Measurement-based validation of a commercial Monte Carlo dose calculation algorithm for electron beams

Area of Science:

• Medical Physics
• Radiation Oncology
• Computational Dosimetry

Background:

• Accurate dose calculation is crucial for effective radiation therapy planning.
• Monte Carlo (MC) methods offer high accuracy in dose prediction.
• Clinical validation of MC codes ensures their reliability in treatment planning.

Purpose of the Study:

• To clinically validate RayStation's electron Monte Carlo (MC) code.
• To assess the code's accuracy in homogeneous and heterogeneous tissues.
• To compare results against internationally accepted dosimetry criteria.

Main Methods:

• Validation performed using diodes and parallel radiation detectors on an Elekta linac (4-12 MeV).
• Evaluated various treatment setups including oblique incidences and heterogeneous inserts (lung, air, bone).
• Adhered to Netherlands Commission for Radiation Dosimetry (NCS) report 15 criteria for dose agreement and distance-to-agreement (DTA).

Main Results:

• RayStation's electron MC code met NCS report 15 tolerances.
• Dose prediction accuracy improved with energy and applicator size; no dependence on field size or energy for cutouts.
• Excellent agreement for oblique incidences and minimal DTA difference behind heterogeneous inserts were observed.

Conclusions:

• RayStation's MC-based electron dose prediction is accurate for Elekta accelerators.
• The code provides clinically acceptable accuracy within a practical timeframe.
• Validated for both homogeneous and heterogeneous media in clinical treatment planning.