Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
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Evaluation of Dose Volume and Radiobiological Indices by the Dose Calculation Grid Size in Nasopharyngeal Cancer VMAT

비 인두암 체적 조절 호형 방사선 치료의 선량 계산 격자 크기에 따른 선량 체적 지수와 방사선 생물학적 지수의 평가

  • Kang, Dong-Jin (Department of Radiation Oncology, Inje University Sanggye Paik Hospital) ;
  • Jung, Jae-Yong (Department of Radiation Oncology, Inje University Sanggye Paik Hospital) ;
  • Shin, Young-Joo (Department of Radiation Oncology, Inje University Sanggye Paik Hospital) ;
  • Min, Jung-Whan (Department of Radiological technology, Shingu University) ;
  • Shim, Jae-Goo (Department of Radiologic technology, Daegu Health College) ;
  • Park, So-Hyun (Department of Radiation Oncology, Jeju National University Hospital)
  • 강동진 (인제대학교 상계백병원 방사선종양학과) ;
  • 정재용 (인제대학교 상계백병원 방사선종양학과) ;
  • 신영주 (인제대학교 상계백병원 방사선종양학과) ;
  • 민정환 (신구대학교 방사선과) ;
  • 심재구 (대구보건대학교 방사선과) ;
  • 박소현 (제주대학교병원 방사선종양학과)
  • Received : 2020.06.08
  • Accepted : 2020.08.30
  • Published : 2020.08.31
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Abstract

The purpose of this study was to investigate the dose-volume indices and radiobiological indices according to the change in dose calculation grid size during the planning of nasopharyngeal cancer VMAT treatment. After performing the VMAT treatment plan using the 3.0 mm dose calculation grid size, dose calculation from 1.0 mm to 5.0 mm was performed repeatedly to obtain a dose volume histogram. The dose volume index and radiobiological index were evaluated using the obtained dose volume histogram. The smaller the dose calculation grid size, the smaller the mean dose for CTV and the larger the mean dose for PTV. For OAR of spinal cord, brain stem, lens and parotid gland, the mean dose did not show a significant difference according to the change in dose calculation grid size. The smaller the grid size, the higher the conformity of the dose distribution as the CI of the PTV increases. The CI and HI showed the best results at 3.0 mm. The smaller the dose calculation grid size, the higher the TCP of the PTV. The smaller the dose calculation grid size, the lower the NTCP of lens and parotid. As a result, when performing the nasopharynx cancer VMAT plan, it was found that the dose calculation grid size should be determined in consideration of dose volume index, radiobiological index, and dose calculation time. According to the results of various experiments, it was determined that it is desirable to apply a grid size of 2.0 - 3.0 mm.

