Accuracy and precision of patient positioning for pelvic MR-only radiation therapy using digitally reconstructed radiographs

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorKemppainen, R.
dc.contributor.authorVaara, T.
dc.contributor.authorJoensuu, T.
dc.contributor.authorKiljunen, T.
dc.contributor.departmentSchool services,SCI
dc.contributor.departmentPhilips MR Therapy
dc.contributor.departmentDocrates Cancer Center
dc.contributor.departmentDepartment of Neuroscience and Biomedical Engineeringen
dc.date.accessioned2020-03-13T15:25:27Z
dc.date.available2020-03-13T15:25:27Z
dc.date.issued2018-03-02
dc.description.abstractBackground and Purpose. Magnetic resonance imaging (MRI) has in recent years emerged as an imaging modality to drive precise contouring of targets and organs at risk in external beam radiation therapy. Moreover, recent advances in MRI enable treatment of cancer without computed tomography (CT) simulation. A commercially available MR-only solution, MRCAT, offers a single-modality approach that provides density information for dose calculation and generation of positioning reference images. We evaluated the accuracy of patient positioning based on MRCAT digitally reconstructed radiographs (DRRs) by comparing to standard CT based workflow. Materials and Methods. Twenty consecutive prostate cancer patients being treated with external beam radiation therapy were included in the study. DRRs were generated for each patient based on the planning CT and MRCAT. The accuracy assessment was performed by manually registering the DRR images to planar kV setup images using bony landmarks. A Bayesian linear mixed effects model was used to separate systematic and random components (inter- and intra-observer variation) in the assessment. In addition, method agreement was assessed using a Bland-Altman analysis. Results. The systematic difference between MRCAT and CT based patient positioning, averaged over the study population, were found to be (mean [95% CI]) -0.49 [-0.85 to -0.13] mm, 0.11 [-0.33 to +0.57] mm and -0.05 [-0.23 to +0.36] mm in vertical, longitudinal and lateral directions, respectively. The increases in total random uncertainty were estimated to be below 0.5 mm for all directions, when using MR-only workflow instead of CT. Conclusions. The MRCAT pseudo-CT method provides clinically acceptable accuracy and precision for patient positioning for pelvic radiation therapy based on planar DRR images. Furthermore, due to the reduction of geometric uncertainty, compared to dual-modality workflow, the approach is likely to improve the total geometric accuracy of pelvic radiation therapy.en
dc.description.versionPeer revieweden
dc.format.extent1-10
dc.format.mimetypeapplication/pdf
dc.identifier.citationKemppainen , R , Vaara , T , Joensuu , T & Kiljunen , T 2018 , ' Accuracy and precision of patient positioning for pelvic MR-only radiation therapy using digitally reconstructed radiographs ' , Physics in Medicine and Biology , vol. 63 , no. 5 , 055009 , pp. 1-10 . https://doi.org/10.1088/1361-6560/aaad21en
dc.identifier.doi10.1088/1361-6560/aaad21
dc.identifier.issn0031-9155
dc.identifier.issn1361-6560
dc.identifier.otherPURE UUID: b23903b1-89d9-41d4-99fb-9e3acdbbd81c
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/b23903b1-89d9-41d4-99fb-9e3acdbbd81c
dc.identifier.otherPURE LINK: http://www.scopus.com/inward/record.url?scp=85043484811&partnerID=8YFLogxK
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/41493246/SCI_Kemppainen_Accuracy.pub2_author_submitted_manuscript.pdf
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/43456
dc.identifier.urnURN:NBN:fi:aalto-202003132497
dc.language.isoenen
dc.publisherIOP Publishing Ltd.
dc.relation.ispartofseriesPhysics in Medicine and Biologyen
dc.relation.ispartofseriesVolume 63, issue 5en
dc.rightsopenAccessen
dc.subject.keyworddigitally reconstructed radioraphs
dc.subject.keywordimage-guided radiotherapy
dc.subject.keywordMRI-based radiotherapy
dc.subject.keywordradiotherapy
dc.titleAccuracy and precision of patient positioning for pelvic MR-only radiation therapy using digitally reconstructed radiographsen
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionacceptedVersion
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