Optimizing a three-stage Compton camera for measuring prompt gamma rays emitted during proton radiotherapy.

Area of Science:

• Medical Physics
• Nuclear Instrumentation
• Radiotherapy Physics

Background:

• Proton beam radiotherapy offers precise dose delivery.
• Monitoring secondary prompt gamma rays can verify proton range.
• Current detection methods face limitations in efficiency and imaging.

Purpose of the Study:

• To develop an optimized three-stage Compton camera for prompt gamma ray detection.
• To assess the feasibility of using this camera for imaging during proton therapy.

Main Methods:

• Geant4 simulations were used to model a three-stage Compton camera with high-purity germanium detectors.
• Detector dimensions were optimized for maximum efficiency using an isotropic gamma source.
• The camera's efficiency was calculated using a proton beam irradiating a tissue phantom.

Main Results:

• Optimized detector geometry was determined for improved detection efficiency.
• Overall detection efficiencies ranged from approximately 10^-6 to 10^-3 prompt gammas per incident proton.
• Simulations indicate sufficient detection rates for imaging applications.

Conclusions:

• A three-stage Compton camera is a feasible tool for measuring prompt gamma rays in proton therapy.
• The developed camera design shows potential for real-time monitoring and imaging of proton therapy treatments.
• This technology could enhance treatment verification and accuracy in proton radiotherapy.