Measurement of LET (linear energy transfer) spectra using CR-39 at different depths of water irradiated by 171 MeV protons: A comparison with Monte Carlo simulation

Sahoo, G.S.; Tripathy, S.P.; Molokanov, A. G.; Aleynikov, V.E.; Sharma, S. D.; Bandyopadhyay, Tapas Kumar

doi:10.1016/j.nima.2016.02.038

Cited by 5 publications

(2 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Proton LET is notoriously difficult to measure directly with only a very limited number of devices commercially available such as the tissue-equivalent proportionality counter (TEPC), 19 silicon spectrometer, 20 or CR-39 etch detectors. 21 Other authors have presented creative strategies for simultaneous proton dose and LET measurements such as the use of organic scintillators, 22 thermoluminescent dosimeters 23,24 (TLDs), Al 2 O 3 :C OSLD 25 detectors, and Gafchromic EBT3 films. 26 In this work, we present a novel solution to this problem by proposing the use of a proton energy dependent high Z eff storage phosphor (Z eff = 49, BaFBr 0.85 I 0.15 :Eu 2+ ) in conjunction with a near-proton energy independent low Z eff storage phosphor (Z eff = 18, KCl:Eu 2+ ).…”

Section: Introductionmentioning

confidence: 99%

“…Ideally, these new dosimeters should have the ability to measure both proton dose and LET values simultaneously for their effective and quick implementation in proton clinics. Proton LET is notoriously difficult to measure directly with only a very limited number of devices commercially available such as the tissue‐equivalent proportionality counter (TEPC), 19 silicon spectrometer, 20 or CR‐39 etch detectors 21 . Other authors have presented creative strategies for simultaneous proton dose and LET measurements such as the use of organic scintillators, 22 thermoluminescent dosimeters 23,24 (TLDs), Al 2 O 3 :C OSLD 25 detectors, and Gafchromic EBT3 films 26 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dual‐storage phosphor proton therapy dosimetry: Simultaneous quantification of dose and linear energy transfer

et al. 2021

View full text Add to dashboard Cite

To investigate the feasibility of using the high Z eff storage phosphor material BaFBrI:Eu 2+ in conjunction with the low Z eff storage phosphor material KCl:Eu 2+ for simultaneous proton dose and linear energy transfer (LET) measurements by (a) measuring the fundamental optical and dosimetric properties of BaFBrI:Eu 2+ , (b) evaluating its compatibility in being readout simultaneously with KCl:Eu 2+ dosimeters, and (c) modeling and validating its LET dependence under elevated proton LET irradiation. Methods: A commercial BaFBrI:Eu 2+ storage phosphor detector (Model ST-VI, Fujifilm) was characterized with energy dispersive x-ray spectroscopy (EDS) analysis to obtain its elemental composition. The dosimeters were irradiated using both a Mevion S250 proton therapy unit (at the center of a spread-out Bragg peak, SOBP) and a Varian Clinac iX linear accelerator with the latter being a low LET irradiation. The photostimulated luminescence (PSL) emission spectra, excitation spectra, and luminescent lifetimes of the detector were measured after proton and photon irradiations. Dosimetric properties including dose linearity, dose rate dependence, radiation hardness, temporal, and readout stabilities were studied using a laboratory optical reader after proton irradiations. In addition, its proton energy dependence was analytically modeled and experimentally validated by irradiating the detectors at various depths within the SOBP (Range: 15.0 g/ cm 2 , Modulation: 10.0 g/cm 2 ). Results: The active detector composition for the high Z eff storage phosphor detector was found to be BaFBr 0.85 I 0.15 :Eu 2+ . The BaFBr 0.85 I 0.15 :Eu 2+ material's excitation and emission spectra were in agreement under proton and photon irradiations, with peaks of 586 AE 1 nm and 400 AE 1 nm, respectively, with a full width at half maximum (FWHM) of 119 AE 3 nm and 30 AE 2 nm, respectively. As dosimeter response under photon irradiation is generally believed to be free from LET effect, these results suggest LET independence of charge storage center types resulted from ionizing radiations. There is sufficient spectral overlaps with KCl:Eu 2+ dosimeters allowing both dosimeters to be readout under equivalent readout conditions, that is, 594 nm stimulation and 420 nm detection wavelengths. Its PSL characteristic lifetime was found to be less than 5 microseconds which would make it suitable for fast 2D readout post irradiation. Its 420 nm emission band intensity was found to be linear up to 10 Gy absolute proton dose under the same irradiation conditions, dose rate independent, stable in time and under multiple readouts, and with high radiation hardness under cumulative proton dose histories up to 200 Gy as tested in this study. BaFBr 0.85 I 0.15 :Eu 2+ showed significant proton energy-dependent dose under-response in regions of high LET which could be modeled by stopping power ratio calculations with an accuracy of 3% in low LET regions and a distance-toagreement (DTA) of 1 mm in high LET regions (>5 keV/μm). Conclusion:We have proven the feasibi...

show abstract