Application of glow curve analysis methods to radiotherapy mailed dosimetry with LiF TLD-100

Abstract

This paper presents the results obtained in a study of LiF TLD-100 performance for mailed dosimetry in radiotherapy, using glow curve analysis of TL evaluation and reusable chips. An excellent reusability is assured by a simple thermal treatment of 1 h at 400 degrees C followed by a controlled and reproducible cooling to room temperature that accurately reproduces the sensitivity of the detectors. Particular attention was devoted to studying sensitivity changes during room temperature storage of TLD-100 detectors. These changes can be one of the major sources of uncertainty in mailed dosimetry, where long intervals can occur between detector preparation, irradiation and readout. Based on the features of the individual peak evolution during storage a rather simple method to correct for these sensitivity modifications is proposed. The analysis of the different influential factors permitted us to estimate a combined uncertainty for the measurement of absorbed doses within the 0.5-4 Gy range of 1.0%.

Versatility of thermoluminescence materials and radiation dosimetry – A review

“…The materials used for radiation detection materials are mostly single crystal, ceramics and glass such as Al 2 O 3 :C single crystal, LiF ceramic, CaSO 4 :Dy . Glass has technological relevance in comparison with crystalline system.…”

Radiation effect on the UV-green thermally stimulated luminescence emission of a natural Na-rich aluminosilicate

“…can be calculated using the Glow Curve Fitting (GCF) (Muñiz et al, 1995;Gomez-Ros et al, 2002), Whole Glow Peak (WGP) (Kalita and Chithambo, 2017), Peak Shape (PS) (Aslar et al, 2017;Keskin et al, 2018), Variable Heating Rate (VHR) (Topaksu et al, 2015;Aslar et al, 2017) and Initial Rise (IR) method (Chen and McKeever, 1997;Correcher et al, 2008), among others. The main advantage of the last method is that the E a parameter can be estimated regardless of the b value, although is a sensitive method to infer potential thermal pretreatments or changes in the heating rate.…”

A study of LiF GR-200 for radiotherapy mailed dosimetry

“…The simple dose dependence of GR-200 is in contrast with the supralinear dependence of TLD-100. In Muñiz et al (1995) the best fit was obtained with a quadratic expression. The proportionality between TL and dose found for GR-200 is a good point in favour of this material, as calibration can be simplified requiring fewer calibration points than with TLD-100.…”

“…around 1% (1σ ), and certainly lower than 5%. In a recent paper from our group (Muñiz et al 1995) it has been shown that using simple but carefully designed and applied TL procedures it is possible to obtain these accuracy standards with LiF:Mg,Ti (TLD-100). Glow curve analysis was employed to extract the dosimetric information contained in the TL signals, and also to study the response stability of TLD-100 in working conditions typical of a mailed system with long intervals between the three main measurement steps: dosimeter preparation, irradiation and the final evaluation.…”

“…All these useful properties make it interesting to study the performance of LiF GR-200 for mailed dosimetry, seeking improvements over the rather good TLD-100 results. In this study, the same approach employed with TLD-100 in the previous work (Muñiz et al 1995) has been followed applying glow curve analysis methods to evaluate prompt and delayed TL measurements.…”