title: FDG-PET/CT as prognostic factor and surveillance tool for postoperative radiation recurrence in locally advanced head and neck cancer.
abstract: OBJECTIVE
  To evaluate the prognostic value of metabolic tumor volume (MTV) and maximum standardized uptake value (SUVmax) on initial positron emission tomography-computed tomography (PET-CT) and investigate the clinical value of SUVmax for early detection of locoregional recurrent disease after postoperative radiotherapy in patients with locally advanced head and neck squamous cell carcinoma (HNSCC).
  
  
  METHODS
  A total of 100 patients with locally advanced HNSCC received primary tumor excision and neck dissection followed by adjuvant radiotherapy with or without chemotherapy. The MTV and SUVmax were measured from primary sites and neck nodes. The prognostic value of MTV and SUVmax were assessed using initial staging PET/CT (study A). Follow-up PET/CT scan available after postoperative concurrent chemoradiotherapy or radiotherapy were evaluated for the SUVmax value and correlated with locoregional recurrence (study B). A receiver operating characteristic (ROC) curve analysis was used to define a threshold value of SUVmax with the highest accuracy for recurrent disease assessment.
  
  
  RESULTS
  High MTV (>41 mL) is negative prognostic factor for disease free survival (p = 0.041). Postradiation SUVmax was significantly correlated with locoregional recurrence (hazard ratio, 1.812; 95% confidence interval, 1.361 to 2.413; p < 0.001). A cut-off value of 5.38 from follow-up PET/CT was identified as having maximal accuracy for detecting locoregional recurrence by ROC analysis.
  
  
  CONCLUSIONS
  MTV at staging work-up was significantly associated with disease free survival. The SUVmax value from follow-up PET/CT showed high diagnostic accuracy for the detection of locoregional recurrence in postoperatively irradiated HNSCC.
authors.affiliation: Department of Radiation Oncology, The Catholic University of Korea School of Medicine, Seoul, Korea.
authors.forename: Giwon
authors.initials: G
authors.lastname: Kim
authors.forename: Yeon Sil
authors.initials: YS
authors.lastname: Kim
authors.forename: Eun Ji
authors.initials: EJ
authors.lastname: Han
authors.forename: Ie Ryung
authors.initials: IeR
authors.lastname: Yoo
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Song
authors.forename: Sang-Nam
authors.initials: SN
authors.lastname: Lee
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Byung-Oak
authors.initials: BO
authors.lastname: Choi
authors.forename: Hong-Seok
authors.initials: HS
authors.lastname: Jang
authors.forename: Sei-Chul
authors.initials: SC
authors.lastname: Yoon