A novel proton-integrating radiography system design using a monolithic scintillator detector: experimental studies

Area of Science:

• Medical Physics
• Radiotherapy Technology
• Imaging Systems

Background:

• Proton radiotherapy requires precise treatment planning and patient alignment.
• Current proton radiography systems using thin scintillating plates have limitations.
• Novel imaging systems are needed to enhance visualization of internal anatomy.

Purpose of the Study:

• To demonstrate a new proton radiography system design using a monolithic plastic scintillator and two optical cameras.
• To evaluate the system's performance for proton radiotherapy applications.
• To compare two methods of generating proton radiographs for improved accuracy.

Main Methods:

• A monolithic plastic scintillator (20 × 20 × 20 cm³) and two optical cameras were used.
• Proton radiographs were generated by integrating light along the beam axis and capturing Bragg peak shifts perpendicular to the beam axis.
• A curvelet minimization algorithm processed percentage depth light (PDL) profiles to reconstruct water-equivalent thickness (WET) maps.

Main Results:

• The proton imaging system demonstrated excellent uniformity (2.6%), stability (0.37%), and linearity (R² = 1).
• Accurate WET calculations were achieved for various phantom materials (solid water, adipose, cortical bone, PMMA) using both imaging methods.
• The perpendicular camera method showed relative WET accuracies ranging from -0.15 ± 2.64% to 0.36 ± 3.93%.

Conclusions:

• The novel multicamera proton radiography system shows significant potential for clinical applications in proton radiotherapy.
• The system's ability to accurately map WET can improve treatment planning and patient alignment.
• Further research is warranted to explore the full clinical utility of this advanced imaging technology.