Exposure dose has been indicated by surface dose or transit dose, but they could not indicate dose distributions inside the body. Modulex as the radiation therapy planning system was used for dose distributions at standard diagnostic X-ray energy. X-ray is low energy X-ray at standard diagnostic radiography, so alterations of the energy and the scattering dose distribution by absorbers are quite different from those at high energy X-rays. Mix-DP was put to the homogeneous tissue use, then Bone equivalent phantom or Lung equivalent phanton was put to the inhomogeneous tissue use. Density correction factors for inhomogeneous phantoms were gotten by the calculation of the water equivalent thickness. In Bone the inhomogeneous correction depended strongly on the bone thickness. In Lung it was in need of one density correction factor and the scattering correction method for the decrease of the back scattering. The calculated dose distributions by Modulex agreed with measured data when each correction was carried out, and it was indicated that those data apply to inclinical situations.
Radiation Therapy Planning System