Evaluation of optically stimulated luminescence dosimeter for exit dose in vivo dosimetry in radiation therapy

Ponmalar, Retna; Ravikumar, M; Sathiyan, S; Ganesh, K M; Raman, Arun; Godson, Henry Finlay

doi:10.4103/0973-1482.191066

Cited by 2 publications

(3 citation statements)

References 25 publications

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“…As passive dosimeters with high sensitivity, OSLDs are promising detectors for dosimetry QA checks, endto-end tests, remote audits, surface dose determination, and in vivo dosimetry (Dunn et al 2013, Zhuang and Olch 2014, Alves et al 2015, Zakjevskii et al 2016, Ponmalar et al 2018. However, a large number of dependencies has been identified (Kry et al 2020), suggesting that calibration, irradiation, read-out and handling parameters need to be carefully controlled for high-fidelity dosimetry.…”

Section: B Qmentioning

confidence: 99%

Dose-response dependencies of OSL dosimeters in conventional linacs and 1.5T MR-linacs: an experimental and Monte Carlo study

Episkopakis,

Margaroni,

Kanellopoulou

et al. 2023

Phys. Med. Biol.

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Objective: This work focuses on the Optically Stimulated Luminescence Dosimetry (OSLD) dose-response characterization, with emphasis on 1.5T MR-Linacs.Approach: Throughout this study, the nanoDots OSLDs (Landauer, USA) were considered. In groups of three, the mean OSLD response was measured in a conventional linac and an MR-Linac under various irradiation conditions to investigate (i) dose-response linearity with and without the 1.5T magnetic field, (ii) signal fading rate and its dependencies, (iii) beam quality, detector orientation and dose rate dependencies in a conventional linac, (iii) potential MR imaging related effects on OSLD response and (iv) detector orientation dependence in an MR-Linac. Monte Carlo calculations were performed to further quantify angular dependence after rotating the detector around its central axis parallel to the magnetic field, and determine the magnetic field correction factors, kB,Q, for all cardinal detector orientations.Main results: OSLD dose-response supralinearity in an MR-Linac setting was found to agree within uncertainties with the corresponding one in a conventional linac, for the axial detector orientation investigated. Signal fading rate does not depend on irradiation conditions for the range of 3-30 days considered. OSLD angular (orientation) dependence is more pronounced under the presence of a magnetic field. OSLDs irradiated with and without real-time T2w MR imaging enabled during irradiation yielded the same response within uncertainties. kB,Q values were determined for all three cardinal orientations. Corrections needed reached up to 6.4%. However, if OSLDs are calibrated in the axial orientation and then irradiated in an MR-Linac placed again in the axial orientation (perpendicular to the magnetic field), then simulations suggest that kB,Q can be considered unity within uncertainties, irrespective of the incident beam angle.Significance: This work contributes towards OSLD dose-response characterization and relevant correction factors availability. OSLDs are suitable for QA checks in MR-based beam gating applications and in vivo dosimetry in MR-Linacs.

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Section: B Qmentioning

confidence: 99%

Dose-response dependencies of OSL dosimeters in conventional linacs and 1.5T MR-linacs: an experimental and Monte Carlo study

Episkopakis,

Margaroni,

Kanellopoulou

et al. 2023

Phys. Med. Biol.

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“…Some papers reported that the accuracy of in vivo dosimetry using TLDs was about 10%–15% 11,12 . Other tools available for in vivo dosimetry include optically stimulated luminescent dosimeters (OSLDs), radio‐photoluminescent glass dosimeters (RPLGDs), and radiochromic films 13–22 . OSLDs and RPLGDs are independent of beam energy for MeV beams and less dependent on the beam angle, whereas radiochromic films are able to provide two‐dimensional dosimetric information.…”

Section: Introductionmentioning

confidence: 99%

“…11,12 Other tools available for in vivo dosimetry include optically stimulated luminescent dosimeters (OSLDs), radio-photoluminescent glass dosimeters (RPLGDs), and radiochromic films. [13][14][15][16][17][18][19][20][21][22] OSLDs and RPLGDs are independent of beam energy for MeV beams and less dependent on the beam angle, whereas radiochromic films are able to provide two-dimensional dosimetric information. However, passive detectors cannot provide real-time measurements, and there is an inconvenience of having to perform post-processing to obtain results.…”

Section: Introductionmentioning

confidence: 99%

Development of a real‐time in vivo dosimetry tool for electron beam therapy using a flexible thin film solar cell coated with scintillator powder

Jeong

Kwon

et al. 2022

Medical Physics

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Purpose A real‐time solar cell based in vivo dosimetry system (SC‐IVD) was developed using a flexible thin film solar cell and scintillating powder. The present study evaluated the clinical feasibility of the SC‐IVD in electron beam therapy. Methods A thin film solar cell was coated with 100 mg of scintillating powder using an optical adhesive to enhance the sensitivity of the SC‐IVD. Calibration factors were obtained by dividing the dose, measured at a reference depth for 6–20 MeV electron beam energy, by the signal obtained using the SC‐IVD. Dosimetric characteristics of SC‐IVDs containing variable quantities of scintillating powder (0–500 mg) were evaluated, including energy, dose rate, and beam angle dependencies, as well as dose linearity. To determine the extent to which the SC‐IVD affected the dose to the medium, doses at R90 were compared depending on whether the SC‐IVD was on the surface. Finally, the accuracy of surface doses measured using the SC‐IVD was evaluated by comparison with surface doses measured using a Markus chamber. Results Charge measured using the SC‐IVD increased linearly with dose and was within 1% of the average signal according to the dose rate. The signal generated by the SC‐IVD increased as the beam angle increased. The presence of the SC‐IVD on the surface of a phantom resulted in a 0.5%–2.2% reduction in dose at R90 for 6–20 MeV electron beams compared with the bare phantom. Surface doses measured using the SC‐IVD system and Markus chamber differed by less than 5%. Conclusions The dosimetric characteristics of the SC‐IVD were evaluated in this study. The results showed that it accurately measured the surface dose without a significant difference of dose in the medium when compared with the Markus chamber. The flexibility of the SC‐IVD allows it to be attached to a patient's skin, enabling real‐time and cost‐effective measurement.

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Evaluation of optically stimulated luminescence dosimeter for exit dose in vivo dosimetry in radiation therapy

Cited by 2 publications

References 25 publications

Dose-response dependencies of OSL dosimeters in conventional linacs and 1.5T MR-linacs: an experimental and Monte Carlo study

Dose-response dependencies of OSL dosimeters in conventional linacs and 1.5T MR-linacs: an experimental and Monte Carlo study

Development of a real‐time in vivo dosimetry tool for electron beam therapy using a flexible thin film solar cell coated with scintillator powder

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