Prasan Patel BSC, Presenter: Dr. Stephanie R. Wilson Consultant: Lantheus Medical Imaging Research Grants: AbbVie Pharma, Janssen Inc., and Lantheus Equipment Support: Philips, and Siemens Dr. Kerri L. Novak Research Grants: AbbVie Pharma and Janssen Inc.

Aman Wadhwani BSC, Abstract Co-Author: Nothing to Disclose

Alexandra Wilson BSC, Abstract Co-Author: Nothing to Disclose

Kerri Novak MD, Abstract Co-Author: Research Grant, Abbott Laboratories Consultant, Abbott Laboratories Speakers Bureau, Merck KgaA

Stephanie R. Wilson MD, Abstract Co-Author: Research Grant, AbbVie Inc Grant, Johnson & Johnson Consultant, Lantheus Medical Imaging, Inc Equipment support, Siemens AG Equipment support, Koninklijke Philips NV

To assess the utility of ultrasound (US) in determining therapeutic response to Infliximab induction therapy in Crohn disease (CD) patients.

This retrospective, single-centre review comprises 55 patients with established CD given infliximab as induction therapy and then monitored sonographically and clinically. All patients had baseline US scans with colour Doppler (CD) prior to Infliximab initiation, with subsequent interval US scans between 3 and 48 months (range of 3-5 scans). All US scans were classified as showing mild/moderate/severe inflammation or remission, on the basis of wall thickness, hyperemia, and mesenteric inflammatory fat. Complications were documented. Sonographic responsiveness following infliximab induction was defined as a decrease in wall thickness (to <4mm), inflammatory fat and CD signal. In this retrospective review, gold standard gross pathology was available in 10 patients. Multiple endoscopic evaluations were not consistently timed in this retrospective review.

Ultrasound showed an excellent ability to detect response to infliximab, favourable at 3 months in 40/55 (78%) patients, increasing to 45/55 (82%) by 24 months. Two patients showed partial sonographic responsiveness, with a minimal decrease in wall thickness, inflammatory fat and CD signal, and 8 patients showed severe inflammation with a lack of response on interval US, in spite of reduction of symptoms on therapy. All 10 of these patients, with maximum disease activity in the terminal ileum and jejunum, had surgical resection between 12-48 months post-induction, confirming active inflammation in all and stricture in 4, with complete agreement between pathology and US for assessment of disease activity and complications. All 10 post-surgical patients re-initiated infliximab therapy with no identified recurrent disease in 12-24 months of follow up.

US performed with CD allows for non-invasive and accurate prediction of responsiveness to infliximab, evident as early as 3 months following induction.

Infliximab induction therapy for CD can be monitored safely and accurately using US, potentially allowing us to predict those requiring dose escalation, additional therapy or surgical intervention.

Patel, P, Wadhwani, A, Wilson, A, Novak, K, Wilson, S, Monitoring Response to Infliximab Induction Therapy in Crohn Disease with Interval Ultrasound: A Safe and Effective Option.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14002556.html