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References

  1. Van Dyk J, Barnett RB, Cygler JE, Sharagge PC. Commissioning and quality assurance of treatment planning computers. Int J Radiat Oncol Biol Phys. 1993;26:261-73. https://doi.org/10.1016/0360-3016(93)90206-b
  2. Commissioning and quality assurance of computerized planning systems for radiation treatment of cancer. International Atomic Energy Agency. Vieena; 2004.
  3. Masi L, Casamassima F, Doro R, Francescon P. Quality assurance of volumetric modulated arc therapy: evaluation and comparison of different dosimetric systems. Med Phys. 2011;38(2):612-21. https://doi.org/10.1118/1.3533900
  4. Ren W, Sun C, Lu N, Xu Y, Han F, Liu YP, et al. Dosimetric comparison of intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy in patients with prostate cancer: A meta-analysis. J Appl Clin Med Phys. 2016;17(6):254-62. https://doi.org/10.1120/jacmp.v17i6.6464
  5. Quan EM, Li X, Li Y, Wang X, Kudchadker RJ, Johnson JL, et al. A comprehensive comparison of IMRT and VMAT plan quality for prostate cancer treatment. Int J Radiat Oncol Biol Phys. 2012;83(4):1169-78. https://doi.org/10.1016/j.ijrobp.2011.09.015
  6. Das IJ, Moskvin V, Johnstone PA. Analysis of Treatment Planning Time Among Systems and Planners for Intensity-Modulated Radiation Therapy. J Am Coll Radiol. 2009;6:514-17. https://doi.org/10.1016/j.jacr.2008.12.013
  7. Chung HT, Jin HS, Jatinder P, Suh TS, Kin SY. Dose Variations With Varying Calculation Grid Size in Head and Neck IMRT. Phys Med Biol. 2006;51(19):4841-56. https://doi.org/10.1088/0031-9155/51/19/008
  8. Dempsey JF, Romeijn HE, Li JG, Low DA, Palta JR. A Fourier analysis of the dose grid resolution required for accurate IMRT fluence map optimization. Med. Phys. 2005;32:380-8. https://doi.org/10.1118/1.1843354
  9. Srivastava SP, Cheng CW, Das IJ. The dosimetric and radiobiological impact of calculation grid size on head and neck IMRT. Pract Radiat Oncol. 2017;7:209-17. https://doi.org/10.1016/j.prro.2016.10.001
  10. Srivastava SP, Cheng CW, Das IJ. The effect of slice thickness on target and organs at risk vol- umes, dosimetric coverage and radiobiological impact in IMRT planning. Clin Transl Oncol 2016;18:469-79. https://doi.org/10.1007/s12094-015-1390-z
  11. Akino Y, Das IJ, Bartlett GK, Zhang H, Thompson E, Zook JE. Evaluation of superficial dosimetry between treatment planning system and measurement for several breast cancer treatment techniques. Med Phys. 2013;40(1):011714(1-6).
  12. Oncentra Master Plan physics and algorithm documentation, Nucletron, Netherlands; 2011.
  13. Park SH, Lee DS, Lee YH, Lee SR, Kim MJ, Suh TS. Physical and Biological Pretreatment Quality Assurance of the Head and Neck Cancer Plan with the Volumetric Modulated Arc Therapy. Journal of the Korean Physical Society. 2015;67:946-55. https://doi.org/10.3938/jkps.67.946
  14. Hiram A, Andrzej N. A free program for calculating EUD-based NTCP and TCP in external beam radiotherapy. Physica Medica. 2007;23:115-25. https://doi.org/10.1016/j.ejmp.2007.07.001
  15. Prescribing, Recording, and Reporting Photon Beam Therapy (Supplement to ICRU Report 50). International Commission on Radiation Units and Measurements (ICRU). Report 62: Journal of the ICRU Vol 7 No 2 (2007) Report 62.
  16. Feuvret L, NoNl G, Mazeron JJ, Bey P. Conformity index: A review. Int J Radiat Oncol Biol Phys 2006;64(2):333-42. https://doi.org/10.1016/j.ijrobp.2005.09.028
  17. Prescribing, Recording, and Reporting Photon-Beam Intensity-Modulated Radiation Therapy (IMRT). Journal of the ICRU Vol 10 No 1 (2010) Report 83.
  18. Emami B, Lyman J, Brown A, Cola L, Goitein M, Munzenrider JE, et al., Tolerance of normal tissue to therapeutic irradiation. Int. J. Radiat. Oncol. Biol. Phys. 1991;21:109-22.
  19. Brenner DJ. Dose, volume, and tumor-control predictions in radiotherapy. Int. J. Radiat. Oncol. Biol. Phys. 1993;26:171-9. https://doi.org/10.1016/0360-3016(93)90189-3
  20. Okunieff P, Morgan D, Niemierko A, Suit HD. Radiation dose-response of human tumors. Int. J. Radiat. Oncol. Biol. Phys. 1995;32(4):1227-37. https://doi.org/10.1016/0360-3016(94)00475-Z
  21. Kim YL, Chung JB, Lee JW, Shin YJ, Kang DJ, Jung JY. The Effect of MLC Leaf Motion Constraints on Plan Quality and Delivery Accuracy in VMAT. Journal of Radiological Science and Technology. 2019;42(3):217-22. https://doi.org/10.17946/JRST.2019.42.3.217
  22. Kang DJ, Jung JY, Shin YJ, Min JW, Kim YL, Yang HJ. Quality Assurance of Volumetric Monulated Arc Therapy Using the Dynalog Files. Journal of Radiological Science and Technology. 2016;19(4):577-85.