SU‐GG‐J‐170: Small Animal Conformal Radiation Therapy Device

Abstract

Purpose: To develop a Small Animal Conformal Radiation Therapy Device (SACTRD) that will provide a degree of geometric/anatomic targeting comparable to what is achievable in current clinical radiotherapy practice to promote translational research in radiation oncology. Method and Materials: The SACRTD will integrate 3D‐conformal radiation therapy delivery with cone beam CT (CBCT) imaging for image‐based treatment planning and guided‐delivery. The main system components are: A Seifert Isovolt Titan 225kV X‐ray tube with focal spot sizes of 0.4 and 3 mm, which is mounted on a custom made “gantry” and has a special collimating assembly that allows field sizes down to 0.5 mm diameter at the 34 cm isocenter. A second main component is a computer‐controlled robotic arm (Adept Viper S650) for animal positioning. The six degrees of freedom (6DOF) robot can be programmed to move with an accuracy ±0.020 mm in XYZ directions. A third main component is a digital X‐ray flat panel detector for CBCT. The X‐ray source, the flat panel imager and the robot will be integrated for radiation delivery and imaging. A shielded enclosure housing the SACRTD is presented in a companion abstract. The final system will be capable of precise, accurate and quantifiable conformal delivery of radiation dose to selected targets within small animals in single or multiple fractions. Results: The development of SACRTD is in progress and current work is focused on stable gantry design, characterization of the X‐ray beam at various energies and programming of the robotic animal positioning system. Conclusion: The development of the SACRTD in an academic laboratory is a feasible but challenging undertaking, which has been motivated by the need for a R&D tool for biological, functional and molecular studies in radiation oncology using small animals which can effectively mimic current and future clinical systems.