Optically stimulated Al₂O₃:C luminescence dosimeters for teletherapy: H_p(10) performance evaluation

The performance of optically stimulated luminescence dosimeters (OSLDs, Al₂O₃:C) was evaluated in terms of the operational quantity of H_P(10) in Co-60 external beam teletherapy unit. The reproducibility, signal depletion, and dose linearity of each dosimeter was investigated. For ten repeated readouts, each dosimeter exposed to 50mSv was found to be reproducible below 1.9 ± 3% from the mean value, indicating good reader stability. Meanwhile, an average signal reduction of 0.5% per readout was found. The dose response revealed a good linearity within the dose range of 5-50mSv having nearly perfect regression line with R² equals 0.9992. The accuracy of the measured doses were evaluated in terms of operational quantity H_P(10), wherein the trumpet curve method was used respecting the 1990 International Commission on Radiological Protection (ICRP) standard. The accuracy of the overall measurements from all dosimeters was discerned to be within the trumpet curve and devoid of outlier. It is established that the achieved OSL Al₂O₃:C dosimeters are greatly reliable for equivalent dose assessment.