Analysis on the Calculated Dose in the Lung Radiation Surgery Planning Using TomoTherpay

토모테라피를 이용한 폐종양 방사선수술 계획 시 선량 분석

  • Song, Ju-Young (Department of Radiation Oncology, Chonnam National University Medical School) ;
  • Jung, Jae-Uk (Department of Radiation Oncology, Chonnam National University Medical School) ;
  • Yoon, Mee-Sun (Department of Radiation Oncology, Chonnam National University Medical School) ;
  • Ahn, Sung-Ja (Department of Radiation Oncology, Chonnam National University Medical School) ;
  • Chung, Woong-Ki (Department of Radiation Oncology, Chonnam National University Medical School) ;
  • Nah, Byung-Sik (Department of Radiation Oncology, Chonnam National University Medical School) ;
  • Nam, Taek-Keun (Department of Radiation Oncology, Chonnam National University Medical School)
  • 송주영 (전남대학교 의과대학 방사선종양학교실) ;
  • 정재욱 (전남대학교 의과대학 방사선종양학교실) ;
  • 윤미선 (전남대학교 의과대학 방사선종양학교실) ;
  • 안성자 (전남대학교 의과대학 방사선종양학교실) ;
  • 정웅기 (전남대학교 의과대학 방사선종양학교실) ;
  • 나병식 (전남대학교 의과대학 방사선종양학교실) ;
  • 남택근 (전남대학교 의과대학 방사선종양학교실)
  • Received : 2011.10.20
  • Accepted : 2011.12.05
  • Published : 2011.12.30

Abstract

The applicability and feasibility of TomoTherapy in the lung radiation surgery was analyzed by comparison of the calculated dose distribution in TomoTherapy planning with the results of conventional IMRS (intensity modulated radiation surgery) using LINAC (linear accelerator). The acquired CT (computed tomograph) images of total 10 patients whose tumors' motion were less than 5 mm were used in the radiation surgery planning and the same prescribed dose and the same dose constraints were used between TomoTherapy and LINAC. The results of TomoTherapy planning fulfilled the dose requirement in GTV (gross tumor volume) and OAR (organ at risk) in the same with the conventional IMRS using LINAC. TomoTherapy was superior in the view point of low dose in the normal lung tissue and conventional LINAC was superior in the dose homogeneity in GTV. The calculated time for treatment beam delivery was long more than two times in TomoTherapy compared with the conventional LINAC. Based on the results in this study, TomoTherapy can be evaluated as an effective way of lung radiation surgery for the patients whose tumor motion is little when the optimal planning is produced considering patient's condition and suitability of dose distribution.

본 연구에서는 토모테라피를 이용한 폐종양의 방사선수술 치료계획을 수립한 후 기존의 선형가속기를 사용하였을 경우와 비교, 분석하여 선량분포 측면에서 유효성 및 타당성을 살펴보았다. 종양의 움직임이 5 mm 이하인 10명의 환자 CT 영상을 대상으로 기존의 선형가속기를 이용한 세기조절방사선수술에서와 동일한 처방선량과 동일한 조건의 중요장기 선량제한치로 토모테라피 치료계획을 수립한 후 선량분포를 비교하였다. 토모테라피를 이용한 결과에서도 기존의 선형가속기를 이용한 세기조절방사선수술과 동일하게 중요장기의 선량제한치를 충족시키면서 GTV에 처방선량을 부여할 수있음을 확인하였다. 방사선조사로 인한 폐의 정상조직합병증확률과 종양 반대편 폐의 등가균일선량 측면에서는 토모테라피가 기존 선형가속기보다 상대적으로 더 우수한 결과를 보였으나, 종양 내 치료선량 분포의 균일도에서는 기존 선형 가속기가 더 양호한 결과를 보였다. 치료 빔 전달 시간측면에서는 토모테라피가 기존 선형가속기 경우보다 2배 이상의 시간이 소요되었다. 이와 같은 본 연구의 결과 분석을 통해 폐종양 부위의 움직임이 적은 경우, 환자의 상태와 선량분포의 적합성 등을 고려한 최적의 치료계획을 세운다면 토모테라피를 사용하는 방사선 수술이 유효성 및 타당성이 있음을 확인할 수 있었다.

