Technical Note: A fast and monolithic prototype clinical proton radiography system optimized for pencil beam scanning

Area of Science:

• Medical Physics
• Radiation Oncology
• Imaging Technology

Background:

• Proton therapy requires precise imaging for accurate dose delivery.
• Existing imaging systems can be complex and costly.
• There is a need for efficient and accessible pretreatment imaging solutions.

Purpose of the Study:

• To demonstrate a cost-effective proton imaging system using scintillator technology.
• To achieve high performance and simplified design for clinical translation.
• To develop a prototype for pretreatment imaging in proton radiation therapy.

Main Methods:

• Utilized scintillating fiber trackers and a residual energy detector with photomultiplier tubes (PMTs).
• Employed silicon photomultipliers (SiPMs) for signal multiplexing to reduce electronic channels.
• Developed a robust calibration method for accurate proton imaging and patient-specific scan patterns.

Main Results:

• Achieved accurate residual range measurements, validated by water-equivalent thickness measurements.
• Demonstrated the capability of producing proton radiographs with minimal excess dose.
• Confirmed the feasibility of imaging with a compact range detector using patient-specific scan patterns.

Conclusions:

• A prototype clinical proton radiography system has been successfully developed.
• The system is optimized for pencil beam scanning, reducing size and complexity.
• The technology shows potential for straightforward integration into clinical proton therapy workflows.