title: 3D-Printed Small-Animal Immobilizer for Use in Preclinical Radiotherapy.
abstract: We have designed a method for immobilizing the subjects of small-animal studies using a study group-specific 3D-printed immobilizer that significantly reduces interfraction rotational variation. A cone-beam CT scan acquired from a single specimen in a study group was used to create a 3D-printed immobilizer that can be used for all specimens in the same study group. 3D printing allows for the incorporation of study-specific features into the immobilizer design, including geometries suitable for use in MR and CT scanners, holders for fiducial markers, and anesthesia nose cones of various sizes. Using metrics of rotational setup variations, we compared the current setup in our small-animal irradiation system, a half-pipe bed, with the 3D-printed device. We also assessed translational displacement within the immobilizer. The printed design significantly reduced setup variation, with average reductions in rotational displacement of 76% ± 3% (1.57 to 0.37°) in pitch, 78% ± 3% (1.85 to 0.41°) in yaw, and 87% ± 3% (5.39 to 0.70°) in roll. Translational displacement within the printed immobilizer was less than 1.5 ± 0.3 mm. This method of immobilization allows for repeatable setup when using MR or CT scans for the purpose of radiotherapy, streamlines the workflow, and places little burden on the study subjects.
authors.affiliation: Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA; The Graduate School of Biomedical Sciences, The University of Texas Health Science Center, Houston, Texas. REMcCarroll@mdanderson.org.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: McCarroll
authors.affiliation: Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA; The Graduate School of Biomedical Sciences, The University of Texas Health Science Center, Houston, Texas, USA.
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Rubinstein
authors.affiliation: Department of Imaging Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Charles V
authors.initials: CV
authors.lastname: Kingsley
authors.affiliation: Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Jinzhong
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of General Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Peiying
authors.initials: P
authors.lastname: Yang
authors.affiliation: Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Laurence E
authors.initials: LE
authors.lastname: Court
mesh_terms: D000818:Animals; D054893:Cone-Beam Computed Tomography; D007103:Immobilization / Q000295:instrumentation / Q000662:veterinary*; D008279:Magnetic Resonance Imaging; D051379:Mice; D066330:Printing, Three-Dimensional; D011878:Radiotherapy / Q000379:methods; D014057:Tomography, X-Ray Computed