A PMMA Optical Fibre Sensor for Clinic Radiotherapy Real-Time Monitoring Application

A PMMA optical fibre sensor for real-time monitoring of radiotherapy dosimetry is presented. The sensor is based on a X-Ray sensitive scintillating material filled into the micro hole located at one end of the fibre. The scintillating material terbium-doped gadolinium oxysulfide (Gd₂O₂S: Tb) fluoresces under the X-Ray beam delivered with a range of dose rate from 100MU/min to 600MU/min, and the signal intensity delivered using OFS shows great linearity with the detector background noise removed. The results represent an excellent linear relationship (R² of 1) between the output intensity using OFS and the simultaneous measurements of dose which was simultaneously measured and verified using an Ionsitation Chamber IC, demonstrating the potential of the novel OFS for use in radiotherapy dosimetry applications.