Carbon range verification with 718 keV Compton imaging

Area of Science:

• Medical Physics
• Radiation Oncology
• Nuclear Instrumentation

Background:

• Carbon ion radiotherapy offers superior dose distribution and biological effectiveness.
• Beam range uncertainties in carbon ion therapy can compromise treatment efficiency.
• Real-time monitoring of clinical beams is crucial for precise dose delivery.

Purpose of the Study:

• To develop and evaluate a Compton camera for real-time imaging of prompt gamma emissions.
• To assess the feasibility of using this camera for monitoring clinical carbon ion beams.
• To address beam range uncertainties in carbon ion radiotherapy.

Main Methods:

• Real-time detection and imaging of 718 keV prompt gamma emissions using a Si/CdTe Compton camera.
• Experiments conducted on graphite phantoms with clinical 290 MeV/u carbon ion beams.
• Compton image reconstruction using simple back-projection methods.

Main Results:

• The peak intensity position in reconstructed images was found a few millimeters below the Bragg peak.
• Dual- and triple-energy window images were unaffected by scattered gammas.
• Peak intensity positions in energy-windowed images closely matched those in the primary reconstructed images.

Conclusions:

• The developed Compton camera system is feasible for real-time beam monitoring in carbon ion radiotherapy.
• This technology can potentially improve the precision and safety of carbon ion treatments.
• The findings support the use of prompt gamma imaging for quality assurance in particle therapy.