Evaluation of an Analytical Anisotropic Dose Calculation Algorithm in a Heterogeneous Medium Using In Vivo Dosimetry for High-Energy Photon Beams

Document Type : Original Paper

Authors

Department of Physics, Faculty of Science, Laboratory of Theoretical Physics and Matte Radiation Interaction (LPTHIRM), Saad Dahlab University of Blida, Algeria

Abstract

Introduction: The calibration process is usually limited to the depth of maximum energy. This study aimed to determine the depth dose in a heterogeneous medium using diodes and to evaluate a dose calculation algorithm.
Material and Methods: Measurements were done at three depths (4, 8, and 12 cm) using ten QEDTM diodes on heterogeneous phantoms (HPH), composed of poly(methyl methacrylate) (PMMA) and expanded polystyrene, roughly simulating the rib cage. These phantoms were irradiated with 6-MV and 18-MV photon beams from a Varian linear accelerator by plans calculated by the Eclipse treatment planning system, equipped with the Anisotropic Analytical Algorithm (AAA). The calibration curves were drawn by considering several measurement points in depth by a graphite ionization chamber in the HPH. The diode calibration factor was taken from the curves via interpolation. The measured and calculated values were compared to evaluate the AAA.
Results: Depending on the depth, the deviations between the measurements and calculations predicted by the TPS remained less than 2%. Some measurements had an order of magnitude of nearly 3%. An average deviation of 1.13% was obtained for all measurements, with an average deviation of 0.66% and a standard deviation of 0.80%. The upper bound of the confidence interval was 1.41%.
Conclusion: The deviations obtained in this study remained within the recommended standard range for validation of a dose calculation algorithm in a heterogeneous medium. The calibration method based on dose profiles provided further information about the dose in a heterogeneous medium, based on a single diode reading. 

