A proton imaging system using a volumetric liquid scintillator: a preliminary study.

Area of Science:

• Medical Physics
• Radiotherapy Imaging
• Particle Therapy

Background:

• Proton radiotherapy requires advanced imaging for precise treatment planning, alignment, and verification.
• Current proton imaging methods face challenges in acquisition time and imaging dose.

Purpose of the Study:

• To demonstrate the feasibility of a volumetric liquid scintillator system for proton radiography at 180 MeV.
• To evaluate the system's potential for reducing imaging dose and acquisition time.

Main Methods:

• A 20 cm³ volumetric organic liquid scintillator coupled with a CCD camera was used as a residual-range detector.
• Scintillation light intensity was converted to water-equivalent thickness (WET) using a calibrated curve.
• Proton CT images were reconstructed using filtered back-projection from radiographic projections.

Main Results:

• The system achieved a spatial resolution of 0.19 line-pairs/mm.
• Accurate WET values were obtained for phantom inserts (e.g., -0.82% for solid water, 0.91% for acrylic, -2.43% for cortical bone).
• Reconstructed proton CT WET values showed excellent agreement (within 0.3%) with Monte Carlo simulations.

Conclusions:

• A volumetric liquid scintillator detector is viable for cumulative proton imaging at clinically relevant energies.
• The developed system shows promise for improving accuracy and efficiency in proton therapy.
• This technology can potentially reduce imaging dose and acquisition time in proton radiography.