title: Necrosis on FDG PET/CT correlates with prognosis and mortality in sarcomas.
abstract: OBJECTIVE
  The purpose of this study was to determine if there is an association between necrosis as identified on staging (18)F-FDG PET/CT and overall survival (OS) and progression-free survival (PFS) in patients with sarcoma.
  
  
  METHODS
  Sixty-six patients with newly diagnosed limb and girdle sarcoma underwent PET/CT at our institution between June 2004 and July 2009 for sarcoma staging before treatment with curative intent. The tumor maximum standardized up-take values (SUVmax), the presence of necrosis, and the volume of necrosis were measured for each primary tumor and correlated with follow-up data. PFS and OS were analyzed using the Kaplan-Meier method. Proportional hazards models were used to estimate hazard ratios.
  
  
  RESULTS
  Median patient age was 49 years, and 51.6% of the patients were men. Sarcomas were categorized as soft tissue (69.2%), bone (23.5%), or other (7.3%). Mean follow-up time was 33.3 months. During the follow-up interval, 53% of patients experienced disease progression, and 40.9% died. There was a statistically significant relationship between the presence of necrosis and OS (by log-rank test, p = 0.001), as well as PFS (by log-rank test, p = 0.0001). Twenty-four-month OS was 96%, 65%, and 38% in patients with tumors with absence necrosis, those with presence of necrosis, and with necrosis volume greater than 50%, respectively. Forty-eight-month OS was 81% in patients with absence of necrosis and 41% in patients with presence of necrosis. Twelve-month PFS was 96%, 60%, and 42% in patients with tumors with absence of necrosis, those with presence of necrosis, and those with necrosis volume greater than 50%, respectively. Twenty-four-month PFS was 83%, 38%, and 22%, respectively, in these groups.
  
  
  CONCLUSIONS
  The presence of necrosis and the volume of necrosis, as identified on the staging FDG PET/CT and after adjusting for SUVmax, are strong independent adverse prognostic factors for disease recurrence and death in patients with limb and girdle sarcomas.
authors.affiliation: Department of Nuclear Medicine, Royal Victoria Hospital, 687 Pine Ave, Montreal, QC H3A 1A1, Canada. rajan.rakheja@gmail.com
authors.forename: Rajan
authors.initials: R
authors.lastname: Rakheja
authors.forename: William
authors.initials: W
authors.lastname: Makis
authors.forename: Rima
authors.initials: R
authors.lastname: Tulbah
authors.forename: Sonia
authors.initials: S
authors.lastname: Skamene
authors.forename: Christina
authors.initials: C
authors.lastname: Holcroft
authors.forename: Ayoub
authors.initials: A
authors.lastname: Nahal
authors.forename: Robert
authors.initials: R
authors.lastname: Turcotte
authors.forename: Marc
authors.initials: M
authors.lastname: Hickeson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009336:Necrosis; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011379:Prognosis; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals; D012509:Sarcoma / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000473:pathology; D015996:Survival Rate; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18