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Accuracy of In-Field and Out-Field Doses Calculated by Analytical Anisotropic and Pencil Beam Convolution Algorithms: A Dosimetric Study

Year 2023, , 97 - 104, 28.03.2023
https://doi.org/10.54287/gujsa.1240626

Abstract

Out-of-field doses may affect the formation of secondary cancers, especially in radiosensitive organs, in patients treated with radiotherapy. The aim of this study is to investigate the in-field dose and out-of-field dose accuracy of Eclipse's analytic anisotropic algorithm (AAA) and pencil beam convolution (PBC) algorithms using TLDs. A tissue equivalent phantom containing a total of 21 measurement points at a depth of 5 cm from the anterior and posterior was created. Using Eclipse AAA and PBC algorithms in TPS, 100 MU for AP/PA fields and 95 cm source-skin distance (SSD) were planned. In-field measurement points including isocenter were 3, 5, 7 and 11 points for 3x3, 5x5, 7x7 and 10x10 cm2, respectively. Measuring points outside the field edge were 38, 36, 34 and 30 points for 3x3, 5x5, 7x7 and 10x10 cm2, respectively. In-field point dose values calculated by TPS for different fields were compared with TLD doses measured at the same location. The difference between in-field dose estimation and TLD measurements of both algorithms was generally below 1%. The difference between TPS and TLD was found to be 4.41% for the 10x10 cm2 irradiation field, due to the field edge at a distance of 5 cm from the isocenter. As the field size decreased, the out-of-field dose calculation performance of the AAA and PBC algorithms was adversely affected. For the 10x10 cm2 irradiation field, the TLD measurements and the out-of-field point dose difference of the PBC algorithm were found to be 39.40%. This difference was at most 12.06% for the AAA algorithm. The Eclipse TPS is good at calculating the in-field dose but underestimates the off-field dose. In out-of-field dose calculation, the AAA algorithm gives more accurate results than the PBC algorithm. Additionally, the smaller the field size, the worse the outfield dose accuracy. The use of in vivo dosimeters is recommended in order to estimate the out-of-field dose with great accuracy in radiotherapy.

References

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  • Acun-Bucht, H., Tuncay, E., Darendeliler, E., & Kemikler, G. (2018) Absolute dose verification of static intensity modulated radiation therapy (IMRT) with ion chambers of various volumes and TLD detectors. Reports of Practical Oncology & Radiotherapy, 23(4), 242-250. doi:10.1016/j.rpor.2018.04.001
  • Alghamdi, S., & Tajaldeen, A. (2019). Evaluation of dose calculation algorithms using different density materials for in-field and out-of-field conditions. Experimental Oncology, 41(1), 46-52. doi:10.32471/exp-oncology.2312-8852.vol-41-no-1.12529
  • Bahreyni Toossi, M. T., Soleymanifard, S., Farhood, B., Mohebbi, S., & Davenport, D. (2018). Assessment of accuracy of out-of-field dose calculations by TiGRT treatment planning system in radiotherapy. Journal of Cancer Research and Therapeutics, 14(3), 634-639. doi:10.4103/0973-1482.176423
  • Bosse, C., Narayanasamy, G., Saenz, D., Myers, P., Kirby, N., Rasmussen, K., Mavroidis, P., Papanikolaou, N., & Stathakis, S. (2020). Dose Calculation Comparisons between Three Modern Treatment Planning Systems. Journal of Medical Physics, 45(3), 143-147. doi:10.4103/jmp.jmp_111_19
  • DePew, K. D., Ahmad, S., & Jin, H. (2018). Experimental Assessment of Proton Dose Calculation Accuracy in Small-Field Delivery Using a Mevion S250 Proton Therapy System. Journal of Medical Physics, 43(4), 221-229. doi:10.4103/jmp.jmp_33_18
  • Gul, O. V., Inan, G., & Basaran, H. (2021). Dosimetric comparison of different radiotherapy techniques to determine the absorbed fetal dose in pregnant patients with left-sided breast cancer. Arab Journal of Nuclear Sciences and Applications, 54(4), 94-101. doi:10.21608/ajnsa.2021.69536.1456
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  • Huang, J. Y., Followill, D. S., Wang, X. A., & Kry, S. F. (2013). Accuracy and sources of error of out-of field dose calculations by a commercial treatment planning system for intensity-modulated radiation therapy treatments. Journal of Applied Clinical Medical Physics, 14(2), 186-197. doi:10.1120/jacmp.v14i2.4139
  • Sánchez-Nieto, B., Medina-Ascanio, K. N., Rodríguez-Mongua, J. L., Doerner, E., & Espinoza, I. (2020). Study of out-of-field dose in photon radiotherapy: A commercial treatment planning system versus measurements and Monte Carlo simulations. Medical Physics, 47(9), 4616-4625. doi:10.1002/mp.14356
  • Shine, N. S., Paramu, R., Gopinath, M., Jaon Bos, R. C., & Jayadevan, P. M. (2019). Out-of-Field Dose Calculation by a Commercial Treatment Planning System and Comparison by Monte Carlo Simulation for Varian TrueBeam®. Journal of Medical Physics, 44(3),156-175. doi:10.4103/jmp.jmp_82_18
  • Wang, L., & Ding G. X. (2014). The accuracy of the out-of-field dose calculations using a model-based algorithm in a commercial treatment planning system. Physics in Medicine & Biology, 59(13), N113-28. doi:10.1088/0031-9155/59/13/n113
Year 2023, , 97 - 104, 28.03.2023
https://doi.org/10.54287/gujsa.1240626

