Optical scanner for 3D radiotherapy polymer gel dosimetry

Area of Science:

• Medical Physics
• Radiotherapy Dosimetry
• Polymer Science

Background:

• Radiotherapy requires precise 3D dosimetry for accurate tumor irradiation and treatment verification.
• Polymer gel dosimetry offers high-resolution 3D absorbed dose distribution measurements.
• Current analysis of polymer gel dosimeters primarily relies on Magnetic Resonance Imaging (MRI).

Purpose of the Study:

• To develop and evaluate an optical computed tomography scanner as an alternative to MRI for polymer gel dosimetry.
• To assess the feasibility of optical scanning for precise 3D radiation dose distribution measurements.
• To present initial results from a novel optical scanner using a PABIGnx polymer gel dosimeter.

Main Methods:

• Construction of an optical scanner utilizing a laser diode, scanning system, and signal detector.
• Measurement of a 3D polymer gel dosimeter immersed in a liquid to minimize light deflection.
• Irradiation of the polymer gel dosimeter with an 192Ir brachytherapy source for inhomogeneous dose distribution.
• Comparison of results obtained from the optical scanner with those from MRI.

Main Results:

• The newly constructed optical scanner successfully measured dose distributions in a PABIGnx polymer gel dosimeter.
• Initial results demonstrated the capability of the optical scanner to capture inhomogeneous dose distributions.
• Performance was contrasted with established MRI-based dosimetry.

Conclusions:

• The developed optical scanner shows promise as a viable and potentially more accessible method for 3D polymer gel dosimetry.
• Further optimization of the optical scanner is ongoing to enhance its performance and accuracy.
• This technique could provide a valuable tool for radiotherapy treatment planning and verification.