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Response of a nanoDot OSLD system in megavoltage photon beams

      Highlights

      • The nanoDot OSLD response for radiotherapy was investigated as a function of energy, depth, field size, and angle.
      • The nanoDot responses at a 10-cm depth and 10 × 10-cm2 field agreed within 1% for 4–18-MV photons.
      • The angle dependence decreased by 5% and 3% at 6-MV and 15-MV photons for a parallel beam, respectively.

      Abstract

      Purpose

      The aim of this study was to investigate the response of a nanoDot optically stimulated luminescence dosimeter (OSLD) system in megavoltage photon beams.

      Methods

      The nanoDot response was compared with the ionization chamber measurements for 4–18-MV photons in a plastic water phantom. The response was also calculated by the Monte Carlo method. In addition, the perturbation correction factor, PQ, in the nanoDot cavity was calculated according to the Burlin’s cavity theory. The angular dependence of the nanoDot was evaluated using a spherical phantom.

      Results

      The calculated and measured nanoDot responses at a 10-cm depth and 10 × 10-cm2 field were in agreement within 1% for 4–18-MV. The response increased by 3% at a 20 × 20-cm2 field for the lower energy of 4 MV; however, it was constant within ±1% for 6–18 MV. The response was in a range from 1.0 to 0.99 for mean photon energy of more than 1.0 MeV but it increased with less than the 1.0 MeV. PQ for the nanoDot cavity was approximately constant at 0.96–0.97 for greater than and equal to 10 MV. The angular dependence decreased by 5% and 3% for 6 and 15 MV, respectively.

      Conclusions

      The nanoDot was energy-independent in megavoltage photon beams.

      Keywords

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      References

        • Dunn L.
        • Lye J.
        • Kenny J.
        • et al.
        Commissioning of optically stimulated luminescence dosimeters for use in radiotherapy.
        Radiat Meas. 2013; 51–52: 31-39
        • Lye J.
        • Dunn L.
        • Kenny J.
        • et al.
        Remote auditing of radiotherapy facilities using optically stimulated luminescence dosimeters.
        Med Phys. 2014; 41
        • Alvarez P.
        • Kry S.F.
        • Stingo F.
        • et al.
        TLD and OSLD dosimetry systems for remote audits of radiotherapy external beam calibration.
        Radiat Meas. 2017; 106: 412-415
        • Mrcela I.
        • Bokulic T.
        • Izewska J.
        • et al.
        Optically stimulated luminescence in vivo dosimetry for radiotherapy: physical characterization and clinical measurements in 60Co beams.
        Phys Med Biol. 2011; 56: 6065-6082
        • Wesolowska P.E.
        • Cole A.
        • Santos T.
        • et al.
        Characterization of three solid state dosimetry systems for use in high energy photon dosimetry audits in radiotherapy.
        Radiat Meas. 2017; 106: 556-562
        • Thistlethwaite J.
        • Johnson D.
        • Valentino D.J.
        microSTARiiTM – A new system for medical dosimetry; Part 1: Technology and Initial Performance.
        LANDAUER Technology Whitepaper, 2013
        • Yukihara E.
        • Mardirossian G.
        • Mirzasadeghi M.
        • et al.
        Evaluation of Al2O3: C optically stimulated luminescence (OSL) dosimeters for passive dosimetry of high-energy photon and electron beams in radiotherapy.
        Med Phys. 2008; 35: 260-269
        • Schembri V.
        • Heijmen B.J.
        Optically stimulated luminescence (OSL) of carbon-doped aluminum oxide (Al2O3:C) for film dosimetry in radiotherapy.
        Med Phys. 2007; 34: 2113-2118
        • Viamonte A.
        • da Rosa L.A.
        • Buckley L.A.
        • et al.
        Radiotherapy dosimetry using a commercial OSL system.
        Med Phys. 2008; 35: 1261-1266
        • Reft C.S.
        The energy dependence and dose response of a commercial optically stimulated luminescent detector for kilovoltage photon, megavoltage photon, and electron, proton, and carbon beams.
        Med Phys. 2009; 36: 1690-1699
        • Scaboro S.B.
        • Followill D.S.
        • Kerns J.R.
        • et al.
        Energy response of optically stimulated luminescent dosimeters for non-reference measurement location in a 6 MV photon beam.
        Phys Med Biol. 2012; 57: 2505-2515
        • Kim D.W.
        • Chung W.K.
        • Shin D.O.
        • et al.
        Dose response of commercially available optically stimulated luminescent detector, Al2O3: C for megavoltage photons and electrons.
        Radiat Prot Dosim. 2012; 149: 108-109
        • Kerns J.R.
        • Kry S.F.
        • Sahoo N.
        • et al.
        Angular dependence of the nanoDot OSL dosimeter.
        Med Phys. 2011; 38: 3955-3962
        • Lehmann J.
        • Dunn L.
        • Lye J.E.
        • et al.
        Angular dependence of the response of the nanoDot OSLD system for measurements at depth in clinical megavoltage beams.
        Med Phys. 2014; 41061712
        • Jursinic P.A.
        Angular dependence of dose sensitivity of nanoDot optically stimulated luminescent dosimeters in different radiation geometries.
        Med Phys. 2015; 42: 5633-5641
        • Zakjevskii V.
        • Knill C.
        • Rakowski J.
        • et al.
        Development and evaluation of an end-to-end test for head and neck IMRT with a novel multiple-dosimetric modality phantom.
        J Appl Clin Med Phys. 2016; 17: 497-510
        • Loughery B.
        • Knill C.
        • Silverstein E.
        • et al.
        Multi-institutional evaluation of end-to-end protocol for IMRT/VMAT treatment chains utilizing conventional linacs.
        Med Dosim. 2018; 18: 30020-30027
      1. IAEA, Absorbed dose determination in external beam radiotherapy: An international code of practice for dosimetry based on standards for absorbed dose to water. Technical Report Series No. 398 (IAEA, Vienna, 2000).

