Development and refinement of a technique using a medical radiation therapy facility to irradiate immunodeficient mice bearing xenografted human tumours.

The need for using immunodeficient mice for xenoimplantation of tumours is increasing in translational research in radiation oncology. However, adverse effects of radiation and infectious diseases may ruin the experimental work, in particular when appropriate facilities are not available. In this report, we describe a procedure to deliver fractionated radiotherapy to xenoimplanted tumours in immunodeficient mice using a medical linear accelerator, a method that was devised as an alternative to the lack of facilities devoted to radiation research. The mice were irradiated under anaesthesia and aseptic conditions. Thirty Gray in 10 days using a 6 MV photon beam were delivered only to the right thigh of the mice where tumours were implanted. The mice were evaluated twice a week up to planned euthanasia. The follow-up of mice was completed without premature interruption due to toxicities or infectious diseases, an observation which demonstrates the feasibility of the method.