title: Absolute CT perfusion parameter values after the neoadjuvant chemoradiotherapy of the squamous cell esophageal carcinoma correlate with the histopathologic tumor regression grade.
abstract: OBJECTIVE
  To analyze value of the computed tomography (CT) perfusion imaging in response evaluation of the esophageal carcinoma to neoadjuvant chemoradiotherapy (nCRT) using the histopathology as reference standard.
  
  
  METHODS
  Forty patients with the squamous cell esophageal carcinoma were re-evaluated after the nCRT by CT examination, which included low-dose CT perfusion study that was analyzed using the deconvolution-based CT perfusion software (Perfusion 3.0, GE). Histopathologic assessment of tumor regression grade (TRG) according to Mandard's criteria served as reference standard of response evaluation. Statistical analysis was performed using Spearman's rank correlation coefficient (r(S)) and Kruskal-Wallis's test.
  
  
  RESULTS
  The perfusion CT parameter values, measured after the nCRT in the segment of the esophagus that had been affected by neoplasm prior to therapy, significantly correlated with the TRG: blood flow (BF) (r(S)=0.851; p<0.001), blood volume (BV) (r(S)=0.732; p<0.001) and mean transit time (MTT) (r(S)=-0.386; p=0.014). Median values of BF and BV significantly differed among TRG 1-4 groups (p<0.001), while maximal esophageal wall thickness did not (p=0.102). Median BF and BV were gradually rose and MTT decreased as TRG increased, from 21.4 ml/min/100 g (BF), 1.6 ml/100 g (BV) and 8.6 s (MTT) in TRG 1 group, to 37.3 ml/min/100 g, 3.5 ml/100 g and 7.5 s in TRG 2 group, 81.4 ml/min/100 g, 4.1 ml/100 g and 3.8 s in TRG 3 group, and 121.1 ml/min/100 g, 4.9 ml/100 g and 3.7 s in TRG 4 group. In all 15 patients who achieved complete histopathologic regression (TRG 1), BF was <30.0 ml/min/100 g.
  
  
  CONCLUSIONS
  CT perfusion could improve the accuracy in response evaluation of the esophageal carcinoma to nCRT.
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Department of Digestive Radiology (First Surgery University Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade, Serbia. Electronic address: avstefan@eunet.rs.
authors.forename: A
authors.initials: A
authors.lastname: Djuric-Stefanovic
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Department of Pathology, First Surgery University Clinic, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: M
authors.initials: M
authors.lastname: Micev
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Clinic for Radiation Oncology and Diagnostics, Department of Radiation Oncology, Institute of Oncology and Radiology of Serbia, Belgrade, Serbia.
authors.forename: S
authors.initials: S
authors.lastname: Stojanovic-Rundic
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia; First Surgery University Clinic, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: P
authors.initials: P
authors.lastname: Pesko
authors.affiliation: Faculty of Medicine, University of Belgrade, Belgrade, Serbia; Department of Digestive Radiology (First Surgery University Clinic), Center of Radiology and MR, Clinical Center of Serbia, Belgrade, Serbia.
authors.forename: Dj
authors.initials: Dj
authors.lastname: Saranovic
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000628:therapy* / Q000648:ultrastructure; D059186:Chemoradiotherapy, Adjuvant; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy* / Q000648:ultrastructure; D000077277:Esophageal Squamous Cell Carcinoma; D004947:Esophagus / Q000000981:diagnostic imaging / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
keywords: CT perfusion; Esophageal carcinoma; Neoadjuvant chemoradiotherapy; Response evaluation; Tumor regression grade