title: Intraductal US in assessing the effects of radiation therapy and prediction of patency of metallic stents in extrahepatic bile duct carcinoma.
abstract: BACKGROUND
  We assessed the local effects of radiation therapy using intraductal ultrasonography (US) to predict the subsequent patency of metallic stents in bile duct carcinoma.
  
  
  METHODS
  Data from 16 patients with extrahepatic-suprapancreatic bile duct carcinoma were prospectively analyzed. Thin-caliber US probes (2.0 mm diameter/20 MHz frequency and 2.8 mm diameter/10 MHz frequency) were inserted into the bile duct via a percutaneous transhepatic approach pre- and postradiation therapy to evaluate the effects of treatment. When intraductal US showed a reduction in bile duct wall thickness of 30% or greater or showed a lessening of vessel (portal vein or right hepatic artery) invasion, radiation therapy was judged to be effective. Noncovered metallic stents were then inserted, and their patency was evaluated over time.
  
  
  RESULTS
  When radiation therapy was effective (n = 7), the metallic stent was patent for 522 +/- 571 days. When radiation was ineffective (n = 9), the metallic stent was patent for only 188 +/- 159 days. When radiation therapy was ineffective, stent obstruction occurred in 6 of 9 (66.7%) patients during this period, significantly more frequently than when radiation therapy was effective (14.3%, p < 0.05).
  
  
  CONCLUSIONS
  Assessment of local radiation effects by intraductal US is useful for predicting patency of metallic stents in bile duct cancer.
authors.affiliation: Departments of Gastroenterology and Radiology, Jichi Medical School, Yakushiji, Tochigi, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tamada
authors.forename: S
authors.initials: S
authors.lastname: Wada
authors.forename: A
authors.initials: A
authors.lastname: Ohashi
authors.forename: T
authors.initials: T
authors.lastname: Tomiyama
authors.forename: Y
authors.initials: Y
authors.lastname: Satoh
authors.forename: T
authors.initials: T
authors.lastname: Miyata
authors.forename: K
authors.initials: K
authors.lastname: Ido
authors.forename: M
authors.initials: M
authors.lastname: Nakazawa
authors.forename: K
authors.initials: K
authors.lastname: Sugano
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy* / Q000628:therapy; D017734:Bile Ducts, Extrahepatic / Q000000981:diagnostic imaging*; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010166:Palliative Care / Q000379:methods; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D015607:Stents; D014654:Vascular Patency