title: Prostate-specific antigen and prostate-specific antigen velocity as threshold indicators in 11C-acetate PET/CTAC scanning for prostate cancer recurrence.
abstract: OBJECTIVE
  The aim of this study was to identify which patient characteristics are associated with the highest likelihood of positive findings on 11C-acetate PET/computed tomography attenuation correction (CTAC) (PET/CTAC) scan when imaging for recurrent prostate cancer.
  
  
  METHODS
  From 2007 to 2011, 250 11C-acetate PET/CTAC scans were performed at a single institution on patients with prostate cancer recurrence after surgery, brachytherapy, or external beam radiation. Of these patients, 120 met our inclusion criteria. Logistic regression analysis was used to examine the relationship between predictability of positive findings and patients' characteristics, such as prostate-specific antigen (PSA) level at the time of scan, PSA kinetics, Gleason score, staging, and type of treatment before scan.
  
  
  RESULTS
  In total, 68.3% of the 120 11C-acetate PET/CTAC scans were positive. The percentage of positive scans and PSA at the time of scanning and PSA velocity (PSAV) had positive correlations. The putative sensitivity and specificity were 86.6% and 65.8%, respectively, when a PSA level greater than 1.24 ng/mL was used as the threshold for scanning. The putative sensitivity and specificity were 74% and 75%, respectively, when a PSAV level greater than 1.32 ng/mL/y was used as the threshold. No significant associations were found between scan positivity and age, PSA doubling time, Gleason score, staging, or type of treatment before scanning.
  
  
  CONCLUSIONS
  This retrospective study suggests that threshold models of PSA greater than 1.24 ng/mL or PSAV greater than 1.32 ng/mL per year are independent predictors of positive findings in 11C-acetate PET/CTAC imaging of recurrent prostate cancer.
authors.affiliation: From the *Department of Radiology, and †Department of Preventive Medicine and Public Health, University of Kansas Medical Center, Kansas City, KS; ‡Southwest Oncology Centers, Scottsdale, AZ; §Department of Urology, and ¶Department of Hematology and Oncology, University of Kansas Medical Center, Kansas City, KS.
authors.forename: Reginald W
authors.initials: RW
authors.lastname: Dusing
authors.forename: Warner
authors.initials: W
authors.lastname: Peng
authors.forename: Sue-Min
authors.initials: SM
authors.lastname: Lai
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Grado
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Holzbeierlein
authors.forename: J Brantley
authors.initials: JB
authors.lastname: Thrasher
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Hill
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Van Veldhuizen
mesh_terms: D000368:Aged; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000000981:diagnostic imaging; D049268:Positron-Emission Tomography; D017430:Prostate-Specific Antigen / Q000592:standards*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging; D012016:Reference Values; D014057:Tomography, X-Ray Computed
chemical_list: D017430:Prostate-Specific Antigen