Keywords

References

  1. Han C, Liu A, Schultheiss, et al: Dosimetric comparison of helical tomotherapy treatment plans and step-and-shoot intensity- modulated radiosurgery treatment plans in intracranial stereotactic radiosurgery. Int J Radiat Oncol Biol Phys 65:608- 616 (2006) https://doi.org/10.1016/j.ijrobp.2006.01.045
  2. Sheehan JP, Shaffrey CI, Schlesinger D, et al: Radiosurgery in the treatment of spinal metastases: tumor control, survival, and quality of life after helical tomotherapy. Neurosurgery 65:1052-1061 (2009) https://doi.org/10.1227/01.NEU.0000359315.20268.73
  3. Vanderspek L, Bauman G, Wang JZ, et al: Dosimetric comparison of intensity-modulated radiosurgery and helical tomotherapy for the treatment of multiple intracranial metastases. Technol Cancer Res Treat 8:361-367 (2009) https://doi.org/10.1177/153303460900800506
  4. Lee TF, Chao PJ, Wang CY, et al: Dosimetric comparison of helical tomotherapy and dynamic conformal arc therapy in stereotactic radiosurgery for vestibular schwannomas. Med Dosim 36:62-70 (2011) https://doi.org/10.1016/j.meddos.2009.11.005
  5. Soisson ET, Hoban PW, Kammeyer T, et al: A technique for stereotactic radiosurgery treatment planning with helical tomotherapy. Med Dosim 36:46-56 (2011) https://doi.org/10.1016/j.meddos.2009.11.003
  6. Soisson ET, Tome WA, Richards GM, et al: Comparison of linac based fractionated stereotactic radiotherapy and tomotherapy treatment plans for skull-base tumors. Radiother Oncol 78: 313-321 (2006) https://doi.org/10.1016/j.radonc.2006.01.005
  7. Soisson ET, Mehta MP, Tome WA: A comparison of helical tomotherapy to circular collimator-based linear-accelerator radiosurgery for the treatment of brain metastasis. Am J Clin Oncol 34:388-394 (2011) https://doi.org/10.1097/COC.0b013e3181e9c0ee
  8. Kumar T, Rakowski J, Zhao B, et al: Helical TomoTherapy versus stereotactic Gamma Knife radiosurgery in the treatment of single and multiple brain tumors: a dosimetric comparison. J Appl Clin Med Phys 11:3245 (2010)
  9. Marks LB, Hanken RK, Martel MK: Quantitative analyses of normal tissue effects in the clinic. Int J Radiat Oncol Biol Phys 76:S20-S107 (2010) https://doi.org/10.1016/j.ijrobp.2009.02.091
  10. 김진성, 윤명근, 박성용 등: 방사선치료 관련 연구를 위한 선량 체적 히스토그램 분석 프로그램 개발. 대한방사선종양학회지 27:240-248 (2009)
  11. Jones LC, Hoban PW: Treatment plan comparison using equivalent uniform biologically effective dose (EUBED). Phys Med Biol 45:159-170 (2000) https://doi.org/10.1088/0031-9155/45/1/311
  12. Niemierko A: Reporting and analyzing dose distributions; a concept of equivalent uniform dose. Med Phys 24:103-110 (1997) https://doi.org/10.1118/1.598063
  13. Luxton G, Keall PJ, King CR: A new formula for normal tissue complication probability (NTCP) as a function of equivalent uniform dose (EUD). Phys Med Biol 53:23-36 (2008) https://doi.org/10.1088/0031-9155/53/1/002
  14. Kutcher GJ, Burman C, Brewster L, et al: Histogram reduction method for calculating complication probabilities for three-dimensional treatment planning evaluations. Int J Radiat Oncol Biol Phys 21:137-146 (1991)
  15. Lyman JT: Normal tissue complication probabilities: variable dose per fraction. Int J Radiat Oncol Biol Phys 22:247-250 (1992) https://doi.org/10.1016/0360-3016(92)90040-O
  16. Semeneko VA, Li XA: Lyman-kutcher-Buman NTCP model parameters for radiation pneumonitis and xerostomia based on combined analysis of published clinical data. Phys Med Biol 53:737-755 (2008) https://doi.org/10.1088/0031-9155/53/3/014
  17. Wu Q, Mohan R, Morris M, et al: Simultaneous integrated boost intensity modulated radiotherapy for locally advanced head-and neck squamous cell carcinomas. I: dosimetric results. Int J Radiat Oncol Biol Phys 56:573-585 (2003) https://doi.org/10.1016/S0360-3016(02)04617-5
  18. Zhang T, Lu W, Olivera GH, et al: Breathing-synchronized delivery: a potential four-dimensional tomotherapy treatment technique. Int J Radiat Oncol Biol Phys 68:1572-1578 (2007) https://doi.org/10.1016/j.ijrobp.2007.02.054
  19. Lu W: Real-time motion-adaptive-delivery (MAD) using binary MLC: II. Rotational beam (tomotherapy) delivery. Phys Med Biol 53:6513-6531 (2008) https://doi.org/10.1088/0031-9155/53/22/015
  20. Lu W, Chen M, Ruchala KJ, et al: Real-time motionadaptive- optimization (MAO) in TomoTherapy. Phys Med Biol 54:4374-4398 (2009)