Diseo de un fantoma para auditoras dosimtricas remotas en braquiterapia de alta tasa de dosis / Design of a phantom for remote dosimetric audits in high dose rate brachyterapy

Gilli, Roco L. (2023) Diseo de un fantoma para auditoras dosimtricas remotas en braquiterapia de alta tasa de dosis / Design of a phantom for remote dosimetric audits in high dose rate brachyterapy. Master in Medical Physics, Universidad Nacional de Cuyo, Instituto Balseiro.

[img]
Preview
PDF (Tesis)
Spanish
12Mb

Abstract in Spanish

Una de las herramientas esenciales de un programa de QA en radioterapia, que contribuye a garantizar exactitud en la dosimetra de sus tratamientos, es el uso de auditorias dosimtricas. El objetivo de este trabajo fue evaluar la factibilidad de implementar un programa de auditora dosimtrica postal de nivel II en braquiterapia de alta tasa de dosis (BT HDR) con fuente de 192"Ir por primera vez en Argentina, basando la dosimetra en el uso de luminiscencia pticamente estimulada (OSL). Para esto, se dise y construy un fantoma solido en PMMA de 80x140x80 mm"3 con dos canales para introducir la fuente y una ranura para colocar un dosmetro OSL nanoDot. El diseo mostr ser resistente a envos por correo postal, prctico, porttil y econmico. Para medir la dosis, se caracteriz y calibr un lote de dosmetros con el equipo Gammamed Plus iX, el cual aloja una fuente de 192"Ir. Se determinaron factores de influencia en el clculo de dosis propios de los OSLDs, y se analizaron posibles situaciones fuera del protocolo propuesto. Posteriormente, se implement un estudio piloto de auditora dosimtrica en colaboracin con 3 centros de RT de Argentina, para lo cual se desarroll un protocolo con instrucciones de planificacin e irradiacin, una hoja de trabajo y una encuesta para evaluar la calidad del programa propuesto, que se enviaron junto con el fantoma y los dosmetros. Como instancia final, se confeccion un informe con los resultados obtenidos, el cual fue presentado al fsico mdico responsable de realizar la medicin. Los resultados de la caracterizacin de los OSLD fueron muy satisfactorios, estando todos los factores de influencia dentro de lmites publicados internacionalmente. La incertidumbre para el clculo de dosis con el sistema dosimtrico propuesto fue del 4% con un nivel de confianza del 95 %. A partir de este valor se estableci como nivel de aceptacin optimo aquellas desviaciones porcentuales entre la dosis reportada por el TPS del centro y la dosis medida con OSLD, menores al 4 %; y aceptables, aquellas desviaciones entre el 4% y 5 %. En este contexto, los resultados obtenidos en los 3 centros se encontraron dentro del limite optimo, independientemente del equipo HDR auditado. Asimismo, a travs de la encuesta, los centros indicaron sensaciones positivas hacia el proyecto, destacando la facilidad de uso del fantoma y la claridad de la instrucciones tanto para planificacin como para irradiacin. Como conclusin, en esta primera experiencia se obtuvieron resultados muy alentadores, tanto en el uso de los OSLDs como dosmetros para 192"Ir, como del estudio piloto en s, que servira de base para un futuro programa oficial de auditoras dosimtricas en BT HDR por primera vez en nuestro pas.

