title: [11C]Acetate positron emission tomography-computed tomography imaging of prostate cancer lymph-node metastases correlated with histopathological findings after extended lymphadenectomy.
abstract: OBJECTIVE
  The aim of this study was to determine the efficacy of combined [(11)C]acetate positron emission tomography and computed tomography ([(11)C]acetate-PET/CT) in regional lymph-node staging in patients with prostate cancer (PCa).
  
  
  METHODS
  [(11)C]Acetate-PET/CT was performed in 19 PCa patients who subsequently underwent extended pelvic lymph-node dissection (ePLND). The [(11)C]acetate-PET/CT results were compared with the surgical and histopathological findings from 13 defined lymph-node regions.
  
  
  RESULTS
  [(11)C]Acetate-PET/CT was true-positive for lymph-node metastases in nine patients, false-positive in three, false-negative in one patient and true-negative in six. The patient-by-patient-based sensitivity was 90% and the specificity 67%, the positive predictive value (PPV) was 75% and the negative predictive value (NPV) 86%. From a total of 114 nodal regions (mean 5.9 regions per patient), 484 lymph nodes (mean 25.5 nodes per patient) were removed and evaluated histopathologically. Forty-six lymph nodes from 24 out of 114 (21%) nodal regions were positive for PCa metastasis. The nodal-region-based sensitivity of [(11)C]acetate-PET/CT was 62%, specificity was 89%, PPV 62% and NPV 89%.
  
  
  CONCLUSIONS
  [(11)C]Acetate-PET/CT detects PCa lymph-node metastases with high patient-by-patient-based sensitivity but low specificity, and low nodal-region-based sensitivity but high specificity. Its limited ability to detect microscopic lymph-node involvement makes ePLND essential in all patients diagnosed with positive nodes on [(11)C]acetate-PET/CT.
authors.affiliation: Department of Urology, Molecular Medicine and Surgery, Karolinska Institutet, Section of Urology, Karolinska University Hospital , Stockholm , Sweden.
authors.forename: Martin C
authors.initials: MC
authors.lastname: Schumacher
authors.forename: Eva
authors.initials: E
authors.lastname: Radecka
authors.forename: Magnus
authors.initials: M
authors.lastname: Hellström
authors.forename: Hans
authors.initials: H
authors.lastname: Jacobsson
authors.forename: Anders
authors.initials: A
authors.lastname: Sundin
mesh_terms: D000085:Acetates; D000368:Aged; D002250:Carbon Radioisotopes; D015331:Cohort Studies; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000601:surgery; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D000085:Acetates; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals
keywords: PET/CT; [11C]acetate; lymph-node metastases; lymphadenectomy; prostate cancer