A Comparative Analysis of Thermoluminescence Dosimetry, Ionization Chambers, and PTW Type 0.6 Chambers in Radiotherapy Dose Measurement

Abstract

Ensuring accurate and dependable dose measurement in radiotherapy is crucial for optimizing treatment results while minimizing the risks of radiation to healthy tissues. This study compares thermoluminescence dosimetry (TLD), ionization chambers, and PTW Type 0.6 chambers in radiotherapy dose measurement. Using a Siemens Artiste® linear accelerator, dose measurements were performed at 1.5 cm and 5 cm depths within a water-equivalent phantom across doses from 20 cGy to 500 cGy. TLDs, while highly sensitive and suitable for various radiation energies, showed greater deviations at higher doses, with average errors of -2.58% at 1.5 cm and -2.88% at 5 cm. Ionization chambers, especially the PTW Type 0.6 chambers, provided superior accuracy in high-dose applications, though they also exhibited significant variation at higher doses. At 1.5 cm depth, IC1 and IC2 showed average errors of -2.30% and 1.92%, respectively, while at 5 cm depth, the errors were -2.49% (IC1) and -2.10% (IC2). The study highlights the importance of selecting appropriate dosimeters based on specific clinical scenarios and maintaining rigorous calibration and quality assurance protocols to ensure accurate dose measurements in radiotherapy. Each dosimeter type offers unique benefits: TLDs for general dosimetry and in vivo measurements, ionization chambers for real-time monitoring, and PTW Type 0.6 chambers for small field dosimetry.