Progress in Medical Physics (한국의학물리학회지:의학물리)

Korean Society of Medical Physics (한국의학물리학회)
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Evaluation of the Feasibility of Applying Metabolic Target Volume in 4D RT Using PET/CT Image

4D RT에서 PET/CT Image를 이용한 Metabolic Target Volume 적용의 유용성 평가

  • Kim, Chang-Uk (Department of Biomedical Engineering, The Catholic University of Korea College of Medicine) ;
  • Chun, Keum-Sung (Department of Radiation Oncology, Seoul St Mary's Hospital) ;
  • Huh, Kyung-Hoon (Department of Radiation Oncology, Seoul St Mary's Hospital) ;
  • Kim, Yeon-Shil (Department of Radiation Oncology, Seoul St Mary's Hospital) ;
  • Jang, Hong-Seok (Department of Radiation Oncology, Seoul St Mary's Hospital) ;
  • Jung, Won-Gyun (Department of Biomedical Engineering, The Catholic University of Korea College of Medicine) ;
  • Xing, Lei (Department of Radiation Oncology, Stanford University) ;
  • Suh, Tae-Suk (Department of Biomedical Engineering, The Catholic University of Korea College of Medicine)
  • 김창욱 (가톨릭대학교 의과대학 의공학교실) ;
  • 천금성 (서울성모병원 방사선종양학과) ;
  • 허경훈 (서울성모병원 방사선종양학과) ;
  • 김연실 (서울성모병원 방사선종양학과) ;
  • 장홍석 (서울성모병원 방사선종양학과) ;
  • 정원균 (가톨릭대학교 의과대학 의공학교실) ;
  • ;
  • 서태석 (가톨릭대학교 의과대학 의공학교실)
  • Received : 2010.03.15
  • Accepted : 2010.04.26
  • Published : 2010.06.30
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Abstract

In this study, we evaluated feasibility of applying MTV (Metabolic Target Volume) to respiratory gated radiotherapy for more accurate treatment using various SUV (Standard Uptake Value) from PET images. We compared VOI (Volume of Interest) images from 50%, 30% and 5% SUV (standard uptake volume) from PET scan of an artificial target with GTV (Gross Tumor Volume) images defined by percentage of respiratory phase from 4D-CT scan for respiratory gated radiotherapy. It is found that the difference of VOI of 30% SUV is reduced noticeably comparing with that of 50% SUV in longitudinal direction with respect to total GTV of 4D-CT image. Difference of VOI of 30% SUV from 4D-PET image defined by respiratory phase from 25% inhalation to 25% exhalation, and GTV from 4D-CT with the same phase is shown below 0.6 cm in maximum. Thus, it is better to use 4D-PET images than conventional PET images for applying MTV to gated RT. From the result that VOI of 5% SUV from 4D-PET agrees well with reference image of 4D-CT in all direction, and the recommendation from department of nuclear medicine that 30% SUV be advised for defining tumor range, it is found that using less than 30%SUV will be more accurate and practical to apply MTV for respiratory gated radiotherapy.

본 연구는 호흡 정보를 갖고 있는 PET 영상의 표준섭취계수(SUV: standard uptake value)를 이용하여 보다 정확하고 편리한 호흡동조 방사선치료의 metabolic target volume (MTV) 적용에 대한 유용성을 평가하고자 하였다. 평가를 위해 4D 팬텀에 임의의 인공산물을 만들어 PET 영상을 획득하였으며, 최대 SUV를 기준으로 임의로 설정한 50%, 30%, 그리고 5%의 SUV에서의 VOIs (Volumes Of Interest)와 호흡동조 방사선치료를 위한 4D-CT를 통해 획득한 호흡위상백분율에서 설정한 GTV (Gross Target Volume)을 비교하였다. 4D-CT를 통해 얻은 총합 GTV와 PET 영상의 30% SUV로 얻은 VOI와의 비교는 50%의 SUV로 얻은 VOI의 비교 결과보다 종(Longitudinal) 방향에서의 오차가 상당히 감소되었으며 4D 총합 CTV와 가장 일치하는 PET 영상은 5% SUV로 얻은 VOI로 관찰되었다. 4D PET/CT에서 전체 호흡의 25% 흡기에서 25% 호기까지 호흡위상백분율 영상의 30% SUV로 얻은 VOI는 IGRT (Image-guided radiation therapy)에 적용되는 4D-CT의 동일한 호흡위상백분율 영상에서 설정한 GTV와 비교한 결과, 최대 0.5 cm 이하로 잘 일치하였으며 4D PET의 5% SUV로 얻은 VOI의 경우 모든 방향에서 잘 일치하였다. 따라서 IGRT의 MTV 적용에 있어서 일반 PET 영상의 이용보다 4D PET 영상의 적용이 더 유용함을 보였다. 본 연구결과 현재 핵의학과에서 인체종양의 VOI를 30% SUV로 권고하고 있지만 30% 이하의 주변 SUV와 구분되는 최소 SUV를 선택해 적용한다면, 더욱 유용한 MTV 적용이 될 것으로 판단된다.

