Characterization of Clinac-18 electron-beam energy using a magnetic analysis method

Area of Science:

• Medical Physics
• Radiation Oncology
• Particle Accelerators

Background:

• Accurate electron beam dosimetry is critical for effective radiation therapy.
• Verification of linear accelerator (LINAC) output parameters ensures treatment precision.
• Standard range method is a common but indirect measure of electron beam energy.

Purpose of the Study:

• To validate the accuracy of electron beam energies from a Clinac-18 linear accelerator.
• To compare magnetic analysis with the standard range method for energy determination.
• To characterize the spectral energy distribution of the electron beam.

Main Methods:

• Magnetic analysis was employed to measure electron beam energies and spectral distributions.
• Results were compared against those obtained using the standard range method.
• Measurements were cross-referenced with nominal energies provided by the manufacturer.

Main Results:

• Electron beam energies measured by both methods agreed with manufacturer specifications to within +/- 0.6 MeV.
• The spectral energy distribution exhibited a full-width at half-maximum (FWHM) of approximately 1 MeV.
• This spectral width was consistent across all tested electron beam energies.

Conclusions:

• Magnetic analysis provides a reliable method for verifying Clinac-18 electron beam energies.
• Both methods confirm the manufacturer's specifications for electron beam output.
• Consistent spectral energy distribution is crucial for predictable dose deposition in radiotherapy.