title: Textural features of pretreatment 18F-FDG PET/CT images: prognostic significance in patients with advanced T-stage oropharyngeal squamous cell carcinoma.
abstract: Previous studies have shown that total lesion glycolysis (TLG) may serve as a prognostic indicator in oropharyngeal squamous cell carcinoma (OPSCC). We sought to investigate whether the textural features of pretreatment (18)F-FDG PET/CT images can provide any additional prognostic information over TLG and clinical staging in patients with advanced T-stage OPSCC.
  
  
  METHODS
  We retrospectively analyzed the pretreatment (18)F-FDG PET/CT images of 70 patients with advanced T-stage OPSCC who had completed concurrent chemoradiotherapy, bioradiotherapy, or radiotherapy with curative intent. All of the patients had data on human papillomavirus (HPV) infection and were followed up for at least 24 mo or until death. A standardized uptake value (SUV) of 2.5 was taken as a cutoff for tumor boundary. The textural features of pretreatment (18)F-FDG PET/CT images were extracted from histogram analysis (SUV variance and SUV entropy), normalized gray-level cooccurrence matrix (uniformity, entropy, dissimilarity, contrast, homogeneity, inverse different moment, and correlation), and neighborhood gray-tone difference matrix (coarseness, contrast, busyness, complexity, and strength). Receiver-operating-characteristic curves were used to identify the optimal cutoff values for the textural features and TLG.
  
  
  RESULTS
  Thirteen patients were HPV-positive. Multivariate Cox regression analysis showed that age, tumor TLG, and uniformity were independently associated with progression-free survival (PFS) and disease-specific survival (DSS). TLG, uniformity, and HPV positivity were significantly associated with overall survival (OS). A prognostic scoring system based on TLG and uniformity was derived. Patients who presented with TLG > 121.9 g and uniformity ≤ 0.138 experienced significantly worse PFS, DSS, and OS rates than those without (P < 0.001, < 0.001, and 0.002, respectively). Patients with TLG > 121.9 g or uniformity ≤ 0.138 were further divided according to age, and different PFS and DSS were observed.
  
  
  CONCLUSIONS
  Uniformity extracted from the normalized gray-level cooccurrence matrix represents an independent prognostic predictor in patients with advanced T-stage OPSCC. A scoring system was developed and may serve as a risk-stratification strategy for guiding therapy.
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
authors.forename: Nai-Ming
authors.initials: NM
authors.lastname: Cheng
authors.forename: Yu-Hua Dean
authors.initials: YH
authors.lastname: Fang
authors.forename: Joseph Tung-Chieh
authors.initials: JT
authors.lastname: Chang
authors.forename: Chung-Guei
authors.initials: CG
authors.lastname: Huang
authors.forename: Din-Li
authors.initials: DL
authors.lastname: Tsan
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
authors.forename: Hung-Ming
authors.initials: HM
authors.lastname: Wang
authors.forename: Chien-Yu
authors.initials: CY
authors.lastname: Lin
authors.forename: Chun-Ta
authors.initials: CT
authors.lastname: Liao
authors.forename: Tzu-Chen
authors.initials: TC
authors.lastname: Yen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D049268:Positron-Emission Tomography; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: FDG PET/CT; HPV; oropharyngeal carcinoma; textural analysis; total lesion glycolysis