Journal Article

MR and CT imaging characteristics and ablation zone volumetry of locally advanced pancreatic cancer treated with irreversible electroporation

Vroomen, Laurien G. P. H., Melenhorst, Marleen C. A. M., van den Bergh, Janneke E., van Kuijk, Cornelis, Meijerink, Martijn R., Scheffer, Hester J., Kazemier, Geert, van Delft, Foke, de Jong, Marcus C.

2017

Overview

Objectives 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. Conclusion 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. Key Points • 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.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V
• Subject: Adenocarcinoma - pathology / Adult / Aged / Diagnostic Radiology / Diffusion Magnetic Resonance Imaging / Electroporation - methods / Female / Humans / Imaging / Internal Medicine / Interventional Radiology / Magnetic Resonance Imaging - methods / Male / Medicine / Medicine & Public Health / Middle Aged / Multimodal Imaging - methods / Neoplasm Recurrence, Local / Neuroradiology / Oncology / Pancreatic cancer / Pancreatic Neoplasms / Pancreatic Neoplasms - pathology / Radiology / Tomography, X-Ray Computed - methods / Treatment Outcome / Ultrasound