.forename: Dagane
authors.initials: D
authors.lastname: Daar
authors.forename: Maria L
authors.initials: ML
authors.lastname: Lindenberg
authors.forename: Philip
authors.initials: P
authors.lastname: Eclarinal
authors.forename: Revia
authors.initials: R
authors.lastname: Wade
authors.forename: W Marston
authors.initials: WM
authors.lastname: Linehan
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Merino
authors.forename: Peter A
authors.initials: PA
authors.lastname: Pinto
authors.forename: Peter L
authors.initials: PL
authors.lastname: Choyke
authors.forename: Karen A
authors.initials: KA
authors.lastname: Kurdziel
mesh_terms: D000085:Acetates / Q000378:metabolism; D000328:Adult; D000368:Aged; D001692:Biological Transport; D014408:Biomarkers, Tumor / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D000085:Acetates; D014408:Biomarkers, Tumor; C438206:carbon-11 acetate; D002244:Carbon