Highlights
- •The egs_chamber determined the field output correction factors of RPLGD and CC01.
- •The field output correction factors were validated against IAEA-AAPM TRS-483.
- •The parallel orientation improved the small field output factors of RPLGD.
- •The volume averaging effect was small for RPLGD in parallel orientation.
- •RPLGD in parallel orientation is practical for field sizes down to 0.6 × 0.6 cm2.
Abstract
Purpose
To determine the field output correction factors of the radiophotoluminescence glass
dosimeter (RPLGD) in parallel and perpendicular orientations with reference to CC01,
the ionization chamber.
Methods
The dose to a small water volume and the sensitive volume of the RPLGD and the IBA-CC01
were determined for 6-MV, 100-cm SAD, 10-cm depth using egs_chamber user-code. The
RPLGD in perpendicular and parallel orientations to the beam axis were studied. The
field output correction factors of each detector for 0.5 × 0.5 to 10 × 10 cm2 field sizes were determined. These field output correction factors were validated
by comparing field output factors against data determined from IAEA-AAPM TRS-483 code
of practice.
Results
The field output correction factors of all detectors were within 5% for field sizes
down to 0.8 × 0.8 cm2. For 0.5 × 0.5 cm2, the field output correction factors of CC01, RPLGD in perpendicular and parallel
orientations differed from unity by 14%, 19%, and 5%, respectively. The percentage
difference between field output factors determined using RPLGD and CC01 data, corrected
using the field output correction factors determined in this work and measurements
with CC01 data corrected using TRS-483, was less than 3% for all field sizes, except
for the smallest field size of RPLGD in perpendicular orientation and the CC01.
Conclusions
The field output correction factors of RPLGD and CC01 are reported. The validation
proves that RPLGD in parallel orientation combined with the field output correction
factors is the most suitable for determining the field output factors for the smallest
field used in this study.
Keywords
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References
- Dosimetry of Small Static Fields used in External Beam Radiotherapy: An IAEA–AAPM International Code of Practice for Reference and Relative Dose Determination.Technical Report Series No.483. 2017; : Vienna
- A new formalism for reference dosimetry of small and nonstandard fields.Med Phys. 2008; 35: 5179-5186https://doi.org/10.1118/1.3005481
- Detector to detector corrections: A comprehensive experimental study of detector specific correction factors for beam output measurements for small radiotherapy beams.Med Phys. 2014; 41: 072103https://doi.org/10.1118/1.4883795
- Output correction factors for nine small field detectors in 6 MV radiation therapy photon beams: A PENELOPE monte carlo study.Med Phys. 2014; 41: 041711https://doi.org/10.1118/1.4868695
- Implementing a newly proposed Monte Carlo based small field dosimetry formalism for a comprehensive set of diode detectors.Med Phys. 2011; 38: 6592-6602https://doi.org/10.1118/1.3658572
- Monte Carlo modelling of diode detectors for small field MV photon dosimetry: Detector model simplification and the sensitivity of correction factors to source parameterization.Phys Med Biol. 2012; 57: 5141-5153https://doi.org/10.1088/0031-9155/57/16/5141
- Calculation of k Q clin, Q msr f clin, f msr for several small detectors and for two linear accelerators using Monte Carlo simulations.Med Phys. 2011; 38: 6513-6527https://doi.org/10.1118/1.3660770
- Field-size correction factors of a radiophotoluminescent glass dosimeter for small-field and intensity-modulated radiation therapy beams.Med Phys. 2018; 45: 382-390https://doi.org/10.1002/mp.12665
- Small field detector correction factors k Q clin, Q msrf clin, f msr for silicon-diode and diamond detectors with circular 6 MV fields derived using both empirical and numerical methods.Med Phys. 2016; 43: 411-423https://doi.org/10.1118/1.4938584