Abstract in English

One of the essential tools in a QA program in radiotherapy, contributing to ensuring accuracy in the dosimetry of treatments, is the use of dosimetric audits. The objective of this work was to evaluate the feasibility of implementing a level II postal dosimetric audit program in high-dose-rate brachytherapy (HDR BT) with a 192"Ir source for the first time in Argentina, basing dosimetry on the use of optically stimulated luminescence (OSL). For this purpose, a solid PMMA phantom of dimensions 80x140x80 mm"3 was designed and constructed with two channels to insert the source and a slot to place an OSL nanoDot dosimeter. The design proved to be resistant to postal shipments, practical, portable, and cost-effective. To measure the dose, a batch of dosimeters was characterized and calibrated with the Gammamed Plus iX equipment, which houses a 192"Ir source. Influence factors in the dose calculation specific to OSLDs were determined, and potential deviations from the proposed protocol were analyzed. Subsequently, a pilot dosimetric audit study was implemented in collaboration with three radiotherapy centers in Argentina. For this, a protocol with planning and irradiation instructions, a worksheet, and a survey to assess the quality of the proposed program were developed and sent along with the phantom and dosimeters. As a final step, a report with the obtained results was prepared and presented to the medical physicist responsible for carrying out the measurement. The results of the OSLD characterization were very satisfactory, with all influencing factors falling within internationally published limits. The uncertainty for dose calculation with the proposed dosimetric system was 4% with a 95% confidence level. Based on this value, deviations between the dose reported by the center’s TPS and the dose measured with OSLDs were established as optimal if they were less than 4%, and acceptable if they fell between 4% and 5%. In this context, the results obtained in all three centers were within the optimal limit, regardless of the audited HDR equipment. Additionally, through the survey, the centers expressed positive feedback about the project, highlighting the ease of use of the phantom and the clarity of instructions for both planning and irradiation. In conclusion, in this first experience, very encouraging results were obtained, both in the use of OSLDs as dosimeters for 192"Ir, and in the pilot study itself, which would serve as the basis for a future official program of dosimetric audits in BT HDR for the first time in our country.

Item Type:Thesis (Master in Medical Physics)
Keywords:Audits; Auditora; Brachytherapy; Braquiterapia; [Phantom; Fantoma]
References:[1] OMS. Cancer. Https://www.who.int/es/news-room/fact-sheets/detail/cancer (2022). 1 [2] Organization, W. H. Global Cancer Observatory. Https://gco.iarc.fr/. 1, 2 [3] IAEA. Radiotherapy in cancer care: Facing the global challenge. Vienna, Austria: International Atomic Energy Agency, 2017. 1 [4] Lim, Y. K., Kim, D. Brachytherapy: A Comprehensive Review. Med. Phys., 32(2), 25–39, 2021. URL https://doi.org/10.14316/pmp.2021.32.2.25. 2, 23 [5] Otter, S. J., Stewart, A. J., Devlin, P. M. Modern Brachytherapy. Hematology/ Oncology Clinics of North America, 33, 1011–1025, 2019. URL https: //doi.org/10.1016/j.hoc.2019.08.011. 2 [6] Organization, W. H. Radiotherapy risk profile. Hematology/Oncology Clinics of North America, 2008. 