title: Diagnostic and prognostic value of 18F-FDG PET/CT for patients with suspected recurrence from squamous cell carcinoma of the esophagus.
abstract: Patients with esophageal squamous cell carcinoma (ESCC) are commonly at high risk of recurrence within 2 y after initial treatment. The aim of this study was to evaluate the role of 18F-FDG PET/CT in patients with possibly recurrent ESCC who underwent definitive treatment.
  
  
  METHODS
  Fifty-six patients with previously treated ESCC underwent PET/CT scans. The PET/CT findings were validated by histopathology or clinical follow-up of at least 6 mo. The sensitivity, specificity, and accuracy of PET/CT for detecting recurrence were calculated. Comparison of the standardized uptake value (SUV) was performed between patients grouped according to their status at the last follow-up (relapsed or relapse-free, alive or dead). The overall survival rates were estimated by the Kaplan-Meier method. The Cox proportional hazards model was used to evaluate independent prognostic variables for both univariate and multivariate survival analysis.
  
  
  RESULTS
  Forty-five (80.4%) patients had recurrence in 72 (66.1%) malignant sites. On PET/CT, there were 9 false-positive and 5 false-negative results. The overall sensitivity, specificity, and accuracy of PET/CT for detecting recurrence at all sites were 93.1% (67/72), 75.7% (28/37), and 87.2% (95/109), respectively. PET/CT was highly sensitive, specific, and accurate at regional and distant sites. At local sites, sensitivity was high, but specificity was lower (50%) because of a high incidence of false-positive findings. Patients who were confirmed with recurrence or who had died at the last follow-up had higher SUVs (P = 0.027 and <0.001, respectively). In multivariate survival analysis, therapeutic modality (hazard ratio = 0.437; P = 0.044), SUV (hazard ratio = 1.071; P = 0.029), and disease status on PET/CT (hazard ratio = 2.430; P = 0.045) were independent significant prognostic predictors for overall survival. The Kaplan-Meier survival curves indicated poor prognostic outcome in subgroup patients with higher SUVs or systemic disease on PET/CT.
  
  
  CONCLUSIONS
  18F-FDG PET/CT is highly effective for detecting recurrent ESCC. The relatively low specificity at local sites is associated primarily with a high rate of false-positive interpretations at anastomoses. PET/CT can also provide noninvasive and independent prognostic information using SUV and recurrent disease pattern on PET/CT images for previously treated ESCC.
authors.affiliation: Department of Thoracic Surgery, Shandong Cancer Hospital and Institute, Jinan, Shandong Province, China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Guo
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
authors.forename: Yan
authors.initials: Y
authors.lastname: Xi
authors.forename: Baijiang
authors.initials: B
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Jiandong
authors.initials: J
authors.lastname: Zhang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Fu
authors.forename: Guoren
authors.initials: G
authors.lastname: Yang
authors.forename: Shuanghu
authors.initials: S
authors.lastname: Yuan
authors.forename: Jinming
authors.initials: J
authors.lastname: Yu
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000401:mortality; D004938:Esophageal Neoplasms / Q000175:diagnosis* / Q000401:mortality; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D049268:Positron-Emission Tomography / Q000379:methods*; D011379:Prognosis; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019788:Fluorodeoxyglucose F18