title: 18F-choline and/or 11C-acetate positron emission tomography: detection of residual or progressive subclinical disease at very low prostate-specific antigen values (<1 ng/mL) after radical prostatectomy.
abstract: OBJECTIVE
  To assess the value of positron emission tomography (PET)/computed tomography (CT) with either (18)F-choline and/or (11)C-acetate, of residual or recurrent tumour after radical prostatectomy (RP) in patients with a prostate-specific antigen (PSA) level of <1 ng/mL and referred for adjuvant or salvage radiotherapy.
  
  
  METHODS
  In all, 22 PET/CT studies were performed, 11 with (18)F-choline (group A) and 11 with (11)C-acetate (group B), in 20 consecutive patients (two undergoing PET/CT scans with both tracers). The median (range) PSA level before PET/CT was 0.33 (0.08-0.76) ng/mL. Endorectal-coil magnetic resonance imaging (MRI) was used in 18 patients. Nineteen patients were eligible for evaluation of biochemical response after salvage radiotherapy.
  
  
  RESULTS
  There was abnormal local tracer uptake in five and six patients in group A and B, respectively. Except for a single positive obturator lymph node, there was no other site of metastasis. In the two patients evaluated with both tracers there was no pathological uptake. Endorectal MRI was locally positive in 15 of 18 patients; 12 of 19 responded with a marked decrease in PSA level (half or more from baseline) 6 months after salvage radiotherapy.
  
  
  CONCLUSIONS
  Although (18)F-choline and (11)C-acetate PET/CT studies succeeded in detecting local residual or recurrent disease in about half the patients with PSA levels of <1 ng/mL after RP, these studies cannot yet be recommended as a standard diagnostic tool for early relapse or suspicion of subclinical minimally persistent disease after surgery. Endorectal MRI might be more helpful, especially in patients with a low likelihood of distant metastases. Nevertheless, further research with (18)F-choline and/or (11)C-acetate PET with optimal spatial resolution might be needed for patients with a high risk of distant relapse after RP even at low PSA values.
authors.affiliation: Service of Radiation Oncology, University Hospital, Geneva, Switzerland. Hansjorg.Vees@hcuge.ch
authors.forename: Hansjörg
authors.initials: H
authors.lastname: Vees
authors.forename: Franz
authors.initials: F
authors.lastname: Buchegger
authors.forename: Susanne
authors.initials: S
authors.lastname: Albrecht
authors.forename: Haleem
authors.initials: H
authors.lastname: Khan
authors.forename: Daniela
authors.initials: D
authors.lastname: Husarik
authors.forename: Habib
authors.initials: H
authors.lastname: Zaidi
authors.forename: Dmitri
authors.initials: D
authors.lastname: Soloviev
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Hany
authors.forename: Raymond
authors.initials: R
authors.lastname: Miralbell
mesh_terms: D000085:Acetates; D000368:Aged; D002250:Carbon Radioisotopes; D002794:Choline; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000532:radiotherapy; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging / Q000532:radiotherapy / Q000601:surgery; D049268:Positron-Emission Tomography / Q000379:methods*; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy / Q000601:surgery; D019275:Radiopharmaceuticals; D016879:Salvage Therapy / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D000085:Acetates; D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D017430:Prostate-Specific Antigen; D002794:Choline