SU-E-T-244: High Spatial Resolution EBT2 Film Dosimetry.

Area of Science:

• Medical Physics
• Radiation Dosimetry

Background:

• Accurate measurement of radiation dose distribution is critical in radiotherapy.
• Conventional methods for measuring dose near high-Z interfaces have limitations in spatial resolution and quality.

Purpose of the Study:

• To develop and validate a new method for measuring depth dose curves and dose effects near high-Z interfaces.
• To achieve spatial resolution superior to conventional techniques using radiochromic EBT-2 films.

Main Methods:

• Utilized a setup with RW3 stacks and vertically positioned EBT-2 films irradiated with a 15MV photon beam.
• Measured depth dose curves with films parallel to beam propagation.
• Assessed dose enhancement near a dental gold alloy probe at 6cm depth.

Main Results:

• The new method demonstrated depth dose curve measurements with less than 3% deviation compared to conventional methods.
• Dose enhancement measurements near a gold probe showed within 5% consistency with Monte Carlo simulations.
• High spatial resolution was achieved, limited only by scanner resolution.

Conclusions:

• The introduced method offers significant advantages over conventional orthogonal EBT-2 film positioning.
• The technique provides very high spatial resolution for investigating dose profiles near interfaces and inhomogeneities.
• This method is suitable for future studies in radiation oncology and medical physics.