Key people: Prof Peter Rogers, Dr Jeff Crosbie, Dr Jacqueline Donoghue
Currently, up to 50 per cent of cancer patients receive radiotherapy and although effective there are some significant limitations to treatment including damage to normal tissue. Due to targeting a tumor with a broad beam X-ray, the radiation dose administered must be delivered over several days to give the normal tissue time to recover. Synchrotron Microbeam Radiation Therapy (MRT) is a radiotherapy technique that treats tumors with narrow wafers of very high doses of synchrotron radiation and is delivered in very short amounts of time. These wafers result in peaks and valleys of radiation where the dose differential could be several 100 gray (Gy). Using the Imaging and Medical Beam Line (IMBL) at the Australian Synchrotron, we have developed several models to evaluate the X-rays generated by the synchrotron for novel, preclinical radiotherapy studies. Recently, we have characterised the response of established tumors, cell lines and normal tissue to MRT in comparison with conventional broad beam and synchrotron-broad beam radiation. Interestingly, normal tissue can tolerate X-ray doses 100 times greater than conventional radiotherapy when delivered by MRT.
We are currently investigating the mechanisms of normal tissue tolerance to MRT and how tumors are destroyed by MRT when only a tenth of tumor volume is irradiated at the peak MRT dose.