title: Salvage radiotherapy in prostate cancer patients. Planning, treatment response and prognosis using (11)C-choline PET/CT.
abstract: OBJECTIVE
  To assess the prognostic value of the therapeutic response by (11)C-choline PET/CT in prostate cancer patients with biochemical recurrence in which (11)C-choline PET/CT indicated radio-guided radiotherapy.
  
  
  METHODS
  The study included 37 patients initially treated with prostatectomy, who were treated due to biochemical recurrence. (11)C-choline PE/CT detected infra-diaphragmatic lymph-node involvement. All were selected for intensity modulated radiation therapy, escalating the dose according to the PET findings. One year after treatment patients underwent PSA and (11)C-choline PET/CT categorizing response (complete/partial/progression). Clinical/biochemical/image monitoring was performed until appearance of second relapse or 36 months in disease-free patients.
  
  
  RESULTS
  (11)C-choline PET/CT could detect lymph nodes in all 37 patients. They were 18 (48.6%) of more than a centimetre in size and 19 (51.3%) with no pathological CT morphology: 9 (24.3%) with positive lymph nodes of around one centimetre and 10 (27.0%) only less than a centimetre in size. The response by (11)C-choline PET/CT was categorised one year after radiotherapy: 16 patients (43.2%) complete response; 15 (40.5%) partial response, and 6 (16.2%) progression. The response was concordant between the PSA result and (11)C-choline PET/CT in 32 patients (86.5%), and discordant in five (13.5%). New recurrence was detected in 12 patients (80%) with partial response, and 5 (31.2%) with complete response. The mean time to recurrence was 9 months after partial response, and 18 months after complete response (significant difference, p<.0001).
  
  
  CONCLUSIONS
  (11)C-choline PET/CT allows the selection of patients with recurrent prostate cancer candidates for radiotherapy and to plan the technique. The evaluation of therapeutic response by (11)C-choline PET/CT has prognostic significance.
authors.affiliation: Unidad PET/TC, CETIR, ERESA, Esplugues, Barcelona, España. Electronic address: jrgarcia@cetir.es.
authors.forename: J R
authors.initials: JR
authors.lastname: García
authors.affiliation: Unidad PET/TC, CETIR, ERESA, Esplugues, Barcelona, España.
authors.forename: M
authors.initials: M
authors.lastname: Cozar
authors.affiliation: Unidad PET/TC, CETIR, ERESA, Esplugues, Barcelona, España.
authors.forename: M
authors.initials: M
authors.lastname: Soler
authors.affiliation: Unidad PET/TC, CETIR, ERESA, Esplugues, Barcelona, España.
authors.forename: P
authors.initials: P
authors.lastname: Bassa
authors.affiliation: Unidad PET/TC, CETIR, ERESA, Esplugues, Barcelona, España.
authors.forename: E
authors.initials: E
authors.lastname: Riera
authors.affiliation: Unidad PET/TC, CETIR, ERESA, Esplugues, Barcelona, España.
authors.forename: J
authors.initials: J
authors.lastname: Ferrer
mesh_terms: D002250:Carbon Radioisotopes; D002794:Choline; D006801:Humans; D008297:Male; D000072078:Positron Emission Tomography Computed Tomography; D011379:Prognosis; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D011880:Radiotherapy Planning, Computer-Assisted; D016879:Salvage Therapy
chemical_list: D002250:Carbon Radioisotopes; D002794:Choline
keywords: (11)C-choline PET/CT; (11)C-colina PET/TC; Biochemical recurrence; Cáncer de próstata; Prognostic significance; Prostate cancer; Radio-guided radiotherapy; Radioterapia radioguiada; Recidiva bioquímica; Respuesta terapia; Significación pronóstica; Treatment response