title: Intratumoural heterogeneity measured using FDG PET and MRI is associated with tumour-stroma ratio and clinical outcome in head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  To evaluate the association between the tumour-stroma ratio and intratumoural heterogeneity measured using 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) and magnetic resonance imaging (MRI), and further investigate the prognostic significance of imaging biomarkers in head and neck squamous cell carcinoma (HNSCC).
  
  
  METHODS
  Textural-based imaging parameters of the primary tumour were extracted in 44 patients. In addition, the difference between the minimum and maximum apparent diffusion coefficient (ADC) values (ADCdiff) was calculated on MRI. The relationships between the tumour-stroma ratio and imaging parameters were evaluated. The associations between imaging parameters and recurrence-free survival (RFS) were assessed using Cox proportional hazard regression models.
  
  
  RESULTS
  Coarseness (r=-0.382) on PET and ADCdiff (r=0.534) on MRI were significantly correlated with the proportion of stroma. The best imaging biomarkers for the 2-year RFS prediction were coarseness (AUC=0.741) and ADCdiff (AUC=0.779). Multivariate analysis showed that coarseness (hazard ratio=10.549, 95% confidence interval=2.544-43.748, p=0.001) was an independent prognostic factor for RFS.
  
  
  CONCLUSIONS
  Heterogeneity imaging parameters are significantly associated with the tumour-stroma ratio. These imaging biomarkers may help to facilitate the risk stratification for tumour recurrence in HNSCC.
authors.affiliation: Department of Radiology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: J W
authors.initials: JW
authors.lastname: Choi
authors.affiliation: Department of Pathology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: D
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: S H
authors.initials: SH
authors.lastname: Hyun
authors.affiliation: Department of Radiology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: M
authors.initials: M
authors.lastname: Han
authors.affiliation: Department of Pathology, Ajou University School of Medicine, Suwon, Republic of Korea.
authors.forename: J-H
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Ajou University School of Medicine, Suwon, Republic of Korea. Electronic address: suesj202@ajou.ac.kr.
authors.forename: S J
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011379:Prognosis; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18