title: Adenocarcinomas of the esophagus: response to chemoradiotherapy is associated with decrease of metabolic tumor volume as measured on PET-CT. Comparison to histopathologic and clinical response evaluation.
abstract: OBJECTIVE
  We determined whether evaluation of treatment response is feasible by measuring metabolic tumor volume parameters on 18F-FDG (Fluorodeoxyglucose) PET-CT (Positron emission tomography-Computed tomography). We compared the response evaluation based on metabolic tumor volume parameters to a histopathologic and clinical response evaluation (clinical response criteria: RECIST criteria=Response evaluation criteria in solid tumors, and WHO criteria=World health organization).
  
  
  METHODS
  A total of 51 study subjects with adenocarcinomas (Type I due to Siewert classification) of the esophagus underwent PET-CT scans before and after neoadjuvant chemoradiotherapy. Tumor volume, maximum and mean standardized uptake values (SUV) were assessed before and after chemoradiotherapy. Furthermore, the total lesion glycolysis (TLG) was calculated by multiplying the tumor volume by the mean SUV of the volume. Clinical response evaluation was performed with endoscopic ultrasound and CT using RECIST and WHO criteria. The reference standard for treatment response was the postsurgical histopathology.
  
  
  RESULTS
  The decrease of tumor volume between the pre- and post-treatment PET-CT scans was a better predictor of histopathologic response and survival than the decrease of the SUV and of the clinical response evaluation based on RECIST and WHO criteria. The highest accuracy, however, was achieved when using the TLG for the identification of treatment responders. A decrease of the TLG by > 78% between pre- and post-therapy scans predicted histopathologic response with a sensitivity and specificity of 91% and 93%, respectively.
  
  
  CONCLUSIONS
  Tumor volume and TLG can be used to assess treatment response and survival in patients with esophageal adenocarcinoma.
authors.affiliation: Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. johannes@roedl@gmail.com
authors.forename: Johannes B
authors.initials: JB
authors.lastname: Roedl
authors.forename: Rivka R
authors.initials: RR
authors.lastname: Colen
authors.forename: Nagaraj S
authors.initials: NS
authors.lastname: Holalkere
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Fischman
authors.forename: Noah C
authors.initials: NC
authors.lastname: Choi
authors.forename: Michael A
authors.initials: MA
authors.lastname: Blake
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D000368:Aged; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019788:Fluorodeoxyglucose F18