title: Usefulness of positron emission tomography for assessing the response of neoadjuvant chemoradiotherapy in patients with esophageal cancer.
abstract: BACKGROUND
  In this study, we retrospectively assessed the performance of 18-F-fluorodeoxyglucose positron emission tomography (FDG-PET) compared with computed tomography (CT) and esophagography for assessing the response of advanced esophageal squamous cell carcinoma (SCC) to neoadjuvant chemoradiotherapy.
  
  
  METHODS
  We studied 10 patients with thoracic esophageal SCC who received neoadjuvant chemoradiotherapy followed by surgery. Tumor response was assessed by CT, endoscopy, esophagography and FDG-PET before and after neoadjuvant treatment.
  
  
  RESULTS
  Assessment of the rate of decrease in standardized uptake value (SUV) revealed a partial response (more than 50% decrease) in 5 (50%) of the patients, and assessment of length decrease of FDG uptake showed a partial response in 9 (90%) of the patients. Comparison of the histological response and the rate of decrease of various parameters revealed significant associations between histological response and tumor length (P <0.05), SUV after neoadjuvant therapy (P <0.05), and reduction in the extent of FDG uptake (P <0.01). However histological response was not significantly correlated with the rate of reduction of SUV, for both CT and esophagography.
  
  
  CONCLUSIONS
  FDG-PET may be of considerable value for predicting the pathologic response of esophageal SCC to neoadjuvant therapy. Despite assessment of SUV before neoadjuvant therapy, low FDG uptake after therapy and reduction in the extent of FDG uptake may provide a reliable assessment of the response to therapy.
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000532:radiotherapy*; D017024:Chemotherapy, Adjuvant; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000532:radiotherapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D014055:Tomography, Emission-Computed; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18