Comparison of pancreatic respiratory motion management with three abdominal corsets for particle radiation therapy: Case study. Issue 6 (23rd May 2019)

• Record Type: Journal Article
• Authors: Dolde, Kai; Schneider, Sergej; Stefanowicz, Sarah; Alimusaj, Merkur; Flügel, Beate; Saito, Nami; Troost, Esther G. C.; Pfaffenberger, Asja; Hoffmann, Aswin L.
• Is Part Of: Journal of applied clinical medical physics. Volume 20:Issue 6(2019)
• Page Start: 111
• Page End: 119
• Publication Date: 2019-05-23
• Subjects: 4D‐MRI -- abdominal corset -- image‐guided radiotherapy -- motion management -- pancreatic cancer -- particle therapy; Medical physics -- Periodicals; Clinical medicine -- Periodicals; Health Physics; Clinical Medicine; Electronic journals; Periodicals; Periodicals; Fulltext; Internet Resources; 610.153
• DOI: 10.1002/acm2.12613
• Languages: English
• ISSNs: 1526-9914

Abstract

Abstract: Background and purpose: Abdominal organ motion seriously compromises the targeting accuracy for particle therapy in patients with pancreatic adenocarcinoma. This study compares three different abdominal corsets regarding their ability to reduce pancreatic motion and their potential usability in particle therapy. Materials and methods: A patient‐individualized polyurethane (PU), a semi‐individualized polyethylene (PE), and a patient‐individualized three‐dimensional‐scan based polyethylene (3D‐PE) corset were manufactured for one healthy volunteer. Time‐resolved volumetric four‐dimensional‐magnetic resonance imaging (4D‐MRI) and single‐slice two‐dimensional (2D) cine‐MRI scans were acquired on two consecutive days to compare free‐breathing motion patterns with and without corsets. The corset material properties, such as thickness variance, material homogeneity in Hounsfield units (HU) on computed tomography (CT) scans, and manufacturing features were compared. The water equivalent ratio (WER) of corset material samples was measured using a multi‐layer ionization chamber for proton energies of 150 and 200 MeV. Results: All corsets reduced the pancreatic motion on average by 9.6 mm in inferior–superior and by 3.2 mm in anterior‐posterior direction. With corset, the breathing frequency was approximately doubled and the day‐to‐day motion variations were reduced. The WER measurements showed an average value of 0.993 and 0.956 for the PE and 3DPE corset, respectively, and of 0.298 for the PU corset. The PE and 3DPE corsets showed a constant thickness of 2.8 ± 0.2 and 3.8 ± 0.2 mm, respectively and a homogeneous material composition with a standard deviation (SD) of 31 and 32 HU, respectively. The PU corset showed a variable thickness of 4.2 − 25.6 mm and a heterogeneous structure with air inclusions with an SD of 113 HU. Conclusion: Abdominal corsets may be effective devices to reduce pancreatic motion. For particle therapy, PE‐based corsets are preferred over PU‐based corset due to their material homogeneity and constant thickness.