title: Ineffectiveness of ¹⁸F-fluorodeoxyglucose positron emission tomography in the evaluation of tumor response after completion of neoadjuvant chemoradiation in esophageal cancer.
abstract: OBJECTIVE
  To evaluate the role of ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) in the assessment of tumor response after the completion of neoadjuvant chemoradiation (CRT) in patients with locally advanced resectable esophageal cancer.
  
  
  BACKGROUND
  After primary CRT, a noninvasive evaluation of the tumor response could help in the treatment decision to identify patients who may benefit from surgery. Whether FDG-PET provides clinically relevant information remains questionable.
  
  
  METHODS
  Operable patients with locally advanced esophageal cancer (clinically staged T3 N0-1 M0) were enrolled in this prospective study. The complete treatment plan included neoadjuvant CRT (cisplatin + 5-fluorouracil/45 Gy) followed 6 to 8 weeks later by a transthoracic en bloc esophagectomy. Morphological evaluation combined with FDG-PET was performed 2 weeks before the start of CRT and 4 to 6 weeks after the completion of CRT. Intratumoral pre- and posttreatment FDG-standardized uptake values (SUV1, SUV2, percentage change) were assessed. These variables were correlated with pathological and morphologic responses and survival. Investigators were blinded to the FDG-PET results unless they revealed metastatic disease.
  
  
  RESULTS
  Of 60 total patients, 46 underwent the complete treatment plan (median age: 60.1 years; adenocarcinoma: 25 patients; squamous cell cancer: 21 patients). A major pathological response occurred in 45.7% of patients and was associated with a favorable outcome (P = 0.057). Neoadjuvant CRT led to a significant reduction in intratumoral FDG-uptake (P < 0.001). No significant association was seen between a pathological response (either complete or major) and the FDG-PET results (P > 0.280). The SUV2 value was correlated with a morphological response and the possibility to perform an R0 resection (P < 0.018; receiver operating characteristic curve analysis: SUV2 threshold = 5.5). No significant association was found between metabolic imaging and recurrence or survival.
  
  
  CONCLUSIONS
  FDG-PET does not effectively correlate with pathological response and long-term survival in patients with locally advanced esophageal cancer undergoing neoadjuvant CRT followed by surgery. (Registered on the www.e-cancer RECF0350.).
authors.affiliation: Department of Digestive and Oncological Surgery, University Hospital of Lille, Lille, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Piessen
authors.forename: Grégory
authors.initials: G
authors.lastname: Petyt
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.forename: Xavier
authors.initials: X
authors.lastname: Mirabel
authors.forename: Damien
authors.initials: D
authors.lastname: Huglo
authors.forename: Christophe
authors.initials: C
authors.lastname: Mariette
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D059248:Chemoradiotherapy; D002945:Cisplatin / Q000008:administration & dosage; D003627:Data Interpretation, Statistical; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D016629:Esophagectomy / Q000379:methods; D005260:Female; D019788:Fluorodeoxyglucose F18; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002945:Cisplatin; D005472:Fluorouracil