Measurements of Photon Beam Flattening Filter Using an Anisotropic Analytical Algorithm and Electron Beam Employing Electron Monte Carlo

Document Type : Original Paper


1 Nuclear reactor, nuclear security and environment group, Physics Department, Faculty of Sciences, Mohamed V University, Rabat, Morocco & Sheikh Khalifa Ibn Zaid Hospital

2 Nuclear reactor, nuclear security and environment group, Physics Department, Faculty of Sciences, Mohamed V University, Rabat, Morocco

3 Physics Department, Faculty of sciences, Mohamed V university, Rabat, Morocco

4 Physics Department, Faculty of Science, Mohammed V University, Rabat, Morocco

5 Physics Department,Faculty of sciences, Mohamed V university, Rabat, Morocco.

6 Laboratory of technology and medical science, unity of biomedical instrumentation and medical physics, Higher Institute of Health Sciences; University Hassan I.


Introduction: This study aimed to report the measurement of photon and electron beams to configure the Analytical Anisotropic Algorithm and Electron Monte Carlo used in clinical treatment.
Material and Methods: All measurements were performed in a large water phantom using a 3-dimensional scanning system (PTW, Germany). For photon beams, the data were measured with a 0.125cc cylindrical chamber. For electron, the data were performed with a Roos chamber.
Results: In photon beams, flatness and symmetry for reference field size 10×10cm2 were within the tolerance intervals. Flatness were 0.79% and 1.55% for X6MV and X18MV, respectively. Symmetry were 0.57 and 0.25 for X6MV and X18MV, respectively. The output factor vary between 0.83 and 1.11 for X6MV. Moreover, it varies between 0.74 and 1.09 for X18MV. The leaf transmission factors were 0.97% for X6MV and1.14% for X18MV. The DLG were 1.31 and 1.34 for X6MV and X18MV, respectively. For electron beams, the quality index R50 for applicator 15×15cm2 were in the tolerance. Maximum depth dose for 6, 9, 12, 16 and 20MeV were 1.2, 1.9, 2.7, 2.99 and 2.4cm, respectively. Bremsstrahlung tail were 6MeV–2.86cm, 9MeV–4.32cm, 12MeV–5.96cm, 16MeV–7.93cm, and 20MeV–10.08cm per energy levels.
Conclusion: The obtained results and international recommendations were in a good agrement


Main Subjects

  1. References


    1. Ulmer W, Harder D. A triple Gaussian pencil beam model for photon beam treatment planning. Zeitschrift für medizinische Physik. 1995 Jan 1;5(1):25-30.
    2. Ulmer W, Harder D. Applications of a triple Gaussian pencil beam model for photon beam treatment planning. Zeitschrift für Medizinische Physik. 1996 Jan 1;6(2):68-74.
    3. Ulmer W, Kaissl W. The inverse problem of a Gaussian convolution and its application to the finite size of the measurement chambers/detectors in photon and proton dosimetry. Physics in Medicine & Biology. 2003 Mar 5;48(6):707-27.
    4. Neuenschwander H, Mackie TR, Reckwerdt PJ. MMC-a high-performance Monte Carlo code for electron beam treatment planning. Physics in Medicine & Biology. 1995 Apr;40(4):543-74.
    5. Fogliata A, Nicolini G, Vanetti E, Clivio A, Cozzi L. Dosimetric validation of the anisotropic analytical algorithm for photon dose calculation: fundamental characterization in water. Physics in Medicine & Biology. 2006 Feb 21;51(6):1421-38.
    6. Ulmer W, Pyyry J, Kaissl W. A 3D photon superposition/convolution algorithm and its foundation on results of Monte Carlo calculations. Physics in Medicine & Biology. 2005 Apr 6;50(8):1767-90.
    7. Van Esch A, Tillikainen L, Pyykkonen J, Tenhunen M, Helminen H, Siljamäki S, et al. Testing of the analytical anisotropic algorithm for photon dose calculation. Medical physics. 2006 Nov;33(11):4130-48.
    8. Sievinen J,Ulmer W, Kaissl W. AAA photon dose calculation model in Eclipse. Palo Alto (CA): Varian Medical Systems. 2005.
    9. Arunkumar T, Varatharaj C, Ravikumar M, Sathiyan S,Shwetha B. Commissioning and validation of the electron Monte Carlo dose calculation at extended source to surface distance from a medical linear accelerator.International Journal of Medical Research and Review. 2016.
    10. Yang X, Lasio G, Zhou J, Lin M, Yi B, Guerrero M. Commissioning of Electron Monte Carlo in Eclipse Treatment Planning System for TrueBeam. Med. Phys.2014; 41:362-6.
    11. Antolak JA, Bieda MS, Hogstrom KR. A Monte Carlo method for commissioning electron beams. InThe Use of Computers in Radiation Therapy. Springer, Berlin, Heidelberg. 2000 ; 449-51.
    12. Das IJ, Cheng CW, Watts RJ, Ahnesjö A, Gibbons J, Li XA, et al. Accelerator beam data commissioning equipment and procedures: report of the TG‐106 of the Therapy Physics Committee of the AAPM. Medical physics. 2008 Sep 1;35(9):4186-215.
    13. Aletti P, Bey P, Chauvel P, Chavaudra J, Costa A, Donnareix D, et al. Recommendations for a quality assurance programme in external radiotherapy. 1995;2.
    14. Mayilvaganan A, Athiyaman H, Chougule A. Analysis of Accuracy of Interpolation Methods in Estimating the Output Factors for Square Fields in Medical Linear Accelerator. Iranian Journal of Medical Physics. 2017;14(2):75-86.
    15. Varadharajan E, Ramasubramanian V. Commissioning and Acceptance Testing of the existing linear accelerator upgraded to volumetric modulated arc therapy. Reports of Practical Oncology & Radiotherapy. 2013 Sep 1;18(5):286-97.
    16. Szpala S, Cao F, Kohli K. On using the dosimetric leaf gap to model the rounded leaf ends in VMAT/RapidArc plans. Journal of applied clinical medical physics. 2014 Mar 1;15(2):67-84.
    17. Mullins J, DeBlois F, Syme A. Experimental characterization of the dosimetric leaf gap. Biomedical Physics & Engineering Express. 2016 Dec 16;2(6):065013.
    18. IAEA.Absorbed Dose Determination in External Beam Radiotherapy. IAEA Technical Reports Series No. 398. 2000.