title: Interim FDG PET/CT for predicting the outcome in patients with head and neck cancer.
abstract: OBJECTIVE
  The study aimed to investigate the prognostic effects of interim (18) fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (PET/CT) during definitive radiotherapy (RT) or chemoradiotherapy (CRT) in patients with head and neck cancer.
  
  
  METHODS
  This is a prospectively treatment study.
  
  
  METHODS
  The pretreatment and interim PET/CT images of 51 patients with advanced pharyngeal cancers receiving definitive RT/CRT were evaluated prospectively. The interim PET/CT images were taken at a cumulative RT dose ranging from 41.4 to 46.8 Gy. The maximum standardized uptake value (SUVm) of the interim PET/CT and the reduction ratio of the SUVm (SRR) between the two images were measured. The differences between patients with or without local failures were examined using the Mann-Whitney test. Overall survival (OS), disease-free survival (DFS), and primary and nodal relapse-free survival rates were calculated using the Kaplan-Meier method. Independent prognosticators were identified using Cox regression analysis.
  
  
  RESULTS
  After a median follow-up duration of 23 months, a higher interim SUVm was associated with local failures. Conducting a multivariate analysis revealed that a SUVmax reduction ratio of primary tumor (SRR-P) < 0.64 was associated with the inferior OS (hazard ratio 2.64; P =0.035) and DFS (hazard ratio 2.33; P = 0.045). Patients who had tumors with an SRR-P < 0.64 had a considerably lower 2-year OS and DFS compared with those who had SRR-P ≥ 0.64 (47% vs. 66%; 41% vs. 64%).
  
  
  CONCLUSIONS
  A higher interim SUVm was associated with local recurrence. In addition, patients with a lower SRR-P should be considered to be at risk of primary failure.
  
  
  METHODS
  4.
authors.affiliation: Department of Radiation Oncology, China Medical University, Taichung; School of Medicine, China Medical University, Taichung; School of Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Shang-Wen
authors.initials: SW
authors.lastname: Chen
authors.forename: Te-Chun
authors.initials: TC
authors.lastname: Hsieh
authors.forename: Kuo-Yang
authors.initials: KY
authors.lastname: Yen
authors.forename: Shih-Neng
authors.initials: SN
authors.lastname: Yang
authors.forename: Yao-Ching
authors.initials: YC
authors.lastname: Wang
authors.forename: Chun-Ru
authors.initials: CR
authors.lastname: Chien
authors.forename: Ji-An
authors.initials: JA
authors.lastname: Liang
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000628:therapy; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis; D009367:Neoplasm Staging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D000077195:Squamous Cell Carcinoma of Head and Neck; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18Fluoro-2-deoxy-D-glucose; PET/CT; chemoradiotherapy; head and neck cancer; response marker