쇄골상부림프절을 포함한 유방암 방사선 치료 시 접합부 선량에 관한 고찰

A study on Dose of the Junction in Radiotherapy of Breast Cancer including SCL.

  • 정우현 (분당 서울대학교 병원 방사선 종양학과) ;
  • 홍주완 (분당 서울대학교 병원 방사선 종양학과) ;
  • 원희수 (분당 서울대학교 병원 방사선 종양학과) ;
  • 장남준 (분당 서울대학교 병원 방사선 종양학과) ;
  • 최병돈 (분당 서울대학교 병원 방사선 종양학과)
  • Jung, Woo Hyun (Department of Radiation Oncology, Seoul National University Bundang Hospital) ;
  • Hong, Joo Wan (Department of Radiation Oncology, Seoul National University Bundang Hospital) ;
  • Won, Hui Su (Department of Radiation Oncology, Seoul National University Bundang Hospital) ;
  • Chang, Nam Jun (Department of Radiation Oncology, Seoul National University Bundang Hospital) ;
  • Choi, Byeong Don (Department of Radiation Oncology, Seoul National University Bundang Hospital)
  • 발행 : 2017.12.29

초록

목 적: 쇄골상부림프절(Supraclavicular Lymph Nodes, SCL)을 포함한 유방암 방사선 치료 시 조사야에 인접한 다엽 콜리메이터(Multileaf Collimator, MLC)가 접합부 선량에 미치는 영향을 평가하고자 한다. 대상 및 방법: 접선 조사 기법을 이용하여 SCL을 포함한 유방암 방사선 치료 환자 30명을 대상으로 120-leaf Millennium MLC가 장착된 21EX-S의 6 MV 광자선 에너지를 사용하였다. 치료계획은 유방조직과 SCL 조사야 접합부에 MLC가 모두 위치한 Plan1, 유방조직과 SCL 조사야에 MLC가 각각 위치한 Plan2, Plan3, 그리고 MLC를 모두 Retract 한 Plan4로 하였으며, SCL 조사야는 모든 계획에서 콜리메이터 각도를 $0^{\circ}$, $270^{\circ}$로 나누어 수립하였다. 치료계획에 대한 평가는 접합부 3 cm 깊이 선량(D3 cm)의 평균값으로 비교하였고, Map-CHECK을 이용하여 각 치료계획별 접합부 선량을 측정하였다. 결 과: 치료계획 비교 결과, D3cm의 평균값은 SCL 콜리메이터 $0^{\circ}$에서 4131.1, 4215.9, 4351.4, 4423.0 cGy였고, $270^{\circ}$에서 4044.3, 4246.7, 4291.1, 4441.2 cGy로 나타났다. 콜리메이터 각도에 따른 평균 선량 변화는 SCL 조사야에 MCL가 위치한 Plan1, Plan3 이 MLC가 Retract된 나머지에 비해 크게 나타났다. 그리고 접합부 선량 측정값 또한 치료계획과 같은 경향을 보였다. 결 론: 본 연구를 통해 SCL을 포함한 유방암 방사선 치료계획 시, MLC를 접합부로부터 5 mm Retract 시켜줌으로써 MLC가 접합부 선량에 미치는 영향을 줄일 수 있을 것으로 사료된다.

Purpose: A purpose of this study was to compare dose of junction between breast and SCL fields in radiation therapy by MLC located at the junction. Materials and Methods: With 6 MV of 21EX-S equipped with 120-leaf Millennium MLC, treatment plans were designed with 30 patients who underwent radiation therapy using TFT. Plan 1 where the MLC was all used at the junction. In plan 2 and plan 3, MCLs were retracted 5 mm from breast and SCL, respectively. Plan 4 with all of MLC retracted at the junction were designed. In all of the plans, collimator angle for SCL field was divided into $0^{\circ}$ and $270^{\circ}$. To verify junction dose, the dose at 3cm depth of junction was compared with average value by MapCHECK. Results: In case of the SCL field with $0^{\circ}$ collimator angle, average value of D3cm was 4131.1, 4215.9, 4351.4, and 4423.0 cGy. In case of the SCL field with $270^{\circ}$ collimator angle, average value of D3cm was 4044.3, 4246.7, 4291.1, and 4441.2 cGy. In plan1 and 3, change in average dose depending on collimator angle was changed more significantly than paln2 and 4. Dose measured at 3cm depth of junction was similar to treatment plan. Conclusion: In radiation therapy plan for breast cancer with SCL, retracting MLCs from junction between breast and SCL fields will lead to decrease effect of dose of the junction.

