title: Chemotherapy response evaluation with FDG-PET in patients with colorectal cancer.
abstract: BACKGROUND
  The aim of this prospective study was to evaluate the value of F-18-fluorodeoxyglucose-positron emission tomography (FDG-PET) for early assessment of chemotherapy response in patients with advanced colorectal cancer.
  
  
  METHODS
  Dynamic FDG-PET was carried out before and at 2 (n = 50) and 6 months (n = 19) after the start of treatment. Quantitative Patlak analysis [metabolic rate of glucose (MRGlu)] and a simplified method to measure glucose metabolism [standardized uptake value (SUV)] were evaluated. The predictive value of changes in glucose metabolism was assessed with Cox proportional regression analysis. Overall survival (OS) and progression-free survival (PFS) were calculated using Kaplan-Meier estimates.
  
  
  RESULTS
  There was an increase in the rates of death (P = 0.049 for DeltaMRGlu PET1-2; P = 0.017 for DeltaSUV PET1-2; P = 0.032 for DeltaMRGlu PET1-3; P = 0.048 for DeltaSUV PET1-3) and progression (P = 0.026 for DeltaMRGlu PET1-2; P = 0.035 for DeltaSUV PET1-2; P = 0.041 for DeltaMRGlu PET1-3; P = 0.081 for DeltaSUV PET1-3) associated with worse response as assessed by PET on Cox proportional regression analysis. The OS and PFS analysis showed a significant predictive value at broad ranges of DeltaMRGlu and DeltaSUV cut-off levels.
  
  
  CONCLUSIONS
  The degree of chemotherapy-induced changes in tumor glucose metabolism is highly predictive for patient outcome. The use of FDG-PET for therapy monitoring seems clinically feasible since simplified methods (SUV) are sufficiently reliable.
authors.affiliation: Department of Nuclear Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. l.degeus-oei@nucmed.umcn.nl
authors.forename: L F
authors.initials: LF
authors.lastname: de Geus-Oei
authors.forename: H W M
authors.initials: HW
authors.lastname: van Laarhoven
authors.forename: E P
authors.initials: EP
authors.lastname: Visser
authors.forename: R
authors.initials: R
authors.lastname: Hermsen
authors.forename: B A
authors.initials: BA
authors.lastname: van Hoorn
authors.forename: Y J L
authors.initials: YJ
authors.lastname: Kamm
authors.forename: P F M
authors.initials: PF
authors.lastname: Krabbe
authors.forename: F H M
authors.initials: FH
authors.lastname: Corstens
authors.forename: C J A
authors.initials: CJ
authors.lastname: Punt
authors.forename: W J G
authors.initials: WJ
authors.lastname: Oyen
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D005069:Evaluation Studies as Topic; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18