2 [7] Clark, C., Aird, E., Bolton, S., Miles, E., Nisbet, A., Snaith, J., et al. Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials. Br J Radiol, pags. 1–13, 2015. 2 [8] OIEA. Aspectos fısicos de la garantıa de calidad en radioterapia: Protocolo de control de calidad, Vienna, 2000. 2, 48 [9] Organization, W. H. Quality assurance in radiotherapy, Geneva, 1998. URL https://apps.who.int/iris/handle/10665/40423. 3 [10] Pujades-Claumarchirant, M. C., Candela-Juan, C., Oliver-Ca˜namas, L., Angela Soriano-Cruz, Rovira-Escutia, J. J., Ballester-Pallares, F. Estudio piloto de una auditorıa postal dosimetrica para radioterapia en condiciones de referencia. Rev Fis Med, 23(1), 27–34, 2022. URL https://doi.org/10.37004/sefm/2022.23. 1.002. 3, 12 [11] Dunn, L., Lye, J., Kenny, J., Lehmann, J., Williams, I., Kron, T. Commissioning of optically stimulated luminescence dosimeters for use in radiotherapy. Radiation Measurements, 51-52, 31–39, 2013. URL http://dx.doi.org/10.1016/j. radmeas.2013.01.012. 3, 35, 40, 53, 56 [12] Oliver-Ca˜namas, L., Vijande, J., Candela-Juan, C., Gimeno-Olmos, J., Pujades- Claumarchirant, C., Rovira-Escutia, J. J., et al. A User-Friendly System for Mailed Dosimetric Audits of 192Ir or 60Co HDR Brachytherapy Sources. Cancers, 15, 1–14, 2023. URL https://doi.org/10.3390/cancers15092484. 3, 63 [13] IAEA. DAN (Dosimetry Audit Networks), 2023. URL https:// dosimetry-audit-networks.iaea.org/Home/AuditAvailability. 3 [14] Lopez, M. A. Tratamientos con braquiterapia. Aran Ediciones, 2014. 7, 8 [15] Podgorsak, E. Radiation Oncology Physics: A Handbook for Teachers and Students. International Atomic Energy Agency, Vienna, 2005. 7, 9, 11, 21, 22 [16] Chargari, C., Deutsch, E., Blanchard, P., Gouy, S., Martelli, H., Guerin, F., et al. Brachytherapy: An Overview for Clinicians. Cancer Journal for Clinicians, 0(0), 1–16, 2019. URL https://doi.org/10.3322/caac.21578. 8 [17] Academy, B. Braquiterapia: radioterapia especıfica de alta precision, 2014. 8 [18] Venselaar, J. L. M., Baltas, D., Meigooni, A. S., Hoskin, P. J. Comprehensive Brachytherapy: Physical and Clinical Aspects. Taylor & Francis Group, LLC, 2013. 9, 26 [19] Perez-Calatayud, J., Andrassy, M., Niatsetsky, Y. Co-60 frente a Ir-192 en braquiterapia de alta tasa de dosis: comparacion cientıfica y tecnica. Revista De Fısica Medica, 13(2), 125–130, 2012. URL https://revistadefisicamedica. es/index.php/rfm/article/view/8. 9 [20] IAEA. Live Chart of Nuclides. URL https://www-nds.iaea.org/relnsd/ vcharthtml/VChartHTML.html. 9 [21] Kubo, H. D., Glasgow, G. P., Pethel, T. D., Thomadsen, B. R., Williamson, J. F. High dose-rate brachytherapy treatment delivery: Report of the AAPM Radiation Therapy Committee Task Group No. 59. Medical Physics, 25(4), 375–403, 1998. 9, 10 [22] Nag, S. High Dose Rate Brachytherapy: Its Clinical Applications and Treatment Guidelines. Technology in Cancer Research and Treatment, 3(3), 269–287, 2004. 10 [23] Rivard, M. J., Coursey, B. M., DeWerd, L. A., Hanson, W. F., Huq, M. S., Ibbott, G. S., et al. Update of AAPM Task Group No. 43 Report: A revised AAPM protocol for brachytherapy dose calculations. Medical Physics, 31(3), 633–674, 2004. 11 [24] Clark, C. H., Jornet, N., Muren, L. P. The role of dosimetry audit in achieving high quality radiotherapy. Physics and Imaging in Radiation Oncology 5, pags. 85–87, 2018. URL https://doi.org/10.1016/j.phro.2018.03.009. 