Optimization of solid tank design for fan-beam optical CT based 3D radiation dosimetry

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Optical Imaging

Background:

• Optical computed tomography (CT) is crucial for 3D radiation dosimetry using gel dosimeters.
• Existing optical CT scanner designs face challenges in setup and maintenance due to large refractive index bath requirements.
• A standardized optical CT scanner for gel dosimetry is lacking.

Purpose of the Study:

• To propose and optimize a novel solid 'tank' optical CT scanner prototype.
• To minimize the refractive index bath volume required for optical CT gel dosimetry.
• To enhance scanner design for improved light collection and signal dynamic range.

Main Methods:

• Development of a prototype solid tank optical CT scanner.
• Creation of a ray-path simulator to optimize scanner geometry.
• Optimization of design parameters including block length, bore position, and laser position using an objective function.
• Simulation of scanner performance with specific dosimeter types (FlexyDos3D, ClearView™).

Main Results:

• The solid tank design drastically reduces refractive index bath volume to 10-35 ml.
• Optimized design parameters were identified for FlexyDos3D and ClearView™ dosimeters.
• Simulations demonstrated significant effects of design parameters on signal collection efficacy.
• The ray simulator proved effective for optimizing optical CT geometries.

Conclusions:

• The proposed solid tank optical CT scanner offers a more practical and efficient solution for 3D radiation dosimetry.
• The ray simulation tool is valuable for designing and testing new optical CT scanner geometries.
• This work addresses key limitations of current optical CT systems for gel dosimetry.