title: [(18)F]FDG-PET/CT metabolic parameters as useful prognostic factors in cervical cancer patients treated with chemo-radiotherapy.
abstract: BACKGROUND
  To compare the prognostic value of different anatomical and functional metabolic parameters determined using [(18)F]FDG-PET/CT with other clinical and pathological prognostic parameters in cervical cancer (CC).
  
  
  METHODS
  Thirty-eight patients treated with standard curative doses of chemo-radiotherapy (CRT) underwent pre- and post-therapy [(18)F]FDG-PET/CT. [(18)F]FDG-PET/CT parameters including mean tumor standardized uptake values (SUV), metabolic tumor volume (MTV) and tumor glycolytic volume (TGV) were measured before the start of CRT. The post-treatment tumor metabolic response was evaluated. These parameters were compared to other clinical prognostic factors. Survival curves were estimated by using the Kaplan-Meier method. Cox regression analysis was performed to determine the independent contribution of each prognostic factor.
  
  
  RESULTS
  After 37 months of median follow-up (range, 12-106), overall survival (OS) was 71 % [95 % confidence interval (CI), 54-88], disease-free survival (DFS) 61 % [95 % CI, 44-78] and loco-regional control (LRC) 76 % [95 % CI, 62-90]. In univariate analyses the [(18)F]FDG-PET/CT parameters unfavorably influencing OS, DFS and LRC were pre-treatment TGV-cutoff ≥562 (37 vs. 76 %, p = 0.01; 33 vs. 70 %, p = 0.002; and 55 vs. 83 %, p = 0.005, respectively), mean pre-treatment tumor SUV cutoff ≥5 (57 vs. 86 %, p = 0.03; 36 vs. 88 %, p = 0.004; 65 vs. 88 %, p = 0.04, respectively) and a partial tumor metabolic response after treatment (9 vs. 29 %, p = 0.0008; 0 vs. 83 %, p < 0.0001; 22 vs. 96 %, p < 0.0001, respectively). After multivariate analyses a partial tumor metabolic response after treatment remained as an independent prognostic factor unfavorably influencing DFS and LRC (RR 1:7.7, p < 0.0001, and RR 1:22.6, p = 0.0003, respectively) while the pre-treatment TGV-cutoff ≥562 negatively influenced OS and DFS (RR 1:2, p = 0.03, and RR 1:2.75, p = 0.05).
  
  
  CONCLUSIONS
  Parameters capturing the pre-treatment glycolytic volume and metabolic activity of [(18)F]FDG-positive disease provide important prognostic information in patients with CC treated with CRT. The post-therapy [(18)F]FDG-PET/CT uptake (partial tumor metabolic response) is predictive of disease outcome.
authors.affiliation: Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Fernanda G
authors.initials: FG
authors.lastname: Herrera
authors.affiliation: Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Breuneval
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: John O
authors.initials: JO
authors.lastname: Prior
authors.affiliation: Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Jean
authors.initials: J
authors.lastname: Bourhis
authors.affiliation: Department of Radiation Oncology, Lausanne University Hospital, Lausanne, Switzerland. mahmut.ozsahin@chuv.ch.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Ozsahin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy; D002945:Cisplatin / Q000627:therapeutic use; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006019:Glycolysis; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D064847:Multimodal Imaging; D015999:Multivariate Analysis; D049268:Positron-Emission Tomography; D011379:Prognosis; D016016:Proportional Hazards Models; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*
chemical_list: D019788:Fluorodeoxyglucose F18; D002945:Cisplatin
keywords: Cervical cancer; Chemo-radiotherapy; Standard uptake value; Tumor glycolytic volume; [18F]FDG-PET/CT