11 [25] Izewska, J., Lechner, W.,Wesolowska, P. Global availability of dosimetry audits in radiotherapy: The IAEA dosimetry audit networks database. Physics and Imaging in Radiation Oncology 5, pags. 1–4, 2018. URL https://doi.org/10.1016/j. phro.2017.12.002. 11 [26] Lye, J., Kenny, J., Lehmann, J., Dunn, L., Kron, T., Alves, A., et al. A 2D ion chamber array audit of wedged and asymmetric fields in an inhomogeneous lung phantom. Med. Phys., 41(10), 1–11, 2014. URL http://dx.doi.org/10.1118/ 1.4896097. 11, 13 [27] IAEA. Standards and codes of practice in medical radiation dosimetry, Volume 2. Vienna, Austria: International Atomic Energy Agency, 2003. 12, 13 [28] OIEA. Aspectos fısicos de la garantıa de calidad en radioterapia: Protocolo de control de calidad. Vienna, Austria: Organismo Internacional de Energıa Atomia, 2000. 12 [29] Yukihara, E. G., McKeever, S. W. S. Optically stimulated luminescence (OSL) dosimetry in medicine. Phys. Med. Biol., 53, 351–379, 2008. URL http://dx. doi.org/10.1088/0031-9155/53/20/R01. 12, 16, 18 [30] Palmer, A., Bradley, D. A., Nisbet, A. Review article: Dosimetric audit in brachytherapy. Br J Radiol, pags. 1–10, 2014. URL http://dx.doi.org/10. 1259/bjr.20140105. 14 [31] P, G., J., I. An IAEA survey of dosimetry audit networks for radiotherapy. SSDL Newsletter No. 61, pags. 23–27, 2013. URL http://www-pub.iaea.org/MTCD/ Publications/PDF/Newsletters/SSDL-61.pdf. 14 [32] Casey, K. E., Alvarez, P., Kry, S. F., Howell, R. M., Lawyer, A., Followil, D. Development and implementation of a remote audit tool for high dose rate (HDR) Ir-192 brachytherapy using optically stimulated luminescence dosimetry. Med. Phys., 40(11), 1–8, 2013. URL http://dx.doi.org/10.1118/1.4824915. 14, 48, 63 [33] Kry, S. F., Alvarez, P., Cygler, J. E., DeWerd, L. A., Howell, R. M., Meeks, S., et al. AAPM TG 191: Clinical use of luminescent dosimeters: TLDs and OSLDs. Med. Phys. 47 (2), 2020. 15, 16, 18, 19, 20, 21, 39, 56, 58, 63 [34] Casey, K. Development and Implementation of a remote audit tool for high dose rate (HDR) 192Ir brachytherapy using optically stimulated luminescence dosimetry. Tesis de grado en Maestrıa en Ciencias, University of Texas; supervisada por Ph.D. David Followill, 2012. 15, 17 [35] Bhatt, B. C. Thermoluminescence, optically stimulated luminescence and radiophotoluminescence dosimetry: An overall perspective. Radiat Prot Environ, 34, 6–16, 2011. 15 [36] Arnez, E. M. Dosimetrıa in vivo con el uso de detectores OSLD nanoDot en tomograf ıa computada multidetector cardıaca. Maestrıa en Fısica Medica. Instituto Balseiro, 2021. 15, 19 [37] Yukihara, E. G., Yoshimura, E. M., Lindstrom, T. D., Ahmad, S., Taylor, K. K., Mardirossian, G. High-precision dosimetry for radiotherapy using the optically stimulated luminescence technique and thin Al2O3:C dosimeters. Phys. Med. Biol., 50, 5619–5628, 2005. URL http://dx.doi.org/10.1088/0031-9155/50/ 23/014. 17, 59 [38] Yukihara, E. G., Yoshimura, E. M., Lindstrom, T. D., Ahmad, S., Taylor, K. K., Mardirossian, G. Characterization of optically stimulated luminescent dosimeters, OSLDs, for clinical dosimetric measurements, journal = Medical Physics. 34, 4594–4604, 2007. URL http://dx.doi.org/10.1118/1.2804555. 17, 20, 40, 46, 56, 58, 59 [39] Lopez, J. A. R. Dosimetrıa in vivo con el uso de OSL nanoDot en radioterapia con intensidad modulada. Maestrıa en Fısica Medica. Instituto Balseiro, 2019. 17, 35, 40, 46, 57 [40] IAEA. Development of Procedures for In Vivo Dosimetry in Radiotherapy. Human Health Reports No. 8. Vienna, Austria: International Atomic Energy Agency, 2013. 