(Sunday, 7/14/2019) 4:00 PM - 5:00 PM
Room: Exhibit Hall | Forum 3
Purpose: Small animal x-ray irradiation platforms are expanding future pathways for radiobiology research. Meanwhile, as clinical proton radiotherapy is expanding, there is a lack of small animal radiobiology utilizing protons. A small animal radiotherapy platform incorporated with an existing clinical proton beam line was commissioned for use with in vivo experiments. Quality assurance (QA) protocols were developed to ensure reproducibility and accurate dosimetry for each experimental set-up.
Methods: A commercially available 225 kV x-ray small animal radiation research platform with imaging capabilities was installed on rails to align with a modified proton experimental beamline from a 230 MeV cyclotron-based clinical system. Collimated spread out Bragg peaks (SOBP) were produced with beams compatible for use in small animal models. Proton beam parameters were measured using film, ion chamber array, and Bragg peak chamber in water and characterized to establish baseline values to be used for quality control. A custom QA phantom and protocol was developed to ensure consistent alignment between the x-ray and proton beam isocenters as well as beam quality verification.
Results: The clinical proton beam line was commissioned to deliver Bragg peaks with range 4-30 mm in water with dose rates of 2 Gy/min. Alignment between the x-ray system and proton beam line agreed to within 0.5 mm and QA protocol-based shifts were <3 mm. Preliminary studies verify delivery of an SOBP in a murine tumor model.
Conclusion: An image-guided small animal x-ray and proton radiation research system was developed to enable in vivo studies of radiobiological effects of proton beams and allows for comparative studies between proton and photon beams. Initial commissioning and QA experience shows reproducible beam characteristics.
Keywords
Radiobiology, Quality Assurance, Protons
Taxonomy
Not Applicable / None Entered.
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