Reduction of intrafraction pancreas motion using an abdominal corset compatible with proton therapy and MRI.

Abstract

Background and purpose:

Motion mitigation is of crucial importance in particle therapy (PT) of patients with abdominal tumors to ensure high-precision irradiation. Magnetic resonance imaging (MRI) is an excellent modality for target volume delineation and motion estimation of mobile soft-tissue tumors. Thus, the aims of this study were to develop an MRI- and PT-compatible abdominal compression device, to investigate its effect on pancreas motion reduction, and to evaluate patient tolerability and acceptance.

Materials and methods:

In a prospective clinical study, 16 patients with abdominal tumors received an individualized polyethylene-based abdominal corset. Pancreas motion was analyzed using time- and phase resolved MRI scans (orthogonal 2D-cine and 4D MRI) with and without compression by the corset. The pancreas was manually segmented in each MRI data set and the population-averaged center-of-mass motion in inferior-superior (IS), anterior-posterior (AP) and left-right (LR) directions was determined. A questionnaire was developed to investigate the level of patient acceptance of the corset, which the patients completed after acquisition of the planning computed tomography (CT) and MRI scans.

Results:

The corset was found to reduce pancreas motion predominantly in IS direction by on average 47 % - 51 % as found in the 2D-cine and 4D MRI data, respectively, while motion in the AP and LR direction was not significantly reduced. Most patients reported no discomfort when wearing the corset.

Conclusion:

An MRI- and PT-compatible individualized abdominal corset was presented, which substantially reduced breathing-induced pancreas motion and can be safely applied with no additional discomfort for the patients. The corset has been successfully integrated into our in-house clinical workflow for PT of tumors of the upper abdomen.

• Authors: Sergej Schneider, Sarah Stefanowicz, Christina Jentsch, Fabian Lohaus, Julia Thiele, Danilo Haak, Chiara Valentini, Ivan Platzek, Esther G C Troost, Aswin L Hoffmann
• Journal: Clinical and translational radiation oncology (Clin Transl Radiat Oncol) Vol. 38 Pg. 111-116 (Jan 2023) ISSN: 2405-6308 [Electronic] Ireland
• PMID: 36407488 (Publication Type: Journal Article)
• Copyright: © 2022 The Author(s).