18 [41] JCGM. Evaluation of measurement data—Guide to the expression of uncertainty in measurement, 2008. 22 [42] Taylor, B. N., Kuyatt, C. E. Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results. . National Institute of Standards and Technology, Technical Note 1297, 1994 Edition. 22, 23 [43] Granero, D., Perez-Calatayud, J., Pujades-Claumarchirant, M., Ballester, F., Melhus, C. S., Rivard, M. J. Equivalent phantom sizes and shapes for brachytherapy dosimetric studies of Ir 192 and Cs 137. Medical Physics, 35(11), 4872–4877, 2008. URL http://dx.doi.org/10.1118/1.2982140. 26 [44] NIST. NIST Standard Reference Database 126, 2004. URL https://dx.doi. org/10.18434/T4D01F. 27, 44 [45] 38, I. R. Dose and Volume Specification for Reporting Intracavitary Therapy in Gynecology, 1985. 29 [46] Landauer. Manual de usuario microStar version 4.3, 2012. URL https://www. landauer.com/. 37 [47] Venselaar, J., Perez-Calatayud, J. A PRACTICAL GUIDE TO QUALITY CONTROL OF BRACHYTHERAPY EQUIPMENT. ESTRO Booklet No. 8, 2004. URL http://dx.doi.org/10.1118/1.2982140. 38 [48] Gonzales, V. E. Dosimetrıa in vivo con el uso de OSL nanoDot. Maestrıa en Fısica Medica. Instituto Balseiro, 2016. 40, 57 [49] Bondel, S., Ravikumar, M., Supe, S. S., Reddy, B. R. Calibration of 192Ir high dose rate brachytherapy source using different calibration procedures. Reports of practical oncology and radiotherapy, 19(3), 151–156, 2014. URL http://dx.doi. org/10.1016/j.rpor.2013.07.014. 44 [50] BALTAS, D., KONSTANTINA GERAMANI, D. I., GEORGIOS T. IOANNIDIS, D. I., KIRSTEN HIERHOLZ, I., BERND ROGGE, I., CHRISTOS KOLOTAS, M., et al. COMPARISON OF CALIBRATION PROCEDURES FOR 192IR HIGH-DOS RATE BRACHYTHERAPY SOURCES. Int. J. Radiation Oncology Biol. Phys., 43(3), 653–661, 1999. 44 [51] Haworth, A., Wilfert, L., Butler, D., Ebert, M. A., Todd, S., Bucci, J., et al. Australasian brachytherapy audit: Results of the ‘end-to-end’ dosimetry pilot study. Journal of Medical Imaging and Radiation Oncology, 57, 490–498, 2013. URL doi:10.1111/1754-9485.12042. 48 [52] Bassi, S., Berrigan, L., Zuchora, A., Fahy, L., Moore, M. End-to-end dosimetric audit: A novel procedure developed for Irish HDR brachytherapy centres. Physica Medica, 80, 221–229, 2020. URL https://doi.org/10.1016/j.ejmp.2020.10. 005. 48 [53] Roue, A., Venselaar, J. L., Ferreira, I. H., Bridier, A., Dam, J. V. Development of a TLD mailed system for remote dosimetry audit for 192Ir HDR and PDR sources Radiotherapy and Oncology, 83, 86–93, 2007. URL doi:10.1016/j.radonc.2007. 02.011. 48 [54] Ochoa, R., Gomez, F., Ferreira, I. H., Gutt, F., de Almeida, C. E. Design of a phantom for the quality control of high dose rate 192Ir source used in brachytherapy. Radiotherapy and Oncology, 82, 222–228, 2007. URL doi: 10.1016/j.radonc.2007.01.005. 48 [55] Landauer. nanoDot™ Dosimeter, 2019. URL landauer.com. 55 [56] Ruiz, A. V. Caracterizacion y puesta en servicio de un sistema dosimetrico basado en OSLD para auditorıas en radioterapia. Maestrıa en Fısica Medica. Instituto Balseiro, 2021. 58 [57] Nath, R., Anderson, L. L., Meli, J. A., Olch, A. J., Stitt, J. A., Williamson, J. F. Code of practice for brachytherapy physics: Report of the AAPM Radiation Therapy Committee Task Group No. 56. Medical Physics, 24 (10), 1557–1598, 1997. 62
Subjects:Medicine > Fsica mdica
Medicine > Dosimetry
Divisions:FUESMEN
ID Code:1229
Deposited By:Marisa G. Velazco Aldao
Deposited On:18 Mar 2024 12:25
Last Modified:18 Mar 2024 12:25

Repository Staff Only: item control page