Photon dosimetry methods outside the target volume in radiation therapy: Optically stimulated luminescence (OSL), thermoluminescence (TL) and radiophotoluminescence (RPL) dosimetry

Željka Knežević (1) , Liliana Stolarczyk (2) , Igor Bessières (3) , jean-marc bordy (4) , Saveta Miljanić (1) , Paweł Olko (2)

1 Rudjer Boskovic Institute [Zagreb]
2 Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, 31-342 Krakow, Poland
3 LM2S (CEA, LIST) - Laboratoire Modélisation et Simulation de Systèmes (CEA, LIST)
4 LNHB (CEA, LIST) - Laboratoire National Henri Becquerel (CEA, LIST)

Dosimetry methods outside the target volume are still not well established in radiotherapy. Luminescence detectors due to their small dimensions, very good sensitivity, well known dose and energy response are considered as an interesting approach in verification of doses outside the treated region. The physical processes of thermoluminescence (TL), radiophotoluminescence (RPL) and optically stimulated luminescence (OSL) are very similar and can be described in terms of the energy band model of electron-hole production following irradiation. This work is a review of the main dosimetric characteristics of luminescence detectors which were used in experiments performed by EURADOS Working Group 9 for in-phantom measurements of secondary radiation (scattered and leakage photons). TL LiF:Mg,Ti detectors type MTS-7 (IFJ PAN, Poland), types TLD-100 and TLD-700 (Harshaw), OSL Al2O3:C detectors type nanoDot™ (Landauer Inc.) and RPL rod glass elements type GD-352M (Asahi Techno Glass Coorporation) are described. The main characteristics are discussed, together with the readout and calibration procedures which lead to a determination of absorbed dose to water. All dosimeter types used show very good uniformity, batch reproducibility and homogeneity. For improved accuracy, individual sensitivity correction factors should be applied for TL and OSL dosimeters while for RPL dosimeters there is no need for individual sensitivity corrections. The dose response of all dosimeters is linear for a wide range of doses. The energy response of GD-352M type dosimeters (with Sn filter) used for out-of-field measurements is flat for medium and low energy X-rays. The energy dependence for TLDs is low across the range of photon energies used and the energy correction was neglected. A significant over response of Al2O3:C OSLDs irradiated in kilovoltage photon beams was taken into account. The energy correction factor fen was calculated by using the 2006 PENELOPE Monte Carlo code. With suitable calibration, all dosimeter types are appropriate for out-of-field dose measurements as well as for the in-phantom measurements of radiotherapy MV X-rays beams.

Mots clés: 18 MV IMRT; DOSE MEASUREMENT; CLINICAL APPLICATION; radiotherapy; Thermoluminescent dosimeter (TLD); Optically stimulated dosimeter (OSLD); Photon dosimetry methods; Radiophotoluminescent dosimeter (RPL); Out-of-field dosimetry in radiation therapy; OUT-OF-FIELD; HIGH-ENERGY PHOTON; IN-VIVO DOSIMETRY; TREATMENT PLANNING SYSTEM; EARLY BREAST-CANCER; GLASS ROD DETECTOR; CO-60 GAMMA-RAYS; Dosimetry; ionizing radiation; Radioactivity

Domaines: Ingénierie biomédicale; Modélisation et simulation; Physique Nucléaire Expérimentale [nucl-ex]; Instrumentations et Détecteurs [physics.ins-det]; Cancer; Optique / photonique

Željka Knežević, Liliana Stolarczyk, Igor Bessières, jean-marc bordy, Saveta Miljanić, et al.. Photon dosimetry methods outside the target volume in radiation therapy: Optically stimulated luminescence (OSL), thermoluminescence (TL) and radiophotoluminescence (RPL) dosimetry. Radiation Measurements, 2013, 57, pp.9 - 18. ⟨10.1016/j.radmeas.2013.03.004⟩. ⟨cea-01802346⟩