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Main Subjects

References

  1. Technical reports series N° Commissioning and quality assurance of computerized planning systems for radiation treatment of cancer. International Atomic Energy Agency, Vienna. 2004.
  2. Papanikolaou N, Battista JJ, Boyer AL, Kappas C, Klein E, Mackie TR, et al. Tissue inhomogeneity corrections for megavoltage photon beams. AAPM Task Group. 2004 Aug; 65:1-42.
  3. Engelsman M, Damen EM, Koken PW, van‘t Veld AA, van Ingen KM, Mijnheer BJ. Impact of simple tissue inhomogeneity correction algorithms on conformal radiotherapy of lung tumours. Radiotherapy and Oncology. 2001 Sep 1;60(3):299-309.
  4. Ekstrand KE, Barnes WH. Pitfalls in the use of high energy X rays to treat tumors in the lung. Int J Radiat Oncol Biol Phys. 1990; 18:249-52.
  5. Hunt MA, Desobry GE, Fowble B, Coia LR. Effect of low-density lateral interfaces on soft-tissue doses. Int J Radiat Oncol Biol Phys. 1997; 37:475-82.
  6. Kornelsen RO, Young ME. Changes in the dose-profile of a 10 MV xray beam within and beyond low density material. Med Phys. 1982; 9:114-6.
  7. Rice RK, Mijnheer BJ, Chin LM. Benchmark measurements for lung dose corrections for X-ray beams. Int J Radiat Oncol Biol Phys. 1988; 15:399-409.
  8. Yorke E, Harisiadis L, Wessels B, Aghdam H, Altemus R. Dosimetric considerations in radiation therapy of coin lesions of the lung. Int J Radiat Oncol Biol Phys. 1996; 34:481-7.
  9. Young ME, Kornelsen RO. Dose corrections for low-density tissue inhomogeneities and air channels for 10-MV x rays. Med Phys. 1983; 10:450-5.
  10. Leunens G, van Dam J, Dutreix A, Van Der Schueren E. Quality assurance in radiotherapy by in vivo dosimetry. Entrance dose measurements, a reliable procedure. Radiother. Oncol. 1990; 17: 141–
  11. Heukelom S, Lanson JH, Mijnheer BJ. Comparison of entrance and exit dose measurements using ionisation chambers and silicon diodes. Phys. Med. Biol. 1991; 36: 47–
  12. Essers M, Keus R, Lanson J, Mijnheer B. Dosimetric control of conformal treatment of parotid gland tumours. Radiother. Oncol. 1994; 32: 154–
  13. Van Dam J, Marinello G. Methods for in vivo dosimetry in external radiotherapy. Physics for clinical radiotherapy. ESTRO Booklet n. 1 (Garant). 1994.
  14. Luca Cozzi, Antonella Fogliata-Cozzi. Quality assurance in radiation oncology. A study of feasibility and impact on action levels of an in vivo dosimetry program during breast cancer irradiation. Radiotherapy and Oncology. 1998; 46: 29–
  15. Technical reports series N° Absorbed dose determination in external beam radiotherapy. An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water. International Atomic Energy Agency, Vienna, 2000.
  16. User’s Guide QEDTM Detector Model 1112 through 1116. Sun Nuclear corportation. Document 1112011. 2005.
  17. Shi J, Sanders TJ, Simon WE. Calculation of diode sensitivity as a function of accumulated electron beam dose. Med. Phys. 1995;22.
  18. Heukelom S, Lanson JH, Mijnheer B. In vivo dosimetry during pelvic treatment. Radiother. Oncol. 1992; 25: 111–
  19. Colussi VC, Beddar AS, Kinsella TJ, Sibata CH. In vivo dosimetry using a single diode for megavoltage photon beam radiotherapy: Implementation and response characterization. Journal of Applied Clinical Medical Physics. 2001 Sep;2(4):210-8.
  20. Alecu R, Alecu M, Ochran TG. A method to improve the effectiveness of diode in vivo dosimetry. Medical physics. 1998 May;25(5):746-9.
  21. Sievinen J, Ulmer W, Kaissl W. AAA photon dose calculation model in Eclipse. Palo Alto (CA): Varian Medical Systems. 2005;118:2894.
  22. Sievinen J, Ulmer W, Kaissl W. AAA photon dose calculation model in Eclipse. Palo Alto (CA): Varian Medical Systems. 2005;118: 2894.
  23. Aarup LR, Nahum AE, Zacharatou C, Juhler-Nottrup T, Knoos T, Nystrom H, et al. The effect of different lung densities on the accuracy of various radiotherapy dose calculation methods: implications for tumour coverage. Radiother Oncol. 2009; 91:405–
  24. Mijnheer B, Olszewska A, Fiorino C, Hartmann G, Knöös T, Rosenwald JC, et al. Quality assurance of treatment planning systems: practical examples for non-IMRT photon beams. Brussels: Estro; 2004.
  25. Soh RC, Tay GH, Lew WS, Lee JC. A depth dose study between AAA and AXB algorithm against Monte Carlo simulation using AIP CT of a 4D dataset from a moving phantom. Reports of Practical Oncology & Radiotherapy. 2018 Sep 1;23(5):413-24.
  26. Bragg CM, Conway J. Dosimetric verification of the anisotropic analytical algorithm for radiotherapy treatment planning. Radiotherapy and oncology. 2006 Dec 1;81(3):315-23.
  27. Tillikainen L, Helminen H, Torsti T, Siljamäki S, Alakuijala J, Pyyry J, et al. A 3D pencil-beam-based superposition algorithm for photon dose calculation in heterogeneous media. Physics in Medicine & Biology. 2008 Jun 26;53(14):3821.
  28. 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.
  29. Rønde HS, Hoffmann L. Validation of Varian's AAA algorithm with focus on lung treatments. Acta Oncologica. 2009 Jan 1;48(2):209-15.
  30. Kashmiri L. Chopra, Paul Leo, Christopher Kabat, Durg Vijay Rai, Jaiteerth S, et al. Evaluation of dose calculation accuracy of treatment planning systems in the presence of tissue heterogeneities. Ther Radiol Oncol. 2018; 2:28.
  31. Rana S, Rogers K. Dosimetric evaluation of Acuros XB dose calculation algorithm with measurements in predicting doses beyond different air gap thickness for smaller and larger field sizes. Journal of medical physics/Association of Medical Physicists of India. 2013 Jan;38(1):9.
  32. Rana S, Rogers K, Pokharel S, Lee T, Reed D, Biggs C. Acuros XB algorithm vs. anisotropic analytical algorithm: A dosimetric study using heterogeneous phantom and computed tomography (CT) data sets of esophageal cancer patients. 2013.
  33. Dubey S, Bagdare P, Kumar Ghosh S. Design and study of a heterogeneous cost effective thorax phantom for dosimetric evaluation of analytic anisotropic algorithm (AAA) and acuros XB algorithm (AXB). International Journal of Radiology & Radiation Therapy. 2020; 7(2).
  34. Mohamed SA, Hassan GS, Elshahat KM. Evaluation of Calculation Algorithms for photon Beam dose in Heterogeneous Medium. Global Journal of Physics Vol. 2015 Jun 18;1(1).
  35. Da Rosa LA, Cardoso SC, Campos LT, Alves VG, Batista DV, Facure A. Percentage depth dose evaluation in heterogeneous media using thermoluminescent dosimetry. Journal of applied clinical medical physics. 2010 Dec;11(1):117-27.
  36. Fogliata A, Nicolini G, Clivio A, Vanetti E, Cozzi L. Dosimetric evaluation of Acuros XB Advanced Dose Calculation algorithm in heterogeneous media. Radiation oncology. 2011 Dec;6(1):1-5.
  37. Zaman A, Kakakhel MB, Hussain A. A comparison of Monte Carlo, anisotropic analytical algorithm (AAA) and Acuros XB algorithms in assessing dosimetric perturbations during enhanced dynamic wedged radiotherapy deliveries in heterogeneous media. Journal of Radiotherapy in Practice. 2019 Mar 1;18(1):75-81.
  38. Kim YL, Suh TS, Choe BY, Choi BO, Chung JB, Lee JW, et al. Dose distribution evaluation of various dose calculation algorithms in inhomogeneous media. International Journal of Radiation Research. 2016 Oct 1;14(4):269.
  39. Singh N, Painuly NK, Chaudhari LN, Chairmadurai A, Verma T, Shrotiya D, et al. Evaluation of AAA and XVMC Algorithms for Dose Calculation in Lung Equivalent Heterogeneity in Photon Fields: A Comparison of Calculated Results with Measurements. J Biomed Phys Eng. 2018; 8(3).
  40. Robinson D. Inhomogeneity correction and the analytic anisotropic algorithm. Journal of clinical medical physics. 2008; 9(2).
  41. Gagné IM, Zavgorodni S. Evaluation of the analytical anisotropic algorithm in an extreme water–lung interface phantom using Monte Carlo dose calculations. Journal of Applied Clinical Medical Physics. 2007 Dec;8(1):33-46.
  42. Hedin E, Bäck A, Chakarova R. Impact of lung density on the lung dose estimation for radiotherapy of breast cancer. Physics and Imaging in Radiation Oncology. 2017 Jul 1;3:5-10.

 

Iranian Journal of Medical Physics
Volume 19, Issue 1
January and February 2022
Pages 22-30

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History

  • Receive Date: 03 March 2020
  • Revise Date: 29 May 2020
  • Accept Date: 19 June 2020

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