DOI QR코드

DOI QR Code

The Feasibility Study of MRI-based Radiotherapy Treatment Planning Using Look Up Table

Look Up Table을 이용한 자기공명영상 기반 방사선 치료계획의 타당성 분석 연구

  • Kim, Shin-Wook (Department of Radiation Oncology, Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Shin, Hun-Joo (Department of Radiation Oncology, Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Lee, Young-Kyu (Department of Radiation Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Seo, Jae-Hyuk (Department of Radiation Oncology, Bucheon St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Lee, Gi-Woong (Department of Medical Physics, Kyonggi University of Korea, School of Medicine) ;
  • Park, Hyeong-Wook (Department of Medical Physics, Kyonggi University of Korea, School of Medicine) ;
  • Lee, Jae-Choon (Department of Medical Physics, Kyonggi University of Korea, School of Medicine) ;
  • Kim, Ae-Ran (Department of Bio Medical Engineering, The Catholic University of Korea School of Medicine) ;
  • Kim, Ji-Na (Department of Bio Medical Engineering, The Catholic University of Korea School of Medicine) ;
  • Kim, Myong-Ho (Department of Radiation Oncology, Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Kay, Chul-Seung (Department of Radiation Oncology, Incheon St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Jang, Hong-Seok (Department of Radiation Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea School of Medicine) ;
  • Kang, Young-Nam (Department of Radiation Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea School of Medicine)
  • 김신욱 (가톨릭대학교 의과대학 인천성모병원) ;
  • 신헌주 (가톨릭대학교 의과대학 인천성모병원) ;
  • 이영규 (가톨릭대학교 의과대학 서울성모병원) ;
  • 서재혁 (가톨릭대학교 의과대학 부천성모병원 방사선종양학교실) ;
  • 이기웅 (경기대학교 의학물리학과) ;
  • 박형욱 (경기대학교 의학물리학과) ;
  • 이재춘 (경기대학교 의학물리학과) ;
  • 김애란 (가톨릭대학교 의과대학 의공학교실) ;
  • 김지나 (가톨릭대학교 의과대학 의공학교실) ;
  • 김명호 (가톨릭대학교 의과대학 인천성모병원) ;
  • 계철승 (가톨릭대학교 의과대학 인천성모병원) ;
  • 장홍석 (가톨릭대학교 의과대학 서울성모병원) ;
  • 강영남 (가톨릭대학교 의과대학 서울성모병원)
  • Received : 2013.11.29
  • Accepted : 2013.12.09
  • Published : 2013.12.31

Abstract

In the intracranial regions, an accurate delineation of the target volume has been difficult with only the CT data due to poor soft tissue contrast of CT images. Therefore, the magnetic resonance images (MRI) for the delineation of the target volumes were widely used. To calculate dose distributions with MRI-based RTP, the electron density (ED) mapping concept from the diagnostic CT images and the pseudo CT concept from the MRI were introduced. In this study, the look up table (LUT) from the fifteen patients' diagnostic brain MRI images was created to verify the feasibility of MRI-based RTP. The dose distributions from the MRI-based calculations were compared to the original CT-based calculation. One MRI set has ED information from LUT (lMRI). Another set was generated with voxel values assigned with a homogeneous density of water (wMRI). A simple plan with a single anterior 6MV one portal was applied to the CT, lMRI, and wMRI. Depending on the patient's target geometry for the 3D conformal plan, 6MV photon beams and from two to five gantry portals were used. The differences of the dose distribution and DVH between the lMRI based and CT-based plan were smaller than the wMRI-based plan. The dose difference of wMRI vs. lMRI was measured as 91 cGy vs. 57 cGy at maximum dose, 74 cGt vs. 42 cGy at mean dose, and 94 cGy vs. 53 at minimum dose. The differences of maximum dose, minimum dose, and mean dose of the wMRI-based plan were lower than the lMRI-based plan, because the air cavity was not calculated in the wMRI-based plan. These results prove the feasibility of the lMRI-based planning for brain tumor radiation therapy.

References

  1. Jonsson JH, Karlsson MG, Karlsson M, Nyholm T: Treatment planning using MRI data: an analysis of the dose calculation accuracy for different treatment regions. Radiat Oncol 5:62 (2010) https://doi.org/10.1186/1748-717X-5-62
  2. Prabhakar R, Julka PK, Ganesh T, Munshi A, Joshi RC, Rath G: Feasibility of using MRI alone for 3D radiation treatment planning in brain tumors. Jpn J Clin Oncol 37(6):405-411 (2007) https://doi.org/10.1093/jjco/hym050
  3. Stanescu T, Hans-Sonke J, Stavrev P, Fallone BG: 3T MR-based treatment planning for radiotherapy of brain lesions. Radiat Oncol 40(2):125-132 (2006)
  4. Chen L, Price RA Jr, Wang L, et al: MRI-based treatment planning for radiotherapy: dosimetric verification for prostate IMRT. Int J Radiat Oncol Biol Phys 60(2):636-647 (2004) https://doi.org/10.1016/j.ijrobp.2004.07.656
  5. Wang C, Chao M, Lee L, Xing L: MRI-based treatment planning with electron density information mapped from CT. Technol Cancer Res Treat 7(5):341-347 (2008) https://doi.org/10.1177/153303460800700501
  6. Miga MI, Boettger T, Nyholm T, et al: Radiation therapy planning and simulation with magnetic resonance images. Medical Imaging 6918:19181C (2008)