In this paper, the effect of additional adipose and muscle layers was investigated on theeffective dose and the organ absorbed dose. Calculations were performed using the MonteCarlo N-Particle Transport Code (MCNP) and the ORNL mathematical phantom for externalphoton and neutron beams. Variations in adipose and muscle tissue thickness were modeledby adding layers of adipose and soft tissues around the torso of the phantom. Theeffective dose decreased by about 7%–40% when the thickness of the extra layer increasedfrom 0.5 to 5 cm considering all photon energies (10 keV–10 MeV) and neutron energies(10–9–20 MeV) for anterior-posterior, posterior-anterior, left-lateral,right-lateral, rotation and isotropic irradiation geometries. The results calculated herewere compared with those reported in previous studies such as those of the VIPMAN,NORMAN05, MASH-3 and ICRP reference voxel phantoms. Our data shows that adding properadipose or muscle layers to two very different phantoms can cause similar effective dosevalues, and also more than half of the organ absorbed doses have satisfactoryagreement.
