WE-G-BRB-06: Real-Time Radiation Field Tracking Using Long Scintillating Fibers

Area of Science:

• Medical Physics
• Radiation Oncology
• Instrumentation

Background:

• Quality assurance is critical in radiotherapy, especially for small field and dynamic treatments.
• Real-time monitoring of radiation fields is essential for ensuring treatment accuracy and patient safety.

Purpose of the Study:

• To develop and validate a novel radiation tracking system for real-time measurement of small radiation fields.
• To assess the system's capability in measuring both position and energetic fluence.

Main Methods:

• A system utilizing 60 parallel scintillating fibers coupled to a CCD camera was designed.
• Optical attenuation was used to determine the interaction position of a small photon radiation field.
• Energetic fluence was calculated from light fluxes, corrected for position-dependent attenuation and scintillation efficiency.

Main Results:

• The system achieved high accuracy in position measurement, with mean errors of 0.1 mm (perpendicular) and 0.8 mm (parallel) to the fiber array.
• Energetic fluence was determined with a mean error of 0.5% and a maximum error of 2.2%.
• The system demonstrated robustness against treatment couch positioning errors.

Conclusions:

• A long scintillating fiber array can effectively track the position and energetic fluence of small radiation fields in real-time.
• This methodology offers a promising solution for quality assurance in photon and particle radiation therapy.
• The developed system has the potential to significantly improve the precision of advanced radiotherapy techniques.