키워드

참고문헌

  1. Dean, J., Hansen, C. J., Westhuyzen, J., Waller, B., Turnbull, K., Wood, M., &Last, A. (2016). Tangential intensity modulated radiation therapy (IMRT) to the intact breast. Journal of medical radiation sciences, 63(4), 217-223. https://doi.org/10.1002/jmrs.185
  2. Hung, H. M. (2017). EP-1827: Dosimetric comparison of 3D-CRT, IMRT and VMAT for bilateral breast irradiation. Radiotherapy and Oncology, 123, S1000-S1001.
  3. Mazon, J. S., Santiago, M. M., Hernandez, F. S., Rodriguez, C. A., Ochoa, A. P., &Vega, J. L. (2017). IMRT vs. VMAT for breast cancer treatment using a Monte Carlo algorithm. European Journal of Cancer, 72, S27.
  4. Rosenow, U. F., Valentine, E. S., &Davis, L. W. (1990). A technique for treating local breast cancer using a single set-up point and asymmetric collimation. International Journal of Radiation Oncology* Biology* Physics, 19(1), 183-188.
  5. Lee, J. W., Hong, S., Choi, K. S., Kim, Y. L., Park, B. M., Chung, J. B., ... &Suh, T. S. (2008). Performance evaluation of field-in-field technique for tangential breast irradiation. Japanese journal of clinical oncology, 38(2), 158-163. https://doi.org/10.1093/jjco/hym167
  6. Frank, S. J., McNeese, M. D., Strom, E. A., et al. (2004). Advances in radiation treatments of breast cancer. Clinical breast cancer, 4(6), 401-406. https://doi.org/10.3816/CBC.2004.n.002
  7. Galvin, J. M. (1999, July). The multileaf collimator: a complete guide. In Proc. AAPM annual meeting.
  8. Galvin, James M., Alfred R. Smith, and Brian Lally. "Characterization of a multileaf collimator system." International Journal of Radiation Oncology* Biology* Physics 25.2 (1993): 181-192. https://doi.org/10.1016/0360-3016(93)90339-W
  9. Huq, M. S., Yu, Y., Chen, Z. P., &Suntharalingam, N. (1995). Dosimetric characteristics of a commercial multileaf collimator. Medical physics, 22(2), 241-247. https://doi.org/10.1118/1.597461
  10. Madu, C. N., Quint, D. J., Normolle, D. P., et al. (2001). Definition of the supraclavicular and infraclavicular nodes: implications for three-dimensional CT-based conformal radiation therapy. Radiology, 221(2), 333-339. https://doi.org/10.1148/radiol.2212010247
  11. Wang, C. W., Kuo, W. H., Chang, K. J., Huang, C. S., &Cheng, J. C. H. (2007). Should adjuvant radiotherapy to the supraclavicular fossa be routinely given in patients with breast conservative treatment?. Journal of surgical oncology, 96(2), 144-150. https://doi.org/10.1002/jso.20791
  12. LoSasso, T., Chui, C. S., &Ling, C. C. (1998). Physical and dosimetric aspects of a multileaf collimation system used in the dynamic mode for implementing intensity modulated radiotherapy. Medical physics, 25(10), 1919-1927.7. https://doi.org/10.1118/1.598381
  13. Galvin, J. M., Smith, A. R., & Lally, B. (1993). Characterization of a multileaf collimator system. International Journal of Radiation Oncology* Biology* Physics, 25(2), 181-192. https://doi.org/10.1016/0360-3016(93)90339-W
  14. Sykes, J. R., & Williams, P. C. (1998). An experimental investigation of the tongue and groove effect for the Philips multileaf collimator. Physics in medicine and biology, 43(10), 3157. https://doi.org/10.1088/0031-9155/43/10/034