title: 18F-FDG-PET/CT can identify histopathological non-responders to platinum-based neoadjuvant chemotherapy in advanced epithelial ovarian cancer.
abstract: OBJECTIVE
  The aim of this study was to examine the relationship between the reduction of maximum standardized uptake values (SUVmax) in 18F-FDG-PET/CT to histopathological changes obtained with neoadjuvant chemotherapy (NACT) in advanced epithelial ovarian cancer (EOC). We wanted to evaluate whether 18F-FDG-PET/CT is useful for identifying patients who will not respond to NACT and would therefore benefit from second-line chemotherapy instead of interval debulking surgery (IDS).
  
  
  METHODS
  Twenty-six primarily inoperable EOC patients treated with NACT were enrolled in this study. 18F-FDG-PET/CT imaging was performed before diagnostic laparoscopy and after three to four NACT cycles. The relationship between the decrease in omental SUVmax from before to after NACT with omental histopathological response was examined in samples taken from the corresponding anatomical sites during IDS. Patients were divided into three groups according to chemotherapy-induced histopathological changes. Serum CA125 and HE4 halftimes during NACT as well as Ki-67 antigen expression in IDS samples were determined.
  
  
  RESULTS
  The median omental SUVmax change during NACT was -64% (range-16% to -84%), and it was associated with histopathological response (p=0.004, OR 0.9, CI 0.84-0.97). A SUVmax decrease of less than 57% identified histopathological non-responders. Progression-free survival (PFS) differed between the poor, moderate and good histopathological response groups (0.9 year vs. 1.2 years vs. 1.4 years, respectively, p=0.05). The SUVmax change was not associated with PFS.
  
  
  CONCLUSIONS
  18F-FDG-PET/CT was able to identify patients who would not respond to NACT. To obtain a histopathological response in EOC, a substantial metabolic response in 18F-FDG-PET/CT is necessary.
authors.affiliation: Department of Obstetrics and Gynecology, Turku University Hospital, University of Turku, Finland. Electronic address: tuulia.vallius@utu.fi.
authors.forename: Tuulia
authors.initials: T
authors.lastname: Vallius
authors.affiliation: Department of Pathology, Turku University Hospital, University of Turku, Finland.
authors.forename: Anniina
authors.initials: A
authors.lastname: Peter
authors.affiliation: Department of Obstetrics and Gynecology, Turku University Hospital, University of Turku, Finland; Department of Obstetrics and Gynecology, Tampere University Hospital, Finland.
authors.forename: Annika
authors.initials: A
authors.lastname: Auranen
authors.affiliation: Department of Pathology, Turku University Hospital, University of Turku, Finland; Auria biobank, Turku University Hospital, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Carpén
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Turku PET Centre, Turku University Hospital, University of Turku, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Kemppainen
authors.affiliation: Department of Pediatrics, Turku University Hospital, University of Turku, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Matomäki
authors.affiliation: Department of Obstetrics and Gynecology, Satakunta Central Hospital, Finland.
authors.forename: Sinikka
authors.initials: S
authors.lastname: Oksa
authors.affiliation: Department of Pathology, Turku University Hospital, University of Turku, Finland.
authors.forename: Pia
authors.initials: P
authors.lastname: Roering
authors.affiliation: Department of Clinical Physiology and Nuclear Medicine, Turku PET Centre, Turku University Hospital, University of Turku, Finland.
authors.forename: Marko
authors.initials: M
authors.lastname: Seppänen
authors.affiliation: Department of Obstetrics and Gynecology, Turku University Hospital, University of Turku, Finland.
authors.forename: Seija
authors.initials: S
authors.lastname: Grénman
authors.affiliation: Department of Obstetrics and Gynecology, Turku University Hospital, University of Turku, Finland.
authors.forename: Johanna
authors.initials: J
authors.lastname: Hynninen
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000077216:Carcinoma, Ovarian Epithelial; D017024:Chemotherapy, Adjuvant; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000032:analysis*; D006801:Humans; D015233:Models, Statistical; D064847:Multimodal Imaging / Q000379:methods; D020360:Neoadjuvant Therapy; D009375:Neoplasms, Glandular and Epithelial / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000032:analysis*; D012044:Regression Analysis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D009944:Organoplatinum Compounds; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: (18)F-FDGPET/CT; Epithelial ovarian cancer; Histopathological response; Neoadjuvant chemotherapy; Treatment response evaluation