title: Value of Intratumoral Metabolic Heterogeneity and Quantitative 18F-FDG PET/CT Parameters to Predict Prognosis in Patients With HPV-Positive Primary Oropharyngeal Squamous Cell Carcinoma.
abstract: OBJECTIVE
  The aim of this study was to evaluate the impact of intratumoral metabolic heterogeneity and quantitative FDG PET/CT imaging parameters for predicting patient outcomes in primary oropharyngeal squamous cell cancer (OPSCC).
  
  
  METHODS
  We retrospectively investigated 105 patients with HPV-positive OPSCC. SUVmax and metabolic tumor volume (MTV) were measured for the primary tumors and when available for the metastatic sites. Primary tumor intratumoral metabolic heterogeneity was calculated as the area under a cumulative SUV volume histograms curve (AUC-CSH). The median follow-up time was 35.4 months (range, 3-92 months). Outcome end point was event-free survival (EFS). Kaplan-Meier survival plots and Cox regression analyses were performed.
  
  
  RESULTS
  Of the 105 patients included, 19 patients relapsed and 11 deceased during the study period. AUC-CSH indexes were associated with EFS using PET gradient-based (P = 0.034) and 50% threshold (P = 0.02) segmentation methods, on multivariate analysis. Kaplan-Meier survival analysis using optimum cutoff of 16.7 SUVmax and 12.7 mL total MTV were significant predictors of EFS. Combining SUVmax and AUC-CSH index in 3 subgroups, patients with higher intratumoral heterogeneity and higher SUVmax were associated with worse outcome (log-rank, P = 0.026). Similarly, patients with higher intratumoral heterogeneity tumors and higher MTV had worse prognosis (log-rank, P = 0.022).
  
  
  CONCLUSIONS
  Intratumoral metabolic heterogeneity using FDG PET was a prognostic factor for EFS in patients with primary HPV (+) OPSCC. The combined predictive effect of FDG avidity, metabolic tumor burden, and intratumoral heterogeneity provided prognostic survival information in these patients.
authors.affiliation: From the *Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins School of Medicine, Baltimore, MD; †Department of Radiology, ‡Department Clinical Sciences, §Advanced Imaging Research Center, and ∥Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX.
authors.forename: Esther
authors.initials: E
authors.lastname: Mena
authors.forename: Mehdi
authors.initials: M
authors.lastname: Taghipour
authors.forename: Sara
authors.initials: S
authors.lastname: Sheikhbahaei
authors.forename: Abhinav K
authors.initials: AK
authors.lastname: Jha
authors.forename: Arman
authors.initials: A
authors.lastname: Rahmim
authors.forename: Lilja
authors.initials: L
authors.lastname: Solnes
authors.forename: Rathan M
authors.initials: RM
authors.lastname: Subramaniam
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D000072078:Positron Emission Tomography Computed Tomography; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D016019:Survival Analysis
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18