Abstract
Micro-planar beam radiation therapy has been developed with synchrotron radiation. The method is single irradiation of one direction or orthogonal two directions at high dose up to 600 Gy using an array of narrow planar beam (width of about 20-50μm) with the center-to-center distance of about 10 times of the beam width, resulting in an increase in life span of tumor baring animals with high recovery ratio of normal tissue. The energy of X-rays for the animal study has been reported below 300 keV with synchrotron radiation.
In the present study, beam profiles at high energy up to 1 MeV was calculated by Monte Carlo simulation with the code system of PENELOPE-2008*. The model arrangement of the system was as follows: Thickness of 10cm collimator made of tungsten having 5 slits of 20μm beam width and 200μm center-to-center distance, air layer of 1mm, and water phantom of 20cm. Beam profiles were obtained for the relative absorbed dose in 1cm depth at 10cm to 11cm in water. The results show that peak-to-valley ratio of 100 keV, 200 keV, 500 keV and 1 MeV were 150, 332, 2.37 and 1.62, respectively. Possibility of micro-planar beam radiation therapy at high energy will be discussed.
*F. Salvat, J.M. Fernández-Verea and J. Sempau, "PENELOPE-2008: A Code System for Monte Carlo Simulation of Electron and Photon Transport" (OECD Nuclear Energy Agency, ISSY-les-Moulineaux, France, 2008).
