Proton range verification using a range probe: definition of concept and initial analysis.

Area of Science:

• Medical Physics
• Radiation Oncology
• Particle Physics

Background:

• Proton therapy precision relies on accurate range determination.
• In vivo range verification is crucial for improving radiotherapy quality.
• Current methods lack sufficient accuracy for real-time range assessment.

Purpose of the Study:

• Introduce and assess the feasibility of a 'range probe' concept for in vivo proton range verification.
• Evaluate the potential of the range probe to detect errors in range calculations and patient setup.
• Determine the required detector specifications for high-resolution range measurements.

Main Methods:

• Monte Carlo (MC) simulations using VMCpro software.
• Simulated low-dose, high-energy proton pencil beams traversing patient CT data.
• Analysis of the integral Bragg peak measured by a simulated multi-layer detector (range telescope).
• Investigation of sensitivity to CT variations and positional shifts.

Main Results:

• Potential for 1 mm range resolution in homogeneous tissues with a 4 mm detector.
• Bragg peak shape changes in heterogeneous tissues can detect patient setup errors.
• The range probe concept demonstrates feasibility for high-resolution verification.

Conclusions:

• The proton 'range probe' is a feasible method for in vivo range verification in proton therapy.
• Experimental validation is planned using various range telescope detectors.
• This technique could significantly enhance the accuracy and safety of proton radiotherapy.