High-precision dosimetry for radiotherapy using the optically stimulated luminescence technique and thin Al₂O₃:C dosimeters

Abstract

The potential of using the optically stimulated luminescence (OSL) technique with aluminium oxide (Al(2)O(3):C) dosimeters for a precise and accurate estimation of absorbed doses delivered by high-energy photon beams was investigated. This study demonstrates the high reproducibility of the OSL measurements and presents a preliminary determination of the depth-dose curve in water for a 6 MV photon beam from a linear accelerator. The uncertainty of a single OSL measurement, estimated from the variance of a large sample of dosimeters irradiated with the same dose, was 0.7%. In the depth-dose curve obtained using the OSL technique, the difference between the measured and expected doses was < or =0.7% for depths between 1.5 and 10 cm, and 1.1% for a depth of 15 cm. The readout procedure includes a normalization of the response of the dosimeter with respect to a reference dose in order to eliminate variations in the dosimeter mass, dosimeter sensitivity, and the reader's sensitivity. This may be relevant for quality assurance programmes, since it simplifies the requirements in terms of personnel training to achieve the precision and accuracy necessary for radiotherapy applications. We concluded that the OSL technique has the potential to be reliably incorporated in quality assurance programmes and dose verification.

Optically stimulated luminescencein vivodosimetry for radiotherapy: physical characterization and clinical measurements in60Co beams

“…Schembri and Heijmen (2007) who have investigated OSL film dosimeters found an inter film response variation in a range of 1% to 3.2%. Better results have been reported by Yukihara et al (2005) in a reproducibility test with ten packages, each containing five OSL dosimeters, irradiated in a 6MV photon beam. They found that the maximum difference between the mean package readings from the overall mean was 0.7%.…”

Characterization of a Commercially-Available, Optically-Stimulated Luminescent Dosimetry System for Use in Computed Tomography

“…The OSL process is similar to that of thermoluminescence (TL), with the primary difference being that an optical stimulus is used in OSL instead of a thermal or heat stimulus in the TL process to induce luminescence of the irradiated material. After irradiation, light-emitting diodes (LEDs) supply the optical energy required to release the stored OSL signal; this signal is directly proportional to the dose absorbed by the dosimeter (Yukihara et al 2005).…”

Highly sensitive Europium doped SrSO4 OSL nanophosphor for radiation dosimetry applications

“…[12][13][14][15][16]. More recently, OSL of borate and silicates doped with Ce, Eu, Sm and Cu ions have been reported [8][9][10][11][12]. Attempts are also made to study materials like BeO [17], NaMgF 3 :Eu [18], MgO:Tb [19], LiMgPO 4 :Tb,B [20], LiAlO 2 [21], YAG:C [22], Cu doped Alkali fluorosilicates [23][24][25], Li 3 PO 4 :Cu [26], SiO 2 :Ag [27], KBr:Eu [28], (NH 4 ) 2 SiF 6 :Tl [29], LiAlO 2 :Tb,Ce [30,31], ZnAl 2 O 4 :Tb [32], MgAl 2 O 4 :Tb [33] etc.…”

“…Carbon doped alumina (Al 2 O 3 :C) is the most popular phosphor material with the highest potential for OSL dosimetry due to its excellent dosimetric properties [1,2]. The application of OSL property of a-Al 2 O 3 :C single crystal has been established in personnel dosimetry [3,4], environmental dosimetry [5], medical dosimetry [6][7][8][9] and space dosimetry [10,11]. Although many OSL phosphors have been developed for dosimetric applications, the research is mainly centered on natural/synthetic quartz, feldspars, oxides, fluorides, chlorides etc.…”