High resolution 2D plastic scintillator detectors for radiotherapy departments

• Autorzy: Woźniak Grzegorz Z. , Kozłowska Beata

Identyfikatory

DOI

10.2478/pjmpe-2023-0011

• Języki publikacji: EN

Abstrakty

EN

Plastic scintillation detectors (PSD) have been developed for over four decades and are widely used in a variety of fields, but one can find relatively few reports of their clinical use compared to other dosimetric solutions. The inexpensive detector setup made of a Saint-Gobain BC-400 plastic scintillator and commercially available on the market CMOS-based DSLR Pentax camera was investigated. Build PSD detectors were irradiated with 6, 10 and 15 MV flattening filtered (FF) and 6 and 10 MV flattening filter free (FFF) photon beams using a clinical linear accelerator. Data were processed using Matlab software to remove background and artefacts. A comparison of the spatial resolution parameters to the Gafchromic EBT3 films was performed. Average dose difference between TPS and PSD was 1.1%. The measured spatial resolution was 0.29 mm, and it differed from the film by 1.1%. MTF50 for PSD was 0.57 mm higher than the Gafchromic film. Signal to dose fit function with an R-square equal to 0.999 was established. The standard deviation of mean pixels value for a series of measurements was below 0.1%, for variable dose rate dependence was below 0.6% and for different energies 1.1%. It was demonstrated that such a setup allows a satisfactory signal-to-dose dependence and provides high spatial resolution at an affordable price compared to a 2D ion chamber or a diode detector array. Moreover, PSDs are reusable and provide a simple readout compared to Gafchromic films commonly used in radiotherapy departments. Variable parameters of the camera allow to select signal values at the optimal level. The system presented excellent signal stability, high image resolution and a simple signal-to-dose relationship which encourages further work to investigate PSDs for use in radiation therapy departments.

Słowa kluczowe

EN

PSD; dosimetry; radiotherapy; plastic scintillation detectors; Gafchromic films

• Wydawca: Polskie Towarzystwo Fizyki Medycznej ; De Gruyter
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2023
• Tom: Vol. 29, Iss. 2
• Strony: 92--103
• Opis fizyczny: Bibliogr. 19 poz., rys., tab.

Twórcy

autor

Woźniak Grzegorz Z.

• Institute of Physics, University of Silesia in Katowice, Poland

autor

Kozłowska Beata

• Zakład Radioterapii, Katowickie Centrum Onkologii, Poland

Bibliografia

• 1. Podgorsak EB. Radiation Oncology Physics, A Handbook for Teachers and Students: IAEA; 2005.
• 2. Beddar AS, Mackie TR, Attix FH. Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: I. Physical characteristics and theoretical consideration. Physics in Medicine & Biology. 1992;37(10):1883-1900. https://doi.org/10.1088/0031-9155/37/10/006
• 3. Beddar AS, Mackie TR, Attix FH. Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: II. Properties and measurements. Physics in Medicine & Biology. 1992;37(10):1901-1913. https://doi.org/10.1088/0031-9155/37/10/007
• 4. Goulet M, Rilling M, Gingras L, Beddar S, Beaulieu L, Archambault L. Novel, full 3D scintillation dosimetry using a static plenoptic camera. Medical Physics. 2014;41(8):082101. https://doi.org/10.1118/1.4884036
• 5. Carrasco P, Jornet N, Jordi O, et al. Characterization of the Exradin W1 scintillator for use in radiotherapy. Medical Physics. 2015;42(1):297-304. https://doi.org/10.1118/1.4903757
• 6. Beddar AS, Beaulieu L. Scintillation Dosimetry (1st ed.).: CRC Press; 2016. https://doi.org/10.1201/9781315372655
• 7. Law SH, Suchowerska N, McKenzie DR, Fleming SC, Lin T. Transmission of Cerenkov radiation in optical fibers. Optics Letters. 2007;32(10):1205-1207. https://doi.org/10.1364/OL.32.001205
• 8. de Boer FS, Beddar SA, J R. Optical filtering and spectral measurements of radiation induced light in plastic scintillation dosimetry. Physics in Medicine & Biology. 1993;38(7):945-958. https://doi.org/10.1088/0031-9155/38/7/005
• 9. Clift MA, Johnston PN, Webb DV. A temporal method of avoiding the Cerenkov radiation generated in organic scintillator dosimeters by pulsed mega-voltage electron and photon beams. Physics in Medicine & Biology. 2002;47(8):1421-1433. https://doi.org/10.1088/0031-9155/47/8/313
• 10. Frelin AM, Fontbonne JM, Ban G, et al. Spectral discrimination of Cerenkov radiation in scintillating dosimeters. Medical Physics. 2005;32(9):3000-3006. https://doi.org/10.1118/1.2008487
• 11. Lambert J, Yin Y, McKenzie DR, Law S, Suchowerska N. Cerenkov-free scintillation dosimetry in external beam radiotherapy with an air core light guide. Physics in Medicine & Biology. 2008;53(11):3071-3080. https://doi.org/10.1088/0031-9155/53/11/021
• 12. Robertson D, Hui C, Archambault L, Mohan R, Beddar S. Optical artefact characterization and correction in volumetric scintillation dosimetry. Physics in Medicine & Biology. 2013;59(1):23-42. https://doi.org/10.1088/0031-9155/59/1/23
• 13. Brown TAD, Hogstrom KR, Alvarez D, II MKL, Ham K, Dugas JP. Dose-response curve of EBT, EBT2, and EBT3 radiochromic films to synchrotron-produced monochromatic x-ray beams. Medical Physics. 2012;39:7412-7417. https://doi.org/10.1118/1.4767770
• 14. Ashland. Gafchromic EBT2 self-developingfilm for radiotherapy dosimetry film. http://www.filmqapro.com/Documents/GafChromic_EBT-2_20101007.pdf
• 15. Devic S. Radiochromic film dosimetry: past, present, and future. Physica Medica. 2010;27(3):122-134. https://doi.org/10.1016/j.ejmp.2010.10.001
• 16. Devic S, Tomic N, Lewis D. Reference radiochromic film dosimetry: Review of technical aspects. Physica Medica. 2016;32(4):541-556. https://doi.org/10.1016/j.ejmp.2016.02.008
• 17. Micke A, Lewis DF, Yu X. Multichannel film dosimetry with nonuniformity correction. Medical Physics. 2011;38(8):2523-2534. https://doi.org/10.1118/1.3576105
• 18. Alfonso R, Andreo P, Capote R, et al. A new formalism for reference dosimetry of small and nonstandard fields. Medical Physics. 2008;35(11):5179-5186. https://doi.org/10.1118/1.3005481
• 19. Puysseleyr AD. Absorbed Dose in the Build-up Region in Modern Megavoltage Photon Radiotherapy: PhD Thesis; 2016. http://hdl.handle.net/1854/LU-7099984

Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).