- Field correction factors for a PTW-31016 Pinpoint ionization chamber for both flattened and unflattened beams. Study of the main sources of uncertainties.Med Phys. 2017; 44: 1930-1938https://doi.org/10.1002/mp.12189
- Correction factor measurements for multiple detectors used in small field dosimetry on the Varian Edge radiosurgery system.Med Phys. 2015; 42: 5370-5376https://doi.org/10.1118/1.4928602
- Dosimetry of small static fields used in external photon beam radiotherapy: Summary of TRS-483, the IAEA–AAPM international Code of Practice for reference and relative dose determination.Med Phys. 2018; 45: e1123-45https://doi.org/10.1002/mp.13208
- Dosimetric properties of radiophotoluminescent glass rod detector in high-energy photon beams from a linear accelerator and Cyber-Knife.Med Phys. 2004; 31: 1980-1986https://doi.org/10.1118/1.1758351
- Investigation of the dosimetric characteristics of radiophotoluminescent glass dosimeter for high-energy photon beams.J Radiat Res Appl Sci. 2019; 12: 65-71https://doi.org/10.1080/16878507.2019.1594092
- Measurements of Gamma-Knife helmet output factors using a radiophotoluminescent glass rod dosimeter and a diode detector.Med Phys. 2003; 30: 1976-1981https://doi.org/10.1118/1.1587451
- Glass rod detectors for small field, stereotactic radiosurgery dosimetric audit.Med Phys. 2005; 32: 726-732https://doi.org/10.1118/1.1861155
- A geometrical model for the Monte Carlo simulation of the TrueBeam linac.Phys Med Biol. 2015; 60: N219-N229https://doi.org/10.1088/0031-9155/60/11/N219
- On the effective point of measurement in megavoltage photon beams.Med Phys. 2006; 33: 1829-1839https://doi.org/10.1118/1.2201147
- Experimental validation of recommended msr-correction factors for the calibration of Leksell Gamma Knife® Icontm unit following IAEA TRS-483.Phys Med Biol. 2020; 65: 65003https://doi.org/10.1088/1361-6560/ab6953
- Characterizing the influence of detector density on dosimeter response in non-equilibrium small photon fields.Phys Med Biol. 2012; 57: 4461-4476https://doi.org/10.1088/0031-9155/57/14/4461
- On the correction, perturbation and modification of small field detectors in relative dosimetry.Phys Med Biol. 2014; 59: 5937-5952https://doi.org/10.1088/0031-9155/59/19/5937
- Experimental investigation on the accuracy of plastic scintillators and of the spectrum discrimination method in small photon fields.Med Phys. 2017; 44: 654-664https://doi.org/10.1002/mp.12064
- Modeling the primary source intensity distribution: Reconstruction and inter-comparison of six Varian TrueBeam sources.Phys Med Biol. 2019; 64: 135005https://doi.org/10.1088/1361-6560/ab1ccc
- The impact of corrected field output factors based on IAEA/AAPM code of practice on small-field dosimetry to the calculated monitor unit in eclipseTM treatment planning system.J Appl Clin Med Phys. 2020; : 1-11https://doi.org/10.1002/acm2.12855
- Establishment of postal audit system in intensity-modulated radiotherapy by radiophotoluminescent glass dosimeters and a radiochromic film.Phys Medica. 2018; 48: 119-126https://doi.org/10.1016/j.ejmp.2018.03.013
- Feasibility study of radiophotoluminescent glass rod dosimeter postal dose intercomparison for high energy photon beam.Appl Radiat Isot. 2009; 67: 324-328https://doi.org/10.1016/j.apradiso.2008.09.018
Wesolowska PE, Cole A, Santos T, Bokulic T, Kazantsev P, Izewska J. Characterization of three solid state dosimetry systems for use in high energy photon dosimetry audits in radiotherapy. Radiat Meas 2017;106:556–62. https://doi.org/10.1016/j.radmeas.2017.04.017.
- Impact of testicular shielding in liposarcoma to scrotum by using radio-photoluminescence glass dosimeter (Rplgd): A case report.Radiat Oncol J. 2018; 36: 248-253https://doi.org/10.3857/roj.2018.00143
Article info
Publication history
Published online: July 16, 2021
Accepted:
July 5,
2021
Received in revised form:
June 24,
2021
Received:
May 26,
2021
Identification
Copyright
© 2021 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