Keywords

References

  1. Kara Bucci M, Alison Bevan, Mack R: Advances inRadiation Therapy : Conventional to 3D, to IMRT, to 4D, andBeyond. CA Cancer J Clin 55:117-134 (2005) https://doi.org/10.3322/canjclin.55.2.117
  2. Dawson LA, Brock KK, Kazanjian Sahira: The reproducibilityof organ position using active breathing control (ABC) duringliver radiotherapy. Int J Radiat Oncol Biol Phys 51:1410-1421(2001) https://doi.org/10.1016/S0360-3016(01)02653-0
  3. Hideo DK, Bruce CH: Respiration gated radiotherapy treatment:a technical study. Phys Med Biol 41:83-91 (1996) https://doi.org/10.1088/0031-9155/41/1/007
  4. Mageras GS, Yorke E, Rosenzweig K, et al: Fluoroscopicevaluation of diaphragmatic motion reduction with a respiratorygated radiotherapy system. J Appl Clin Med Phys 2:191-200(2001) https://doi.org/10.1120/1.1409235
  5. Ford EC, Mageras GS, Yorke E, et al: Evaluation of respiratorymovement during gated radiotherapy using film and electronicportal imaging. Int J Radiat Oncol Biol Phys 52:522-531(2002) https://doi.org/10.1016/S0360-3016(01)02681-5
  6. Wagman R, Yorke E, Ford EC, et al: Reproducibility of organposition with respiratory gating for liver tumors: use indose-escalation. Int J Radiat Oncol Biol Phys 55:659-668 (2003) https://doi.org/10.1016/S0360-3016(02)03941-X
  7. Song SY, Park SH, Yoon SM, et al: Assessment of respiratorytumor movement using 4D computed tmography for stereotacticradiosurgery in lung tumor. J Lung Cancer 6:24-28(2007) https://doi.org/10.6058/jlc.2007.6.1.24
  8. Oldham M, Guo P, Adamovics J, et al: Towards four dimensional(4D) dosimetry for radiation-therapy. J Phys Conf Ser 56:225-227 (2006) https://doi.org/10.1088/1742-6596/56/1/034
  9. Cho BC, Park SH, Park HC, et al: Analysos of respiratorymotion artifacts in PET imaging using respiratory gated PET combined with 4D-CT. Nucl Med Mol Imaging 39 (2005)
  10. Nehmeh SA, Erdi YE, Pan T, et al: Four-dimensional (4D) PET/CT imaging of the thorax. Med Phys 31:3179-3186 (2004) https://doi.org/10.1118/1.1809778
  11. Townsend DW, Beyer T, Blodgett T: PET/CT scanners: ahardware approach to image fusion. Seminars in Nuclear Medicine 33:193-204 (2003) https://doi.org/10.1053/snuc.2003.127314
  12. Antonia Dimitrakopoulou Strauss, Ludwig strauss:Quantitative studies using positron emission tomography for thediagnosis and therapy planning of oncological patients. Hell J Nucl Med 9:10-21 (2006)
  13. Choi CW: Quantitative Analysis of PET Measurements inTumors. Nucl Med Mol Imaging 60-66 (2001)
  14. Seo YS, Kwon SY, Jeong SY, et al: Correlation of pretreatment FDG uptake to therapeutic response and relapse in patients with small cell lung cancer. Nucl Med Mol Imaging 41:538-545 (2007)
  15. Olivier G. Roussel, Yilong Ma, et al: Evans. Correction forpartial volume effects in PET: principle and validation. J Nucl Med 39:904-911 (1998)
  16. Hwang HS, Bae HS: The role of positron emission tomography(PET) in radiation treatment planning. Hanyang Medical Reviews 27:76-85 (2007)