title: Influence of hormonal therapy in prostate cancer patients undergoing [18F]fluoromethyl choline PET/CT: a retrospective study.
abstract: BACKGROUND
  Patients with suspected recurrence of prostate cancer undergoing [18F]fluoromethyl choline ([18F]FCH) PET/CT were retrospectively evaluated to investigate the influence of hormonal therapy (HT) in [18F]FCH uptake.
  
  
  METHODS
  [18F]FCH PET/CT was performed in 102 surgically treated patients with suspected recurrence (PSA increase >0.2 ng/mL) of prostate cancer, divided in two groups: under HT (N.=54) and without HT (N.=48) at the time of PET scanning. PET/CT was carried out by an integrated system (Biograph 6, CTI/Siemens, Knoxville, TN, USA) intravenously by administering 4.1 MBq/kg of [18F]FCH to each patient; images were acquired 60 minutes later.
  
  
  RESULTS
  On the total number of patients, 66 were found to be true positives (TP), 9 false positives (FP), 5 false negatives (FN) and 22 true negatives (TN), sensitivity to [18F]FCH PET/CT was 93%, specificity 71%, accuracy 86%, positive predictive value (PPV) 88%, negative predictive value (NPV) 81%. In the 54 patients under HT, 38 were TP, 6 FP, 3 FN and 7 TN, sensitivity was 93%, specificity 54%, accuracy 83%, PPV 86% and NPV was 70%. In the 48 patients receiving no HT, 28 were TP, 3 FP, 2 FN and 15 TN, sensitivity was 93%, specificity 83%, accuracy 90%, PPV 90% and NPV 88%. A χ2 test showed that sensitivity, accuracy and PPV did not differ among patients with and without HT, while specificity and NPV were significantly lower (P<0.001) in HT treated patients.
  
  
  CONCLUSIONS
  Sensitivity, accuracy and PPV were similar in patients with and without HT. Specificity and NPV were reduced in patients under HT, but further data are necessary to support if this reduction is casual or related to therapy and it could be confirmed in a larger series of patients.
authors.affiliation: Section of Nuclear Medicine and Medical Physics, Department of Surgical and Biomedical Sciences, University of Perugia, Perugia, Italy - barbara.palumbo@unipg.it.
authors.forename: Barbara
authors.initials: B
authors.lastname: Palumbo
authors.forename: Silvio
authors.initials: S
authors.lastname: Sivolella
authors.forename: Isabella
authors.initials: I
authors.lastname: Palumbo
authors.forename: Tommaso
authors.initials: T
authors.lastname: Buresta
authors.forename: Valentina
authors.initials: V
authors.lastname: Radicchia
authors.forename: Mario L
authors.initials: ML
authors.lastname: Fravolini
authors.forename: Francesca
authors.initials: F
authors.lastname: Ferretti
authors.forename: Rita
authors.initials: R
authors.lastname: Bellavita
authors.forename: Luigi
authors.initials: L
authors.lastname: Mearini
authors.forename: Michele
authors.initials: M
authors.lastname: Scialpi
authors.forename: Cynthia
authors.initials: C
authors.lastname: Aristei
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Pelliccia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport / Q000187:drug effects; D002794:Choline / Q000031:analogs & derivatives* / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D012008:Recurrence; D012189:Retrospective Studies
chemical_list: D006728:Hormones; C516370:fluoromethylcholine; D002794:Choline