Correlation of 11C-Choline PET, histopathology and PSA levels in prostate cancer patients undergoing neoadjuvant docetaxel chemotherapy

  • A/Prof Ian Davis, Ludwig Oncology Unit, Austin Hospital, Victoria, Australia
  • Dr Sze Ting Lee, Centre for PET, Ludwig Institute for Cancer Research, Department of Medicine, Austin Hospital, Victoria, Australia
  • A/Prof Damien Bolton, Department of Surgery & Urology, University of Melbourne, Austin Hospital, Victoria, Australia
  • Dr David Clouston, Department of Pathology, Austin Hospital, Victoria, Australia
  • Dr Dragan Damianovich, Austin Hospital, Victoria, Australia
  • Dr Carmel Pezaro, Ludwig Oncology Unit, Austin Hospital, Victoria, Australia
  • Mr David Angus, Department of Urology, Austin Hospital, Victoria, Australia
  • Ms Trish Jenkins, Austin Hospital, Victoria, Australia
  • Dr Chun Yew Fong, Austin Hospital, Australia
  • Dr Andrew Scott, Austin Health, Ludwig Institute for Cancer Research, University of Melbourne, Australia

    • Background: Docetaxel is effective treatment in castrate-resistant prostate carcinoma (PC), however currently no factors that predict response are known. This study aimed to assess correlation between 11C-Choline PET and known prognostic factors of prostate specific antigen (PSA) and Gleason score.

    Methods: Patients with confirmed localized prostate adenocarcinoma suitable for radical prostatectomy (RP) were recruited into this prospective pilot study. Response to chemotherapy was assessed by change in PSA, Gleason score or 11C-choline (CHOL) and 18F-fluorodeoxyglucose (FDG) PET scans. PET scans were assessed visually and using SUVmax. Routine CT pelvis and serum PSA was performed. FDG and CHOL PET scans were performed prior to administration of two cycles of docetaxel given 3-weekly. Both PET scans and serum PSA were repeated prior to RP. Gleason score and histological findings on the RP specimen were correlated with PET scans and pre-treatment TRUS biopsies.

    Results: Ten patients with a median age of 63 years (range 52-68 year old) were enrolled and completed all study requirements. CHOL PET showed good to excellent correlation with RP pathology in all ten patients, but FDG PET showed poor correlation with primary PC. Small non-significant decreases in PSA between baseline and week 6 were observed, and histology showed subtle changes, with no confluent tumor necrosis or scarring related to therapy.

    Conclusions: CHOL PET shows excellent localization to tumour and correlates with the small median increase in PSA post-chemotherapy, and may be useful as a marker to assess treatment response in PC. No correlation was found with FDG PET.