title: To evaluate the treatment response of locally advanced esophageal cancer after preoperative chemoradiotherapy by FDG-PET/CT scan.
abstract: BACKGROUND
  This study was designed to gauge the effectiveness of evaluation of tumor response and prognosis by positron emission tomography with 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) before and after preoperative chemoradiotherapy in patients with esophageal cancer.
  
  
  METHODS
  Forty-nine patients from October 2008 to September 2012 with locally advanced stage esophageal carcinoma, clinical stage T2-4N0-3M0, who underwent preoperative chemoradiotherapy (pre-CRT) followed by esophagectomy were enrolled in our study. All patients underwent two FDG-PET scans to compare those results with the pathologic results. Metabolic response of the primary tumor by the percentage change of the SUVmax/1 hour (ΔSUV) before and after pre-CRT (ΔSUV was calculated as the difference between pre-CRT SUVmax/1 hour and post-CRT SUVmax/1 hour divided by pre-CRT SUVmax/1 hour at esophageal tumor) was evaluated for overall survival (OS), disease free survival (DFS), local recurrence rate, and distant failure free survival (DFFS). Prognostic factors such as age, different regimen of chemotherapy, pathologic stage, FDG-PET stage, endoscopic esophageal tumor length, and ΔSUV were analyzed. The number of highly suspect malignant lymph nodes was calculated by PET when SUVmax/1 hour ≥2.5 and by surgical removal. Sensitivity and specificity of regional lymph node detection by PET were also recorded.
  
  
  RESULTS
  Upon univariate analysis, overall survival rate was related to ΔSUV >60% (p = 0.045), pathological N stage (p = 0.001), and endoscopic total length of esophageal tumor (p = 0.005). The result of FDG-PET scan after pre-CRT had high specificity (96.7%) but low sensitivity (45.8%) in predicting the residual malignant lymph node numbers. The positive and the negative prediction rates were 44% and 96%, respectively. The result of the FDG-PET after pre-CRT showed upstaged in 16 patients (32.6%), downstaged in nine patients (18.3%), and the same stage in 24 patients (48.9%) when compared with the pathologic stage [corrected].
  
  
  CONCLUSIONS
  The change of SUVmax can be a tool for evaluating tumor response after pre-CRT. There is also a trend of good prognosis in overall survival rate when ΔSUV value is >60%.
authors.affiliation: Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Jing-Wen
authors.initials: JW
authors.lastname: Huang
authors.affiliation: Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung, Taiwan, ROC. Electronic address: hlyeh@vghtc.gov.tw.
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Yeh
authors.affiliation: Division of Thoracic Surgery, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Chung-Ping
authors.initials: CP
authors.lastname: Hsu
authors.affiliation: Division of Nuclear Medicine, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Yu-Yu
authors.initials: YY
authors.lastname: Lu
authors.affiliation: Division of Thoracic Surgery, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Cheng-Yen
authors.initials: CY
authors.lastname: Chuang
authors.affiliation: Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Jin-Ching
authors.initials: JC
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Jai-Fu
authors.initials: JF
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, Taichung Veterans General Hospital, Taichung, Taiwan, ROC.
authors.forename: Chen-Fa
authors.initials: CF
authors.lastname: Chang
mesh_terms: D059248:Chemoradiotherapy; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D016629:Esophagectomy; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: PET scan; chemoradiotherapy; esophageal cancer; preoperative; prognosis