Abstract
It has been demonstrated that radiation effects of 25μm thick deuterium rays on mouse brain are much less toxic than those of 1mm thick rays, which was found when they studied it for the purpose to find the biological effects of cosmic rays in 1950s. Slatkin et al extended this finding to the study of the effects of microplanar synchrotron radiation collimated at 20μm width and 200μm center-to-center beam distance on rat brain and found that no change was observed at the in-beam skin dose of 625Gy [Proc. Natl. Acad. Sci. USA 92, 8783 (1995)]. This irradiation modality with a slight modification (25μm width and 100μm center-to-center beam distance) was applied to rat 9L gliosarcoma and gave a good results of prolonged life span with better results at the irradiation mode of orthogonally crossed arrays [Laissue et al, Int. J. Cancer 78, 654 (1998)].
This irradiation method for radiation therapy is a proposal for a new treatment modality using characteristic advantages of synchrotron radiation, i.e., low beam divergence and extremely high photon flux. The mechanism is not clear but the finding is worth to be studied biologically. In this talk we will introduce a quick review of the reported works.
