용적변조회전 방사선치료 시 Set-up 오차에 따른 선량 전달 정확성의 평가

Assessment of Dose Delivery Accuracy with Set-up Error for VMAT

  • 하광은 (을지대학교병원 방사선종양학과) ;
  • 나권우 (신한대학교 방사선학과) ;
  • 이주훈 (신한대학교 방사선학과) ;
  • 박성아 (신한대학교 방사선학과) ;
  • 김상현 (신한대학교 방사선학과)
  • Ha, Gwang-Eun (Department of Radiation Oncology, EulJi Hospital) ;
  • Na, Kwon-Ou (Department of Radiological Science, Shinhan University) ;
  • Lee, Ju-Hun (Department of Radiological Science, Shinhan University) ;
  • Park, Sung-Ah (Department of Radiological Science, Shinhan University) ;
  • Kim, Sang-Hyun (Department of Radiological Science, Shinhan University)
  • 투고 : 2018.01.17
  • 심사 : 2018.03.04
  • 발행 : 2018.03.31

초록

In order to investigate the effect of set-up error on the dose delivery, this study evaluates the accuracy of dose delivery due to set-up error by applying a virtual brain tumor treatment plan using volumetric modulated rotational radiation therapy (VMAT). After obtaining a cross-sectional image with a CT device using Head Phantom, a treatment planning program was used to establish a VMAT treatment plan. Based on the treatment plan established, DQA was performed to assess the difference in dose delivery accuracy with set-up error. When the distance was changed to 7 mm with a distance of 1 mm on the basis of the measured value of 0 in the direction of Lat. and Vrt, a comparison was performed by deriving the average after 5 measurements each using a three dimensional array detector. We applied a virtual brain tumor treatment plan using VMAT. In the absence of set-up error, the measured values were 96.8%, 96.4%, 96.2% in Lat. ${\pm}1mm$, 96.2%, 95.9% in Lat. ${\pm}2mm$, 95.4%, 95.2% in Lat. ${\pm}3mm$, 92.0%, 90.1% in Lat. ${\pm}4mm$, 86.9%, 83.7% in Lat. ${\pm}5mm$, 85.6%, 80.3% in Lat. ${\pm}6mm$, 75.2%, 79.5% in Lat. ${\pm}7mm$, respectively. 96.1%, 96.1% in Vrt. ${\pm}1mm$, 95.9%, 95.7% in Vrt. ${\pm}2mm$, 95.1%, 95.1% in Vrt. ${\pm}3mm$, 91.4%, 91.5% in Vrt. ${\pm}4mm$, 88.6%, 88.3% in Vrt. ${\pm}5mm$, 83.1%, 85.6% in Vrt. ${\pm}6mm$, 79.1%, 77.2% in Vrt. ${\pm}7mm$ respectively. As the lateral and vertical error increases, the accuracy of the dose delivery decreases. In order to improve the accuracy of the dose delivery during VMAT treatment, we should try to reduce the error through accurate posture and appropriate image induction.

키워드

참고문헌

  1. Bak J, Jeong K, Keum KC and Park SW. 2006. On-line Image Guided Radiation Therapy using Cone-beam CT (CBCT). J. Korean. Soc. Ther. Radiol. Oncol. 24(3):294-299.
  2. Bruno S and Aris T. 2006. Clinical application of image-guided radiotherapy, IGRT (on the Varian OBI platform). Cancer Radioth. 10(5):252-257. https://doi.org/10.1016/j.canrad.2006.05.012
  3. Francisco CH and Silvia VC 2011. A Probability Approach to the Study on Uncertainty Effects on Gamma Index Evaluations in Radiation Therapy. Int. J. Comput. Math. 2011(Article ID 861869):1-10.
  4. Guckenberger M, Roesch J, Baier K, Sweeney RA and Flentje M. 2012. Dosimetric consequences of translation and rotational errors in frame-less image-guided radiosurgery. Radiat. Oncol. 7(1):1-8. https://doi.org/10.1186/1748-717X-7-1
  5. Holtzer N, Hoffmans D, Dahele M, Cuijpers JP, Slotman BJ and Verbakel WF. 2012. Roll and Pitch Correction in Headand-Neck Patients by Rapid Adaptation of Volumetric Modulated Arc Treatment Plans. Int. J. Radiat. Oncol. Biol. Phys. 84(3): S28-S29.
  6. Hussein M and Rowshanfarzad P. 2013. A comparison of the gamma index analysis in various commercial IMRT/VMAT QA systems. Radiother. Oncol. 109(3):370-376. https://doi.org/10.1016/j.radonc.2013.08.048
  7. Kim DH, Kim YT, Ki YG, Nam JH and Lee MR. 2011. Location error od the in a two-dimensional set-up verification during head and neck radiotherapy. J. Korean. Soc. Ther. Radiol. Oncol. 29(2):107-114. https://doi.org/10.3857/jkstro.2011.29.2.107
  8. Kim JD, Lee HO, You JM, Ji DH and Song JY. 2007. Analyses of the Setup Errors using on Board Imager (OBI). J. Korean Soc. Radiat Ther. 19(1):1-5.
  9. Kim SH, Bae SM, Seo DR, Kang TY and Bae KM. 2016. Evaluate the Implementation of Volumetric Modulated Arc Therapy QA in the Radiation Therapy Treatment according to Various Factors by Using the Portal Dosimetry. J. Korean Soc. Radia Ther. 27(2):167-174.
  10. Lee DH, Bae SM, Gwak JW, Kang TY and Baek KM. 2013. The Accuracy Evaluation according to Dose Delivery Interruption and Restart for Volumetric Modulated Arc Therapy. J. Korean Soc. Radiat Ther. 25(1):77-85.
  11. Li G, Zhang Y, Jiang X, Bai S, Peng G, Wu K and Jiang Q. 2013. Evaluation of the ArcCHECK QA system for IMRT and VMAT verification. Phys. Medica. 29(3):295-303. https://doi.org/10.1016/j.ejmp.2012.04.005
  12. Stasi M, Bresciani S, Miranti A, Maggio A, Sapino V and Gabriele P. 2012. Pretreatment patient-specific IMRT quality assurance : a correlation study between gamma index and patient clinical dose volume histogram. Med. Phys. 39(12):7626-7634. https://doi.org/10.1118/1.4767763
  13. Stock M, Kroupa B and Georg D. 2005. Interpretation and evaluation of the ${\gamma}$ index and the ${\gamma}$ index angle for the verification of IMRT hybrid plans. Phys. Med. Biol. 50(3):399-411. https://doi.org/10.1088/0031-9155/50/3/001