Background: The purpose of this study was to investigate the application of the Monte Carlo technique to calculate and analysis of dosimetric parameters for electron beams used in radiotherapy. This technique is based on statistical method and has a powerful role in different radiotherapy aspects.
Materials and Methods: The simulated medical linear accelerator was the Varian Clinac 2100C. The electron beams 9, 12 and 20 MeV were simulated by MCNP4C Monte Carlo code. The beam geometry was 10 × 10 cm2 applicator, 100 cm SSD on the surface of homogenous water phantom. Central-axis percentage depth dose (PDD) curves and dose profile (off axis ratio) were obtained to compare with experimental measurements.
 Results: The comparisons between calculated and experimental results show good agreement (within ±3%).
Conclusions: The MCNP4C code is a powerful tool for acquiring electron dosimetry results as well as other applications in radiotherapy.