Abstract

References

  • Abazarfard, M., Azadeh, P., & Mostaar, A. (2021). Dose calculation accuracy for photon small fields in treatment planning systems with comparison by Monte Carlo simulations. Polish Journal of Medical Physics and Engineering, 27(3), 181-190. doi:10.2478/pjmpe-2021-0022
  • Acun-Bucht, H., Tuncay, E., Darendeliler, E., & Kemikler, G. (2018) Absolute dose verification of static intensity modulated radiation therapy (IMRT) with ion chambers of various volumes and TLD detectors. Reports of Practical Oncology & Radiotherapy, 23(4), 242-250. doi:10.1016/j.rpor.2018.04.001
  • Alghamdi, S., & Tajaldeen, A. (2019). Evaluation of dose calculation algorithms using different density materials for in-field and out-of-field conditions. Experimental Oncology, 41(1), 46-52. doi:10.32471/exp-oncology.2312-8852.vol-41-no-1.12529
  • Bahreyni Toossi, M. T., Soleymanifard, S., Farhood, B., Mohebbi, S., & Davenport, D. (2018). Assessment of accuracy of out-of-field dose calculations by TiGRT treatment planning system in radiotherapy. Journal of Cancer Research and Therapeutics, 14(3), 634-639. doi:10.4103/0973-1482.176423
  • Bosse, C., Narayanasamy, G., Saenz, D., Myers, P., Kirby, N., Rasmussen, K., Mavroidis, P., Papanikolaou, N., & Stathakis, S. (2020). Dose Calculation Comparisons between Three Modern Treatment Planning Systems. Journal of Medical Physics, 45(3), 143-147. doi:10.4103/jmp.jmp_111_19
  • DePew, K. D., Ahmad, S., & Jin, H. (2018). Experimental Assessment of Proton Dose Calculation Accuracy in Small-Field Delivery Using a Mevion S250 Proton Therapy System. Journal of Medical Physics, 43(4), 221-229. doi:10.4103/jmp.jmp_33_18
  • Gul, O. V., Inan, G., & Basaran, H. (2021). Dosimetric comparison of different radiotherapy techniques to determine the absorbed fetal dose in pregnant patients with left-sided breast cancer. Arab Journal of Nuclear Sciences and Applications, 54(4), 94-101. doi:10.21608/ajnsa.2021.69536.1456
  • Howell, R. M., Scarboro, S. B., Kry, S. F., & Yaldo, D. Z. (2010). Accuracy of out-of-field dose calculations by a commercial treatment planning system. Physics in Medicine & Biology, 55(23), 6999-7008. doi:10.1088/0031-9155/55/23/S03
  • Huang, J. Y., Followill, D. S., Wang, X. A., & Kry, S. F. (2013). Accuracy and sources of error of out-of field dose calculations by a commercial treatment planning system for intensity-modulated radiation therapy treatments. Journal of Applied Clinical Medical Physics, 14(2), 186-197. doi:10.1120/jacmp.v14i2.4139
  • Sánchez-Nieto, B., Medina-Ascanio, K. N., Rodríguez-Mongua, J. L., Doerner, E., & Espinoza, I. (2020). Study of out-of-field dose in photon radiotherapy: A commercial treatment planning system versus measurements and Monte Carlo simulations. Medical Physics, 47(9), 4616-4625. doi:10.1002/mp.14356
  • Shine, N. S., Paramu, R., Gopinath, M., Jaon Bos, R. C., & Jayadevan, P. M. (2019). Out-of-Field Dose Calculation by a Commercial Treatment Planning System and Comparison by Monte Carlo Simulation for Varian TrueBeam®. Journal of Medical Physics, 44(3),156-175. doi:10.4103/jmp.jmp_82_18
  • Wang, L., & Ding G. X. (2014). The accuracy of the out-of-field dose calculations using a model-based algorithm in a commercial treatment planning system. Physics in Medicine & Biology, 59(13), N113-28. doi:10.1088/0031-9155/59/13/n113
There are 12 citations in total.

Details

Primary Language English
Journal Section Physics
Authors

Osman Vefa Gül 0000-0002-6773-3132

Publication Date March 28, 2023
Submission Date January 22, 2023
Published in Issue Year 2023

Cite

APA Gül, O. V. (2023). Accuracy of In-Field and Out-Field Doses Calculated by Analytical Anisotropic and Pencil Beam Convolution Algorithms: A Dosimetric Study. Gazi University Journal of Science Part A: Engineering and Innovation, 10(1), 97-104. https://doi.org/10.54287/gujsa.1240626