Abstract
Variations in anatomical delineation, principally due to a combination of inter-observer contributions and image-specificity, remain one of the most significant impediments to geometrically-accurate radiotherapy. Quantification of spatial variability of the delineated contours comprising a structure can be made with a variety of metrics, and the availability of software tools to apply such metrics to data collected during inter-observer or repeat-imaging studies would allow their validation. A suite of such tools have been developed which use an Extensible Markup Language format for the exchange of delineated 3D structures with radiotherapy planning or review systems. These tools provide basic operations for manipulating and operating on individual structures and related structure sets, and for deriving statistics on spatial variations of contours that can be mapped onto the surface of a reference structure. Use of these tools on a sample dataset is demonstrated together with import and display of results in the SWAN treatment plan review system.
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Notes
See for example the Fellowship in Anatomic deLineation and CONtouring (FALCON) project of the European Society for Therapeutic Radiology and Oncology (ESTRO), http://www.estro-education.org/elearning/Pages/FALCON.aspx.
Note that the terms ‘contour/contouring’, ‘volume/voluming’, ‘delineation/delineating’ are frequently used interchangeably to describe definition of regions of interest on radiographic images, with the resulting regions of interest interchangeably called ‘contours’, ‘volumes’ and ‘structures’. Here we refer to ‘structures’ as the 3D object constituted by a series of individual 2D ‘contours’.
swan.wager.org.au/swanserv/hello.htm.
crl.med.harvard.edu/software/STAPLE/index.php.
VAST utilises the XML Toolkit developed by Dr Marc Molinari and accessible from http://www.geodise.org/.
Those interested in developing or using the tool for non-clinical applications should contact the corresponding author.
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Acknowledgments
This research received funding from Cancer Australia and the Diagnostics and Technology Branch of the Australian Government Department of Health and Ageing. We are grateful to Dr. Marc Molinari from GeodiseLab for assistance and for the provision of the XML toolbox for Matlab; John Geraghty for work preparing sample data; and Matthijs Breebaart for the initial formulation of the XML format.
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Ebert, M.A., McDermott, L.N., Haworth, A. et al. Tools to analyse and display variations in anatomical delineation. Australas Phys Eng Sci Med 35, 159–164 (2012). https://doi.org/10.1007/s13246-012-0136-2
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DOI: https://doi.org/10.1007/s13246-012-0136-2