# Incorporating Clinical Imaging into the Delivery of Microbeam Radiation Therapy
## 4 Conclusions  
In this study, a method for small animal imaging and targeting was implemented at the Australian Synchrotron's Imaging and Medical Beamline, demonstrating the convenience of tools available to users on the beamline. The image guidance protocol for MRT treatment delivery is the first to use CT imaging for patient-specific tumour identification and co-registration with planar X-ray imaging for alignment. The advantage of such an approach is high precision in identifying features not discernible in planar X-ray images or optical cameras. Phantom measurements show the dose associated with the imaging process is acceptably low as to not affect outcomes, with CT surface dose of \((1.39\pm 0.08)\) cGy and planar X-ray image dose of \((0.028\pm 0.004)\) cGy. This study confirmed that sufficient tools are already in place within MRT treatment Hutch 2B of the Australian Synchrotron's Imaging and Medical Beamline to allow patient-specific tumour targeting with sub-millimetre precision (\(<\)\(\pm\)0.34 mm) in the implementation of simple treatment plans as verified with phantom and in vivo microbeam radiation therapy. To date, 35 tumour-bearing rats have been treated using this technique. Figure 10: Composite image with a histology slide overlaid on corresponding coronal CT slice of tumour-bearing rat, 14 days after MRT treatment (**left**). The enlarged image (**right**) shows a tumour situated within the MRT treatment field (parallel vertical lines) with microbeams present and expected numbered with red text identifying the microbeams that transit the tumour mass (dark circular object at the centre of the frame). The yellow shaded region highlights a void in the brain material caused by manual handling of the fragile tissue. **Author Contributions:** Conceptualization, J.P., M.B. and M.L. ; methodology, J.P., M.B., E.E., J.D., M.T., S.C. and M.L. ; software, J.P. and M.B. ; validation, J.P., M.B., E.E., J.D. and M.L. ; formal analysis, J.P.; investigation, J.P., M.B., E.E., J.D., M.d.V., M.T., M.L. ; resources, M.d.V. ; data curation, J.P.; writing--original draft preparation, J.P.; writing--review and editing, J.P., M.B., M.T., S.C., A.R., M.L., S.G.; supervision, M.L., S.G., S.C., M.T., M.d.V. and A.R. ; project administration, M.d.V., C.H. and D.H., M.L. ; funding acquisition, J.P., J.D., C.H., D.H., M.T., A.R. and M.L. All authors have read and agreed to the published version of the manuscript. **Funding:** This research received no external funding. **Institutional Review Board Statement:** All animal procedures were performed within the guidelines of the National Health and Medical Research Council (2013) Australian code for the care and use of animals for scientific purposes and under the approval of the University of Wollongong and Australian Synchrotron animal ethics committees (AE17/05 and AS-2017-001). **Informed Consent Statement:** Not applicable. **Data Availability Statement:** The authors confirm that the data supporting the findings of this study are available within the article. **Acknowledgments:** This research was supported by an Australian Government Research Training Program Scholarship and the Australian National Health & Medical Research Council (APP104994 and APP1093256). This research was undertaken on the Imaging and Medical beamline at the Australian Synchrotron, part of ANSTO (IMBL/13777;14127;15023) The authors acknowledge the facilities and scientific and technical assistance of the National Imaging Facility (NIF), a National Collaborative Research Infrastructure Strategy (NCRIS) capability at Monash Biomedical Imaging (MBI), a Technology Research Platform at Monash University; the Illawarra Health and Medical Research Institute (IHMRR), Wollongong, Australia; the Australian Synchrotron, Melbourne, Australia; the Australian Nuclear Science and Technology Organisation; and the University of Wollongong (UOW) Animal House.