Challenges in evaluating the performance of the electron beam dose calculation algorithm: Monte Carlo simulation and Gamma index.

INTRODUCTION

The effectiveness of the Electron Monte Carlo Algorithm in ensuring accurate dose calculations in radiotherapy is still under investigation. While the Monte Carlo simulation has become a crucial tool for precise dosimetry in recent decades, its sufficiency when used alone is yet to be definitively established. This work aims to provide valuable insights into the relevance and reliability of the Electron Monte Carlo algorithm and the Monte Carlo simulation of electron beam in radiotherapy.

METHODS

Through a comprehensive analysis, we seek to elucidate the algorithm's role, highlight its strengths and limitations, and evaluate its impact on the accuracy of dose distribution predictions. Percentage depth dose curves were derived for a reference field size across a range of electron beam energies: 6, 9, 12, 16, and 20 MeV in the water phantom. These curves were compared with others obtained from Monte Carlo Simulation. Gamma index was employed to ensure rigorous validation of dose distributions and supports the maintenance of high standards in radiotherapy quality assurance.

RESULTS

The results demonstrate a high degree of concordance between the empirical dose percentages and those predicted by computational models across all examined energy levels, achieving a success rate exceeding 93.5 % at the 3 % dose difference and 3 mm distance-to-agreement criteria.

CONCLUSION

The results suggest that using of the Electron Monte Carlo algorithm may lead to an underestimation of the dose in the region of electron equilibrium, while simulations using Geant4 code seems to provide more accurate results and is closer to the experimental data.

IMPLICATIONS FOR PRACTICE

These results underscore the efficacy of Monte Carlo simulations in enhancing the precision of treatment planning and delivery, thereby advancing their application in clinical radiotherapy settings.