Journal of radiological science and technology (대한방사선기술학회지:방사선기술과학)

Korean Society of Radiological Science (대한방사선과학회)
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Comparison of 2D and 3D Brachytherapy Planning for Cervical Cancer

자궁경부암 근접방사선치료 시 2차원, 3차원 치료계획 비교평가

  • Kim, Jung Hoon (Department of Radiation Oncology, KonYang University Hospital)
  • 김정훈 (건양대학교병원 방사선종양학과)
  • Received : 2017.05.29
  • Accepted : 2017.06.20
  • Published : 2017.06.30
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Abstract

To evaluate the usefulness of 3-dimensional brachytherapy(BT) planning technique based on CT in cervical cancer. Patients with cervical cancer underwent 2-D BT treatment planning and then CT scan with HDR intracavitary applicators in place with same positions. Dose was prescribed to Point A with 5Gy per fraction on 2-D BT planning. For 3-D BT planning, and dose was prescribed to the High risk CTV for BT (HR CTV) with 5Gy. The 3-D BT planning goal was to cover at least 90% of the HR CTV with target 5Gy isodose surface while limiting the dose to $2cm^3$ of bladder to less than 7.5 Gy, and $2cm^3$ of rectum to less than 5Gy. In one patient of 10 patients, $D_{2cm3}$ of rectal dose was over 5Gy and 6patients at $D_{2cm3}$ of bladder dose on 2-D BT planning. There was a tendency to underestimate ICRU bladder dose than ICRU rectal dose. CT based 3-D BT planning for cervical cancer will enable evaluation of dose distributions for tumor and critical organs at risk. So, rectal and bladder morbidity as well as geographic miss will be reduced in case of the bulky disease or uterine malposition.

본 연구에서는 자궁경부암의 치료를 위한 전산화단층촬영(computer tomography)영상을 이용한 3차원 근접치료계획의 유용성을 알고자 하였다. 10명의 자궁경부암 환자에서 2차원 근접치료계획을 시행하였고, 동일 자세로 전산화단층촬영을 시행하였다. 3차원 근접치료계획 프로그램(ECLIPSE treatment planning system v6.5, Varian Medical System, USA)를 이용하였으며, 고위험임상표적체적(High risk CTV, HR CTV)에 5 Gy를 처방하였다. 3차원 근접치료계획의 제한은 적어도 고위험임상표적체적의 90%에 처방선량인 5 Gy가 조사되도록, 방광의 $2cm^3$에 7.5 Gy 미만으로 들어가도록 그리고 직장의 $2cm^3$에 5 Gy 미만이 들어가도록 하였다. 계획의 평가는 선량체적표(dose-volume histograms; DVHs)를 이용하여 육안적종양체적(Gross tumor volume for brachytherapy; $GTV_B$), 고위험임상표적체적, 직장과 방광에 조사되는 선량을 구하였다. 크기가 큰 종양이나 자궁의 위치이상이 있는 환자에서 Point A에 처방한 2차원 근접치료계획을 하였을 경우에는 고위험임상표적체적이 충분히 포함되지 않았다. 그러나 3차원 근접치료계획은 이러한 환자들에서 직장이나 방광의 선량을 증가시키지 않고 고위험임상표적체적을 잘 포함할 수 있었다. 2차원 근접치료계획에서 높은 선량부터 $2cm^3$에 들어가는 직장선량은 10명 중 1명에서, $2cm^3$에 들어가는 방광선량은 6명에서 5 Gy를 넘었으므로 ICRU (International Commission on Radiation Units) 방광선량이 직장선량에 비해 과소평가됨을 확인할 수 있었다. 자궁경부암 환자에서 전산화단층촬영 이용한 3차원 근접치료계획은 종양과 위험장기에 대한 선량평가가 가능하므로, 직장과 방광의 부작용을 증가시키지 않으면서 크기가 큰 종양이나 자궁의 위치이상이 있는 환자에서 위치 설정의 오류를 줄일 수 있을 것으로 생각된다.

