title: The prognostic value of fluorodeoxyglucose positron emission tomography metabolic tumor volume in solitary colorectal liver metastasis.
abstract: BACKGROUND
  Management of colorectal liver metastasis (CRLM) is evolving but surgery remains the most effective treatment in improving survival. Optimal preoperative patient selection is important and semiquantitative F-18 fluorodeoxyglucose positron emission tomography (PET) parameters may provide valuable prognostic information.
  
  
  METHODS
  Sixty-one patients with solitary CRLM as first site of distant dissemination and preoperatively staged with PET were retrospectively studied. Various semiquantitative PET parameters, pathological size of the hepatic lesion and clinical variables were correlated with survival outcome. The data were analyzed with nonparametric Kruskal-Wallis test and univariate Cox regression. Kaplan-Meier estimates of overall survival and disease-free survival (DFS) were log-rank tested.
  
  
  RESULTS
  Mean follow-up for the 61 subjects was 48 months. The 1- and 3-year survival rates were 98.7% and 72.2%. The median DFS was 16 months with recurrence in 10 (16.4%) patients following surgery. Univariate analysis found a statistically significant increased risk of death for higher mean PET tumor diameter (hazard ratio [HR] 2.95, P = 0.014), mean metabolic tumor volume (HR 3.0, P = 0.009) and median pathological size of hepatic lesion (HR 2.97, P = 0.022). Maximum standardized uptake value of the liver metastasis and calculated standardized uptake value ratio between tumor and normal liver parenchyma (tumor background ratio) were not predictive of overall survival. None of the PET parameters or clincopathological variables statistically correlated with DFS.
  
  
  CONCLUSIONS
  Semiquantitative PET variables are potentially valuable prognostic biomarkers in CRLM. Volumetric data like metabolic tumor volume enable better estimation of tumor burden and its utility may improve preoperative risk stratification and optimize outcome.
authors.affiliation: Department of Nuclear Medicine and PET, Sydney, Australia.|University of New South Wales, Kensington, Sydney, Australia.
authors.forename: Yi-Tung T
authors.initials: YT
authors.lastname: Huang
authors.affiliation: University of New South Wales, Kensington, Sydney, Australia.
authors.forename: Joomann
authors.initials: J
authors.lastname: Park
authors.affiliation: University of New South Wales, Kensington, Sydney, Australia.|Epidemiology, Healthy People and Places Unit, Southwestern Sydney Local Health District, Sydney, Australia.
authors.forename: Shanley
authors.initials: S
authors.lastname: Chong
authors.affiliation: Upper GI Surgical Unit, Royal North Shore Hospital and North Shore Private Hospital, St. Leonards, Sydney, Australia.|University of Sydney, Sydney, Australia.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hugh
authors.affiliation: Medical Oncology, Liverpool Hospital, Sydney, Australia.|Ingham Institute for Applied Medical Research, Liverpool, Sydney, Australia.|University of New South Wales, Kensington, Sydney, Australia.|University of Western Sydney, Sydney, Australia.
authors.forename: Weng Leong
authors.initials: WL
authors.lastname: Ng
authors.affiliation: Department of Nuclear Medicine and PET, Sydney, Australia.|University of New South Wales, Kensington, Sydney, Australia.|University of Western Sydney, Sydney, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Lin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: PET/CT; colorectal cancer; liver metastasis; prognosis; surgery