title: Intraluminal 192Ir brachytherapy following transjugular intrahepatic portosystemic shunt revision: long-term results and radiotherapy parameters.
abstract: OBJECTIVE
  The stenosis or occlusion of transjugular intrahepatic portosystemic shunt (TIPS) occurs in up to 75% of patients within 12 months after treatment. The aim of our investigation was to evaluate the feasibility, safety and efficacy of intraluminal high-dose rate brachytherapy (HDRBT) with Iridium-192 following TIPS revision to prevent restenosis due to pseudointimal hyperplasia.
  
  
  METHODS
  Between September and November 1996, intraluminal BT was performed in five patients after TIPS revision. The indications for initial TIPS were a Budd-Chiari syndrome in two female patients and recurrent variceal bleeding by alcoholic liver cirrhosis in three male patients. TIPS was created with Wallstents (10 mm diameter in four patients) and Palmaz stent (10 mm diameter in one patient). The re-dilatation was done in all five patients 6 months after first stenting because of restenosis (>50% stent lumen reduction) or occlusion of the stent. A 5-French closed-tip, noncentered BT delivery catheter was used for subsequent radiotherapy. The whole length of the stent and performed dilatation (interventional length - IL) was taken as clinical target length (CTL). A 10-mm safety margin was added proximal and distal to the CTL due to uncertainties of BT source positioning, so forming the planning target length (PTL). To ensure that prescribed dose covers the whole PTL, the active source length (ASL) was 5 mm longer proximal and distal than PTL, so forming the reference isodose length (RIL). A dose of 12 Gy was prescribed in 3 mm distance from the source axis in the mid-plane of the applicator for three patients and in 5 mm distance for two patients.
  
  
  RESULTS
  A normal patency (<50% lumen reduction) of the stent was achieved at 44 months follow-up (duplex sonography+portography) in all three patients with liver cirrhosis, whereas further revisions were necessary in two patients with Budd-Chiari syndrome (after 5.5 and 18 months). No acute, subacute or late brachytherapy (BT)-related side effects were seen until now.
  
  
  CONCLUSIONS
  HDRBT following TIPS revision was safe and feasible in all patients. The exact impact of BT on the TIPS patency should be evaluated in larger clinical trials. Moderate dose escalation and use of today's commercially available centering radiation catheters seem to be necessary.
authors.affiliation: Department of Radiotherapy and Radiobiology, University of Vienna, General Hospital of Vienna, Waehringer Guertel 18-20, Vienna 1090, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Pokrajac
authors.forename: M
authors.initials: M
authors.lastname: Cejna
authors.forename: J
authors.initials: J
authors.lastname: Kettenbach
authors.forename: S
authors.initials: S
authors.lastname: Schamp
authors.forename: C
authors.initials: C
authors.lastname: Fellner
authors.forename: W
authors.initials: W
authors.lastname: Seitz
authors.forename: J
authors.initials: J
authors.lastname: Lammer
authors.forename: R
authors.initials: R
authors.lastname: Poetter
mesh_terms: D000328:Adult; D001918:Brachytherapy / Q000009:adverse effects*; D006502:Budd-Chiari Syndrome / Q000150:complications; D003251:Constriction, Pathologic / Q000517:prevention & control* / Q000532:radiotherapy*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use*; D008104:Liver Cirrhosis, Alcoholic / Q000150:complications; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D019168:Portasystemic Shunt, Transjugular Intrahepatic / Q000009:adverse effects*; D012086:Reoperation / Q000009:adverse effects; D055502:Secondary Prevention; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D007496:Iridium Radioisotopes