Keywords

References

  1. A namaria RY, Robert JA, Christoper GM, et al.: Long-term outcome after radiotherapy for FIGO stage IIIB and IVA carcinoma of the cervix, 67(5), 144-1450, 2007 https://doi.org/10.1016/j.ijrobp.2006.08.051
  2. A ndrzej R, Zaneta WF, Krystyna B, et al.: Incidence of radiation toxicity in cervical cancer and endometrial cancer patients treated with radiotherapy alone versus adjuvant radiotherapy, 17, 332-338, 2012 https://doi.org/10.1016/j.rpor.2012.07.005
  3. Barillot I, Horiot JC, Maingon P, et al.: Comparison of Computed Tomography and MRI-based clinical target volume vontours at the time of brachytherapy for cervical cancer, Int J Radiat Oncol Biol Phys., 96(4), 793-800, 2016 https://doi.org/10.1016/j.ijrobp.2016.07.035
  4. T amaki T, Miyaura K, Murakami T, et al.: The use of trans-applicator intracavitary ultrasonography in brachytherapy for cervical cancer: phantom study of a novel approach to 3D image-guided brachytherapy, J Contemp Brachytherapy, 9(2), 151-157, 2017
  5. S t-Amant P, Foster W, Froment MA, et al.: Use of 3D transabdominal ultrasound imaging for treatment planning in cervical cancer brachytherapy: Comparison to magnetic resonance and computed tomography, Brachytherapy, article in press, 2017
  6. W achter-Gerstner N, Wachter S, Reinstadler E, et al.: The impact of sectional imaging on dose escalation in endocavitary HDR-brachytherapy of cervical cancer: results of a prospective comparative trial. Radiother Oncol, 68(1), 51-59, 2003 https://doi.org/10.1016/S0167-8140(03)00083-5
  7. A lfredo P: Image fusion techniques in permanent seed implantation, J Contemp Brachytherapy, 2(3), 98-106, 2010
  8. P elloski CE, Palmer M, Chronowski GM, et al.: Comparison between CT-based volumetric calculations and ICRU reference-point estimates of radiation doses delivered to bladder and rectum during intracavitary radiotherapy for cervical cancer. Int J Radiat Oncol Biol Phys, 62(1), 131-137, 2005 https://doi.org/10.1016/j.ijrobp.2004.09.059
  9. N atascha WG, Stefan W, Evi R, et al.: Bladder and Rectum dose defined from MRI based treatment planning for cervix cancer brachytherapy: comparison of does-volume histograms for organ contours and organ wall, comparison with ICRU rectum and bladder reference point, 68, 269-276, 2003 https://doi.org/10.1016/S0167-8140(03)00189-0
  10. H aie-Meder C, Potter R, Van Limbergen E, et al.: Recommendations from Gynaecological (GYN) GEC-ESTRO Working Group (I): concepts and terms in 3D image based 3D treatment planning in cervix cancer brachytherapy with emphasis on MRI assessment of GTV and CTV. Radiother Oncol, 74(3), 235-245, 2005 https://doi.org/10.1016/j.radonc.2004.12.015
  11. P otter R, Haie-Meder C, Van Limbergen E, et al.: Recommendations from gynaecological (GYN) GEC ESTRO working group (II): concepts and terms in 3D image-based treatment planning in cervix cancer brachytherapy-3D dose volume parameters and aspects of 3D image-based anatomy, radiation physics, radiobiology. Radiother Oncol, 78(1), 67-77, 2006 https://doi.org/10.1016/j.radonc.2005.11.014
  12. Lin LL, Mutic S, Low DA, LaForest R, Vicic M, Zoberi I, et al.: Adaptive brachytherapy treatment planning for cervical cancer using FDG-PET. Int J Radiat Oncol Biol Phys, 67(1), 91-96, 2007 https://doi.org/10.1016/j.ijrobp.2006.08.017
  13. Wachter-Gerstner N, Wachter S, Reinstadler E, et al.: Bladder and rectum dose defined from MRI based treatment planning for cervix cancer brachytherapy: comparison of dose-volume histograms for organ contours and organ wall, comparison with ICRU rectum and bladder reference point. Radiother Oncol, 68(3), 269-276, 2003 https://doi.org/10.1016/S0167-8140(03)00189-0
  14. Pelloski CE, Palmer M, Chronowski GM, et al.: Comparison between CT-based volumetric calculations and ICRU reference-point estimates of radiation doses delivered to bladder and rectum durin IIIg intracavitary radiotherapy for cervical cancer. Int J Radiat Oncol Biol Phys, 62(1), 131-137, 2005 https://doi.org/10.1016/j.ijrobp.2004.09.059