Calculation of fluence to dose conversion coefficients in partial exposure

Organ doses and effective doses of electrons and photons for the partial exposure using the MIRD-5 phantom and EGS-4 Code have been calculated. Irradiation geometries are AP and PA exposure. Calculations are carried out using 5 isocentered beams with different sizes to investigate the beam sizes effect on the effective dose. The results show that the effective doses depend not only on the energy of incident particle but also on the exposure position and the beam size on the body.