title: Correlation between metabolic tumor volume and pathologic tumor volume in squamous cell carcinoma of the oral cavity.
abstract: OBJECTIVE
  To explore the relationship between pathologic tumor volume and volume estimated from different tumor segmentation techniques on (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in oral cavity cancer.
  
  
  METHODS
  Twenty-three patients with squamous cell carcinoma of the oral tongue had PET-CT scans before definitive surgery. Pathologic tumor volume was estimated from surgical specimens. Metabolic tumor volume (MTV) was defined from PET-CT scans as the volume of tumor above a given SUV threshold. Multiple SUV thresholds were explored including absolute SUV thresholds, relative SUV thresholds, and gradient-based techniques.
  
  
  RESULTS
  Multiple MTV's were associated with pathologic tumor volume; however the correlation was poor (R(2) range 0.29-0.58). The ideal SUV threshold, defined as the SUV that generates an MTV equal to pathologic tumor volume, was independently associated with maximum SUV (p=0.0005) and tumor grade (p=0.024). MTV defined as a function of maximum SUV and tumor grade improved the prediction of pathologic tumor volume (R(2)=0.63).
  
  
  CONCLUSIONS
  Common SUV thresholds fail to predict pathologic tumor volume in head and neck cancer. The optimal technique that allows for integration of PET-CT with radiation treatment planning remains to be defined. Future investigation should incorporate biomarkers such as tumor grade into definitions of MTV.
authors.affiliation: Department of Radiation Oncology, Stanford University School of Medicine, United States.
authors.forename: James D
authors.initials: JD
authors.lastname: Murphy
authors.forename: Karen M
authors.initials: KM
authors.lastname: Chisholm
authors.forename: Megan E
authors.initials: ME
authors.lastname: Daly
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Wiegner
authors.forename: Daniel
authors.initials: D
authors.lastname: Truong
authors.forename: Andrei
authors.initials: A
authors.lastname: Iagaru
authors.forename: Peter G
authors.initials: PG
authors.lastname: Maxim
authors.forename: Billy W
authors.initials: BW
authors.lastname: Loo
authors.forename: Edward E
authors.initials: EE
authors.lastname: Graves
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kaplan
authors.forename: Christina
authors.initials: C
authors.lastname: Kong
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D060787:Neoplasm Grading; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D014062:Tongue Neoplasms / Q000378:metabolism / Q000473:pathology*
chemical_list: D019788:Fluorodeoxyglucose F18