Abstract
Radiation therapy treatment planning based on Monte Carlo simulation provide a very accurate dose
calculation compared to deterministic systems. Moreover, metaloxidesemiconductor field effect transistor
(MOSFET) dosimeters are increasingly utilized in radiation therapy.
In the present work, we have used the MCNP5 (Monte Carlo N-Particle transport code) to simulate the
irradiation of an anthropomorphic phantom (RANDO) with a medical linear accelerator.
The detailed model of the Elekta Precise MultiLeaf Collimator using a 6 MeV photon beam was
designed and validated by means of different beam sizes and shapes in previous works.
This study includes in the simulation the RANDO phantom geometry. To that, a set of Computer
Tomography images of the phantom was obtained via Computer Tomography and formatted. The slices
are input in PLUNC software, which performs the segmentation by defining anatomical structures and
a Matlab algorithm writes the phantom information in MCNP5 input deck format.
The simulation has been verified and validated throughout the comparison of High-Sensitivity MOSFET
dosimeter (Best medical Canada) measurements in different points inside the phantom with simulation
results. On-line Wireless MOSFET provide dose estimation in the extremely thin sensitive volume,
so a meticulous and accurate validation has been performed.
The comparison show good agreement between the MOSFET measurements and the Monte Carlo
calculations, confirming the validity of the developed procedure to include patients CT
