SU-E-T-111: Single Line Multi-Detector Scintillation Dosimetry: Demonstration of Feasibility

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Scintillation Detection

Background:

• Accurate radiation dose measurement is critical in radiation therapy.
• Traditional dosimetry methods can have limitations in complex irradiation scenarios.
• Developing novel dosimetry systems is essential for improving treatment precision.

Purpose of the Study:

• To evaluate the feasibility of using multiple scintillators on a single optical fiber for radiation dose measurements.
• To assess the linearity and dose rate dependence of a multi-scintillator system.
• To compare multi-scintillator measurements with established dosimetry techniques.

Main Methods:

• Two transparent scintillators (CsI and plastic) were coupled to a single fiber optic line.
• The system was irradiated with a 6 MV X-ray beam, and spectra were analyzed.
• Dose linearity and dose rate independence were tested by varying radiation output and dose rate.
• Unequal doses were delivered by modifying collimator settings and phantom attenuation.

Main Results:

• Scintillation spectra matched published data and remained stable with phantom depth.
• The multi-scintillator system demonstrated strict linearity (1.3-31 cGy) and dose rate independence (100-600 MU/min).
• Measurements showed good agreement (within +/- 3%) with ion chamber dosimetry.

Conclusions:

• Multi-probe scintillation dosimetry using a single optical fiber is feasible under therapeutic irradiation conditions.
• Distinct spectroscopic responses of multiple scintillators enable accurate dose determination.
• This technique supports absolute dose calibration for specific beam energies and detector arrangements.