Evaluación de la constancia de la energía empleando un sistema de imagen portal
- Leticia Irazola Rosales 1
- Álvaro Perales Molina 1
- Borja Aguilar Redondo 1
- Luis Ramos García 1
- Benigno Barbés Fernández 1
- 1 Clínica Universidad de Navarra, Pamplona
ISSN: 1576-6632
Any de publicació: 2020
Volum: 21
Número: 1
Pàgines: 33-40
Tipus: Article
Altres publicacions en: Revista de Física Médica
Resum
Introduction: In the present work, we aimed to present an alternative methodology to the use of commercial devices for daily quality assurance of the linac energy in the clinic using the electronic portal-imaging device combined with a pair of cylindrical aluminum pieces. Methodology: With an external degradation of beam energy, we achieved a modification of around 2% (considered as clinically relevant) in the representative energy parameter (PDD20,10: ratio of dose percentage at 20 and 10 cm depths, respectively). The proposed methodology was then validated for the detection of this beam perturbation. Results: We observed that the methodology was able to distinguish the intentioned deviations performed in photon energy with a good reproducibility, obtaining threshold-warning levels. Conclusions: The new methodology allows to establish a warning in case of a deviation clinically relevant in beam energy quality with the only use of the portal-imaging system together with a couple of aluminium pieces. The system has demonstrated to be reliable as well as easy to implement without needing extra equipment.
Referències bibliogràfiques
- Pinza c, Lliso F. Control de Calidad en Aceleradores de Electrones para uso médico. Madrid SEFM;2009.
- Adreo P, Burns DT, Hohlfeld K, Huq MS, Kanai T, Laiano F, Smyth V and Vynkier S. IAEA TRS-398 Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry based on Standards of Absorbed Dose to Water. IAEA 2006.
- Klein EE, Hanley J, Bayouth J et al., Task Group 142 report: Quality assurance of medical accelerators. Med Phys 2009;36(9):4197-212.
- KutcherGJ, Coia L, Gillin M et al., Task Group 40: Comprehensive QA for Radiation Oncology. AAPM Report nº 46, April 1994.
- Thwaites DI, Mijnheer B, Mills JA. Quality assurance of external beam radiotherapy. Radiation oncology physics: a handbook for teachers and students. Vienna: International Atomic Energy Agency; 2005. 407-450.
- Mosleh-Shirazi MA, Rahimi S, Karbasi S. Medium-term sta- bility of the photon beam energy of an Elekta Compact TM linear accelerator based on daily measurements of beam quality. IrJ Med Phys;2016:12(4):230-5.
- True Beam Stability: Results After 6 Months https://www. wienkav.at/kav/kfj/91033454/physik/tb/tb_beam_stability. htm
- Binny D, Lancaster CM, Kairn T, Trapp JV, Crowe SB. Technical note: Monitoring daily QA3 constancy for routine quality assurance on linear accelerators.Phys Medica 2016;32(11):1479-87.
- Patallo S and García F. Uso del Sistema imagen portal electrónica iViewGT para control de calidad del haz de radiación de un acelerador lineal de uso clínico. Rev Cub Fis 2010;27(2B):251-6.
- BudgellGJ, Zhang R and Mackay RI. Daily monitoring of lin- ear accelerator beam parameters using an amorphous silicon EPID. Phys Med Biol 2007;52:1721-33.
- Ding A, Xing L and Han B. Development of an accurate EPID-based output measurement and dosimetric verification tool for electron beam therapy. Med Phys 2015;42:4190-8.
- Saleh Z, Tang X, Song Y et al., Can EPID based measurement replace traditional daily output QA on Megavoltage linac?. Med Phys 2016;43(6)P26.
- Wang y, Heaton R, Norrlinger B and Islam M. Quality assur- ance of electron beams using a Varian electronic portal imag- ing device. Phys Med Biol 2013;58:5461-75.
- Andersson P. Utilizing statistical process control analysis and EPID for routine QA of medical linear accelerators. MS Lund University 2011.
- Cilla S, Fidanzio A, Greco F, Sabatino D, Russo A, Gargiulo L, Azario L and Piermattei A. Correlation functions for ElektaaSiEPIDs used as transit dosimeter for open fields.J ApplClin Med Phys2010:12(1):218-33.
- Gao S, Balter PA, Rose M and Simon WE. A comparison of methods for monitoring photon beam energy constancy.J ApplClinMedPhys 2016;17(6):242-53.