title: [11C]choline PET/CT imaging in occult local relapse of prostate cancer after radical prostatectomy.
abstract: OBJECTIVE
  The aim of this study was to assess the accuracy and clinical impact of [(11)C]choline PET/CT for localizing occult relapse of prostate adenocarcinoma after radical prostatectomy.
  
  
  METHODS
  Fourty-nine patients with prostate adenocarcinoma, radical prostatectomy, no evidence of metastatic disease, and occult relapse underwent [(11)C]choline PET/CT. Thirty-six of the patients had biochemical evidence and histological evaluation of local recurrence. Thirteen patients had PSA < 0.3 ng/ml and no evidence of active disease after 1 year follow-up. Focal nodular [(11)C]choline uptake in the prostatic fossa was visually assessed and graded on a five point scale. Maximum standardized radioactivity uptake value (SUV(max)) and the lesion size were measured. A receiver operating characteristic (ROC) analysis was performed and the clinical impact of the PET/CT study was determined.
  
  
  RESULTS
  [(11)C]choline PET/CT was true positive in 23/33 patients and true negative in 12/13 controls. SUV(max) of local recurrence was 3.0 (median, range 0.6-7.4) and 1.1 (0.4-1.6) in controls (p = 0.0002). Lesion size was 1.7 cm (range 0.9-3.7). Area under the ROC curve for detecting relapse was 0.90 +/- 0.05 and 0.83 +/- 0.06 for visual evaluation and SUV(max), respectively. Sensitivity and specificity of [(11)C]choline PET/CT were 0.73 and 0.88, respectively. [(11)C]choline PET/CT identified 12/17 (71%) patients with a favourable biochemical response to local radiotherapy at 2 year (median, 0.8-3.2 range) follow-up.
  
  
  CONCLUSIONS
  Focally increased [(11)C]choline uptake in the prostatic bed reliably predicted local low volume occult relapsing prostate adenocarcinoma after radical prostatectomy and identified 71% of patients with a favourable biochemical response to local radiotherapy.
authors.affiliation: Klinik für Nuklearmedizin, Universität Ulm, Robert-Koch-Strasse 8, 89081, Ulm, Germany. sven.reske@uniklinik-ulm.de
authors.forename: Sven N
authors.initials: SN
authors.lastname: Reske
authors.forename: Norbert M
authors.initials: NM
authors.lastname: Blumstein
authors.forename: Gerhard
authors.initials: G
authors.lastname: Glatting
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D000368:Aged; D001706:Biopsy; D002250:Carbon Radioisotopes; D002794:Choline / Q000737:chemistry; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D012015:Reference Standards; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed