title: Prostate-specific antigen kinetics parameters are predictive of positron emission tomography features worsening in patients with biochemical relapse after prostate cancer treatment with radical intent: Results from a longitudinal cohort study.
abstract: OBJECTIVE
  The aim of this study was to identify prostate-specific antigen (PSA) kinetics parameters predictive of [(18)F]fluorocholine positron emission tomography/computed tomography ((18)FC PET/CT) features worsening in a cohort of patients with biochemical failure after prostate cancer treatment.
  
  
  METHODS
  This longitudinal cohort study comprised 103 consecutive patients. All patients underwent two (18)FC PET/CT scans: one at baseline (PET1) and one after 6 months (PET2). Total PSA (tPSA), PSA velocity (vPSA), PSA doubling time (PSAdt), absolute variation in PSA values between PET2 and PET1 (ΔPSA), and percentage variation in PSA between the two PSA measurements (PSA%) were measured in each patient. Progression of disease on (18)FC PET/CT findings was compared with the PSA kinetics parameters. The major outcome measure was disease progression at PET2.
  
  
  RESULTS
  (18)FC PET/CT progression between PET1 and PET2 was reported in 64 patients (62.1%), while in 39 cases it remained unvaried. The following PSA kinetic parameters correlated with worsened (18)FC PET/CT findings: ΔPSA >5 ng/ml [odds ratio (OR = 6.44, 95% confidence interval (CI) 1.04-39.6; p = 0.04], vPSA >6 ng/ml/month (OR = 5.2, 95% CI 0.9-29.8; p = 0.05) and PSAdt <6 months (OR = 5.2, 95% CI 0.4-5.4; p = 0.03). From receiver operating characteristics (ROC) analysis, the combination with the three PSA kinetics parameters for predicting worsened (18)FC PET/CT findings resulted in a sensitivity of 86% (95% CI 77-92%) and specificity of 77% (95% CI 65-85%).
  
  
  CONCLUSIONS
  PSA kinetics is strictly related to (18)FC PET/CT findings. In patients with biochemical relapse, ΔPSA >5 ng/ml, PSAdt <6 months and vPSA >6 ng/ml/month are highly predictive of (18)FC PET/CT features worsening, independently from the treatment received.
authors.affiliation: Department of Urology.
authors.forename: Mauro
authors.initials: M
authors.lastname: Gacci
authors.forename: Tommaso
authors.initials: T
authors.lastname: Cai
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Siena
authors.forename: Andrea
authors.initials: A
authors.lastname: Minervini
authors.forename: Mozhgan Fayaz
authors.initials: MF
authors.lastname: Torshizi
authors.forename: Matteo
authors.initials: M
authors.lastname: Bartolini
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giannì
authors.forename: Calogero
authors.initials: C
authors.lastname: Saieva
authors.forename: Mauro
authors.initials: M
authors.lastname: Ceroti
authors.forename: Beatrice
authors.initials: B
authors.lastname: Detti
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Livi
authors.forename: Alberto
authors.initials: A
authors.lastname: Pupi
authors.forename: Marco
authors.initials: M
authors.lastname: Carini
mesh_terms: D000368:Aged; D002794:Choline / Q000031:analogs & derivatives; D015331:Cohort Studies; D018450:Disease Progression; D006801:Humans; D007610:Kallikreins / Q000378:metabolism*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery; D049268:Positron-Emission Tomography; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000601:surgery; D012372:ROC Curve; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; C514960:fluorocholine; C549870:KLK3 protein, human; D007610:Kallikreins; D017430:Prostate-Specific Antigen; D002794:Choline
keywords: ROC curve; biochemical failure; positron emission tomography; prostate neoplasm; prostate-specific antigen