title: Alteration of strain ratio evaluated by transabdominal ultrasound elastography may predict the efficacy of preoperative chemoradiation performed for pancreatic ductal carcinoma: preliminary results.
abstract: OBJECTIVE
  We evaluated the usefulness of ultrasound-elastography (US-elastography) for prediction of therapy effect by measuring strain ratio (SR).
  
  
  METHODS
  Consecutive patients with resectable pancreatic ductal carcinoma who underwent US-elastography before and after neoadjuvant chemoradiation were included. Patients were classified into either response group or non-response group according to the histological evaluation of resected specimens. Serum carbohydrate antigen 19-9 (CA19-9), SR, and maximum standard uptake value (SUVmax) obtained from 18F-fuluoro-deoxy-D-glucose positron emission tomography and computerized tomography were measured before and after chemoradiation. Alteration rate of each parameter was compared between response group and non-response group.
  
  
  RESULTS
  Seven patients met the inclusion criteria. One patient was excluded from pancreatectomy because liver metastasis was found by laparotomy. Serum CA19-9 was not elevated for 2 patients throughout the chemoradiation. Three patients were classified into response group and the remaining three into non-response group. Alteration rate of CA19-9 and SR was shown to be grater in response group (26.83 +/- 19.69 vs. 4.87 +/- 4.25, and 3.61 +/- 2.40 vs. 1.39 +/- 0.20, respectively), whereas that of SUVmax was not (1.56 +/- 0.43 vs. 2.11 +/- 0.10).
  
  
  CONCLUSIONS
  Increase rate of SR may predict the therapy effect of neoadjuvant chemoradiation for patients with pancreatic ductal carcinoma, especially for patients without elevation of tumor markers.
authors.forename: Natsuko
authors.initials: N
authors.lastname: Kawada
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tanaka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uehara
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Katayama
authors.forename: Takuya
authors.initials: T
authors.lastname: Hosoki
authors.forename: Motohisa
authors.initials: M
authors.lastname: Takami
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D059248:Chemoradiotherapy; D015331:Cohort Studies; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18