An efficient and robust MRI-guided radiotherapy planning approach for targeting abdominal organs and tumours in the mouse

Introduction: Preclinical CT-guided radiotherapy platforms are increasingly used but the CT images are characterized by poor soft tissue contrast. The aim of this study was to develop a robust and accurate method of MRI-
Introduction: Preclinical CT-guided radiotherapy platforms are increasingly used but the CT images are characterized by poor soft tissue contrast. The aim of this study was to develop a robust and accurate method of MRI-guided radiotherapy (MR-IGRT) delivery to abdominal targets in the mouse.
Methods: A multimodality cradle was developed for providing subject immobilisation and its performance was evaluated. Whilst CT was still used for dose calculations, target identification was based on MRI. Each step of the radiotherapy planning procedure was validated initially in vitro using BANG gel dosimeters. Subsequently, MR-IGRT of normal adrenal glands with a size-matched collimated beam was performed. Additionally, the SK-N-SH neuroblastoma xenograft model and the transgenic KPC model of pancreatic ductal adenocarcinoma were used to demonstrate the applicability of our methods for the accurate delivery of radiation to CT-invisible abdominal tumours.
Results: The BANG gel phantoms demonstrated a targeting efficiency error of 0.56 ± 0.18 mm. The in vivo stability tests of body motion during MR-IGRT and the associated cradle transfer showed that the residual body movements are within this MR-IGRT targeting error. Accurate MR-IGRT of the normal adrenal glands with a size-matched collimated beam was confirmed by γH2AX staining. Regression in tumour volume was observed almost immediately post MR-IGRT in the neuroblastoma model, further demonstrating accuracy of x-ray delivery. Finally, MR-IGRT in the KPC model facilitated precise contouring and comparison of different treatment plans and radiotherapy dose distributions not only to the intra-abdominal tumour but also to the organs at risk.
Conclusion: This is, to our knowledge, the first study to demonstrate preclinical MR-IGRT in intra-abdominal organs. The proposed MR-IGRT method presents a state-of-the-art solution to enabling robust, accurate and efficient targeting of extracranial organs in the mouse and can operate with a sufficiently high throughput to allow fractionated treatments to be given.
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Metadaten
Author:Veerle Kersemans, John S. Beech, Stuart Gilchrist, Paul Kinchesh, Philip D. Allen, James Thompson, Ana L. Gomes, Zenobia D’Costa, Luke Bird, Iain D. C. Tullis, Robert G. Newman, Aurélien Corroyer-Dulmont, Nadia Falzone, Abul Azad, Katherine Vallis, Owen J. Sansom, Ruth J. Muschel, Borivoj Vojnovic, Mark A. Hill, Emmanouil Fokas, Sean C. Smart
URN:urn:nbn:de:hebis:30:3-440469
DOI:http://dx.doi.org/10.1371/journal.pone.0176693
ISSN:1932-6203
Pubmed Id:http://www.ncbi.nlm.nih.gov/pubmed?term=28453537
Parent Title (English):PLoS one
Publisher:PLoS
Place of publication:Lawrence, Kan.
Contributor(s):Qinghui Zhang
Document Type:Article
Language:English
Date of Publication (online):2017/05/08
Date of first Publication:2017/04/28
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2017/05/08
Volume:12
Issue:(4): e0176693
Pagenumber:21
First Page:1
Last Page:21
Note:
Copyright: © 2017 Kersemans et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
HeBIS PPN:415179777
Institutes:Medizin
Dewey Decimal Classification:610 Medizin und Gesundheit
Sammlungen:Universitätspublikationen
Licence (German):License LogoCreative Commons - Namensnennung 4.0

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