title: MR and CT imaging characteristics and ablation zone volumetry of locally advanced pancreatic cancer treated with irreversible electroporation.
abstract: OBJECTIVE
  To assess specific imaging characteristics after irreversible electroporation (IRE) for locally advanced pancreatic carcinoma (LAPC) with contrast-enhanced (ce)MRI and ceCT, and to explore the correlation of these characteristics with the development of recurrence.
  
  
  METHODS
  Qualitative and quantitative analyses of imaging data were performed on 25 patients treated with percutaneous IRE for LAPC. Imaging characteristics of the ablation zone on ceCT and ceMRI were assessed over a 6-month follow-up period. Contrast ratio scores between pre- and post-treatment were compared. To detect early imaging markers for treatment failure, attenuation characteristics at 6 weeks were linked to the area of recurrence within 6 months.
  
  
  RESULTS
  Post-IRE, diffusion-weighted imaging (DWI)-b800 signal intensities decreased in all cases (p < 0.05). Both ceMRI and ceCT revealed absent or decreased contrast enhancement, with a hyperintense rim on ceMRI. Ablation zone volume increase was noted on both modalities in the first 6 weeks, followed by a decrease (p < 0.05). In the patients developing tumour recurrence (5/25), a focal DWI-b800 hyperintense spot at 6 weeks predated unequivocal recurrence on CT.
  
  
  CONCLUSIONS
  The most remarkable signal alterations after pancreatic IRE were shown by DWI-b800 and ceMRI. These early imaging characteristics may be useful to establish technical success and predict treatment outcome.
  
  
  CONCLUSIONS
  • This study describes imaging characteristics after irreversible electroporation (IRE) for pancreatic adenocarcinoma. • Familiarity with typical post-IRE imaging characteristics helps to interpret ablation zones. • Post-IRE, no central and variable rim enhancement are visible on contrast-enhanced imaging. • DWI-b800 may prove useful to predict early tumour recurrence. • Post-IRE examinations reveal an initial volume increase followed by a decrease.
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands. la.vroomen@vumc.nl.
authors.forename: Laurien G P H
authors.initials: LGPH
authors.lastname: Vroomen
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Hester J
authors.initials: HJ
authors.lastname: Scheffer
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Marleen C A M
authors.initials: MCAM
authors.lastname: Melenhorst
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Marcus C
authors.initials: MC
authors.lastname: de Jong
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Janneke E
authors.initials: JE
authors.lastname: van den Bergh
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Cornelis
authors.initials: C
authors.lastname: van Kuijk
authors.affiliation: Department of Gastroenterology and Hepatology, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Foke
authors.initials: F
authors.lastname: van Delft
authors.affiliation: Department of Surgery, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Geert
authors.initials: G
authors.lastname: Kazemier
authors.affiliation: Department of Radiology and Nuclear Medicine, VU University Medical Center, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Martijn R
authors.initials: MR
authors.lastname: Meijerink
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D018274:Electroporation / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009364:Neoplasm Recurrence, Local; D010190:Pancreatic Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
keywords: Ablation; Computed tomography; Magnetic resonance imaging; Pancreatic neoplasms; Tumour volume