Anatomical Deformation Due to Horizontal Rotation: Towards Gantry-Free Radiation Therapy
Field | Value | Language |
dc.contributor.author | Buckley, J | |
dc.contributor.author | Rai, R | |
dc.contributor.author | Liney, G | |
dc.contributor.author | Dowling, J | |
dc.contributor.author | Holloway, L | |
dc.contributor.author | Metcalfe, P | |
dc.contributor.author | Keall, P | |
dc.date.accessioned | 2020-07-10 | |
dc.date.available | 2020-07-10 | |
dc.date.issued | 2019-01-01 | en_AU |
dc.identifier.uri | https://hdl.handle.net/2123/22839 | |
dc.description.abstract | Gantry-free radiation therapy systems may be simpler and more cost effective, particularly for MRI-guided photon or hadron therapy. This study aims to understand and quantify anatomical deformations caused by horizontal rotation with scan sequences sufficiently short to facilitate integration into an MRI-guided workflow. Rigid and non-rigid pelvic deformations due to horizontal rotation were quantified for a cohort of 8 healthy volunteers using a bespoke patient rotation system and a clinical MRI scanner. For each volunteer a reference scan was acquired at 0° followed by sequential faster scans in 45° increments through to 360°. All fast scans were registered to the 0° image via a three-step process: first, images were aligned using MR visible couch markers. Second, the scans were pre-processed then rigidly registered to the 0° image. Third, the rigidly registered scans were non-rigidly registered to the 0° image to assess soft tissue deformation. The residual differences after rigid and non-rigid registration were determined from the transformation matrix and the deformation vector field, respectively. The rigid registration yielded mean rotations of ⩽2.5° in all cases. The average 3D translational magnitudes range was 5.8 ± 2.9 mm-30.0 ± 11.0 mm. Translations were most significant in the left-right (LR) direction. Smaller translations were observed in the anterior-posterior (AP) and superior-inferior (SI) directions. The maximum deformation magnitudes range was: 10.0 ± 0.9 mm-28.0 ± 2.8 mm and average deformation magnitudes range: 2.3 ± 0.6 mm-7.5 ± 1.0 mm. Average non-rigid deformation magnitude was correlated with BMI (correlation coefficient 0.84, p = 0.01). Rigid pelvic deformations were most significant in the LR direction but could be accounted for with on-line adjustments. Non-rigid deformations can be significant and will need to be accounted for in order to facilitate the delivery of gantry-free therapy with an automated patient rotation system. | en_AU |
dc.language.iso | en | en_AU |
dc.publisher | IOP Science | en_AU |
dc.relation.ispartof | Physics in Medicine & Biology | en_AU |
dc.rights | CC BY-NC-ND 4.0 | en_AU |
dc.subject | patient rotation | en_AU |
dc.subject | fixed gantry | en_AU |
dc.title | Anatomical Deformation Due to Horizontal Rotation: Towards Gantry-Free Radiation Therapy | en_AU |
dc.type | Article | en_AU |
dc.subject.asrc | 0299 Other Physical Sciences | en_AU |
dc.identifier.doi | 10.1088/1361-6560/ab324c | |
dc.relation.nhmrc | 1112096 | |
dc.relation.nhmrc | 1132471 | |
dc.rights.other | CC BY-NC-ND 4.0 | en_AU |
usyd.faculty | Faculty of Medicine & Health / Central Clinical School | en_AU |
usyd.department | ACRF Image X Institute | en_AU |
usyd.citation.volume | 64 | en_AU |
usyd.citation.issue | 17 | en_AU |
usyd.citation.spage | 175014 | en_AU |
workflow.metadata.only | No | en_AU |
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