        • Wulff J.
        • Zink K.
        • Kawrakow I.
        Efficiency improvements for ion chamber calculations in high energy photon beams.
        Med Phys. 2008; 35: 1328-1336
      2. Kawrakow I, Mainegra-Hing E, Tessier F, et al. EGSnrc c++ class library. National Research Council of Canada Report. 2018; No. PIRS-898.

        • Rogers D.W.
        • Faddegon B.A.
        • Ding G.X.
        • et al.
        BEAM: a Monte Carlo code to simulate radiotherapy treatment units.
        Med Phys. 1995; 22: 503-524
      3. Rogers DW, Walters BR, Kawrakow I. BEAMnrc users Manual. National Research Council of Canada Report. 2018; No. PIRS-509 (A) revL.

        • Burlin T.E.
        A general theory of cavity ionization.
        Br J Radiol. 1966; 39: 727-734
        • Spencer L.V.
        • Atixx F.H.
        A theory of cavity ionization.
        Radiat Res. 1955; 3: 239-254
      4. Rogers DW, Kawrakow I, Mainegra-Hing E, et al. BRC User Code for EGSnrc. National Research Council of Canada Report. 2018; No. PIRS-702 (revC).

        • Seltzer S.M.
        • Hubbell J.H.
        Tables and graphs of photon mass attenuation coefficients and mass energy-absorption coefficients for photon energies 1 keV to 20 MeV for elements Z=1 to 92.
        The X-ray Attenuation and Absorption for Materials of Dosimetric Interest Database, NIST1995
        • Berger M.J.
        • Hubbell J.H.
        XCOM: Photon cross sections on a personal computer Report NBSIR87-3597.
        National Institute of Standards Technology, Gaithersburg, MD1987: 20899
        • Araki F.
        • Ohno T.
        The response of a radiophotoluminescent glass dosimeter in megavoltage photon and electron beams.
        Med Phys. 2014; 41122102