Multichannel Dosimeter and $\alpha$-Al$_{2}$O$_{3}$:C Optically Stimulated Luminescence (OSL) Fiber Sensors for Use in Radiation Therapy—Evaluation With Photon Beams
Abstract
A multichannel OSL fiber optic dosimeter based on optically stimulated luminescence (OSL) of alumina is proposed for online in vivo dosimetry (IVD) in radiation therapy (RT). Two types of dosimetric-grade Al$_2$ O$_3$ : C crystals are compared and show different behavior according to manufacturing process. Metrological validations have been performed with a Saturne 43 LINAC in reference conditions at CEA LIST LNHB (French Ionizing Radiation Reference Laboratory). The dose response of OSL integrals under photon beam irradiation (6, 12, and 20 MV) show sublinearity behavior modeled by second-order equations and exhibit a small energy dependence (between 0.7% and 1.4%), explained by a modified intermediate cavity model adapted to a LINAC photon spectrum. Preclinical tests at Institut Gustave Roussy (IGR) prove that a proper design for a PMMA build-up cap leads to a low dependence vs photon beam orientation ($\pm$1.5% and $\pm$0.9%) and vs field size in view of surface measurements.
Keywords
Optical Fiber Sensor (OFS)
radiotherapy
Optically Stimulated Luminescence (OSL)
alumina
Index Terms—In Vivo Dosimetry (IVD)
carbon
fibre optic sensors
dosimetry
linear accelerators
radiation therapy
Photonics
Crystals
Optical fiber sensors
Optical fibers
α-Al2O3:C
optically stimulated luminescence fiber sensors
multichannel OSL fiber optic dosimeter
online in vivo dosimetry
manufacturing process
metrological validations
Saturne 43 LINAC
CEA LIST LNHB
French ionizing radiation reference laboratory
photon beam irradiation
second-order equations
modified intermediate cavity model
LINAC photon spectrum
photon beam orientation
surface measurements
voltage 6 MV to 20 MV
Al2O3:C
Origin : Files produced by the author(s)
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