The Journal of Korean Society for Radiation Therapy (대한방사선치료학회지)

Korean Society for Radiation Therapy (대한방사선치료학회)
권호 표지

Evaluation of HalcyonTM Fast kV CBCT effectiveness in radiation therapy in cervical cancer patients of childbearing age who performed ovarian transposition

난소전위술을 시행한 가임기 여성의 자궁경부암 방사선치료 시 난소선량 감소를 위한 HalcyonTM Fast kV CBCT의 유용성 평가 : Phantom study

  • Lee Sung Jae (Department of Radiation Oncology, Asan Medical Center) ;
  • Shin Chung Hun (Department of Radiation Oncology, Asan Medical Center) ;
  • Choi So Young (Department of Radiation Oncology, Asan Medical Center) ;
  • Lee Dong Hyeong (Department of Radiation Oncology, Asan Medical Center) ;
  • Yoo Soon Mi (Department of Radiation Oncology, Asan Medical Center) ;
  • Song Heung Gwon (Department of Radiation Oncology, Asan Medical Center) ;
  • Yoon In Ha (Department of Radiation Oncology, Asan Medical Center)
  • 이성재 (서울아산병원 방사선종양학과) ;
  • 신충훈 (서울아산병원 방사선종양학과) ;
  • 최소영 (서울아산병원 방사선종양학과) ;
  • 이동형 (서울아산병원 방사선종양학과) ;
  • 유순미 (서울아산병원 방사선종양학과) ;
  • 송흥권 (서울아산병원 방사선종양학과) ;
  • 윤인하 (서울아산병원 방사선종양학과)
  • Published : 2022.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

Purpose: The purpose of this study is to evaluate the effectiveness of reducing the absorbed dose to the ovaries and the quality of the CBCT image when using the HalcyonTM Fast kV CBCT of cervical cancer patients of child-bearing age who performed ovarian transposition Materials and Methods : Contouring of the cervix and ovaries required for measurement was performed on the computed tomography images of the human phantom (Alderson Rando Phantom, USA), and three Optically Stimulated Luminescence Dosimeter(OSLD) were attached to the selected organ cross-section, respectively. In order to measure the absorbed dose to the cervix and ovaries in the TruebeamTM pelvis mode (Hereinafter referred to as TP), The HalcyonTM Pelvis mode (Hereinafter referred to as HP) and The HalcyonTM Pelvis Fast mode (Hereinafter referred to as HPF), An image was taken with a scan range of 17.5 cm and also taken an image that reduced the Scan range to 12.5cm. A total of 10 cumulative doses were summed, It was replaced with a value of 23 Fx, the number of cervical cancer treatments, and compared In additon, uniformity, low contrast visibility, spatial resolution, and geometric distortion were compared and analyzed using Catphan 504 phantom to compare CBCT image quality between equipment. Each factor was repeatedly measured three times, and the average value was obtained by analysing with the Doselab (Mobius Medical Systems, LP. Versions: 6.8) program. Results: As a result of measuring absorbed dose by CBCT with OSLD, TP and HP did not obtain significant results under the same conditions. The mode showing the greatest reduction value was HPF versus TP. In HPF, the absorbed dose was reduced by 39.8% in the cervix and 19.8% in the ovary compared to the TP in the scan range of 17.5 cm. the scan range was reduced to 12.5 cm, absorbed dose was reduced by 34.2% in the cervix and 50.5% in the ovary. In addition, result of evaluating the quality of the image used in the above experiment, it complied with the equipment manufacturer's standards with Geometric Distortion within 1mm (SBRT standard), Uniformity HU, LCV within 2.0%, Spatial Resolution more than 3 lp/mm. Conclusion: According to the results of this experiment, HalcyonTM can select more various conditions than TruebeamTM in treatment of fertility woman who have undergone ovarian Transposition , because it is important to reduce the radiation dose by CBCT during radiation therapy. So finally we recommend HalcyonTM Fast kV CBCT which maintains image quality even at low mAs. However, it is consider that the additional exposure to low doses can be reduced by controlling the imaging range for patients who have undergone ovarian transposition in other treatment machines.

목 적: 본 연구는 난소전위술을 시행한 가임기 여성의 자궁경부암 방사선치료 시 HalcyonTM Fast kV CBCT를 사용하였을 때 난소에 미치는 흡수선량과 영상의 품질을 분석하여 유용성을 평가하고자 한다. 대상 및 방법: 인체모형 팬텀(Alderson Rando Phantom, USA)의 전산화단층촬영 영상에 측정에 필요한 자궁경부와 난소의 윤곽묘사(contouring)를 하였고, 해당 장기 단면에 광자극발광선량계(Optically Stimulated Luminescence Dosimeter, OSLD, InLight system, Landauer, USA)를 각각 3개씩 부착하였다. TruebeamTM의 Pelvis mode(이하 TP)와 HalcyonTM의 Pelvis mode(이하 HP) 그리고 HalcyonTM의 Pelvis Fast mode(이하 HPF)에서 자궁경부와 난소에 들어가는 흡수선량을 측정하기 위해 촬영 범위를 17.5 cm와 12.5 cm로 촬영 범위를 축소한 영상을 촬영하였다. 총 10회의 누적선량을 합산하였고, 자궁경부암 치료 횟수인 23회의 값으로 치환하여 비교하였다. 또한 영상 장비 간의 CBCT 영상 품질을 비교하기 위해 Catphan 504 팬텀(The Phantom Laboratory, USA)을 이용하여 균일도(Uniformity), 저 대조도 가시(Low contrast visibility, LCV), 공간분해능(Spatial resolution), 기하학적 왜곡(Geometric Distortion)을 비교 분석하였다. 각각 3회 반복 측정하여 Doselab (Versions: 6.8, Mobius Medical Systems) 프로그램으로 분석 후 평균값을 구하였다. 결 과: CBCT에 의한 흡수선량을 OSLD로 측정한 결과 동일한 조건일 시 TP와 HP는 유의미한 결과를 얻지 못하였다. 가장 큰 감소 값을 보인 모드는 TP 대비 HPF였다. HPF는 17.5 cm의 촬영 범위에서 흡수선량이 TP보다 자궁경부가 약 39.82%, 난소에서 약 19.8% 감소 하였고, 12.5 cm 으로 촬영 범위를 축소할 경우 자궁경부는 34.2%, 난소 50.5%로 감소 시킬 수 있었다. 또한 위 실험에서 사용된 영상의 품질을 평가한 결과 Geometric Distortion 1mm 이내(SBRT 기준), Uniformity HU, LCV 2.0% 이내 Spatial Resolution 3 lp/mm 이상으로 장비사의 기준치를 준수하였다. 결 론: 본 실혐 결과에 따라 난소전위술을 시행한 가임기 여성의 방사선치료 시 CBCT로 인한 피폭선량을 낮추기 위해서는 TruebeamTM 보다 다양한 조건을 선택 할 수 있는 HalcyonTM이 유용할 것으로 평가 되며, 특히 낮은 mAs로도 영상의 품질을 유지하는 HalcyonTM의 Fast kV CBCT를 권장한다. 다만 다른 치료 장비에서도 난소전위를 시행한 환자는 촬영 범위를 조정하는 것으로 저선량에 대한 추가적인 피폭 감소시킬 수 있을 것으로 사료된다.

Keywords

References

  1. Seri Hong, Young-Joo Won, Jae Jun Lee et al. Cancer Statistics in Korea: Incidence, Mortality, Survival, and Prevalence in 2018
  2. JY Wo, AN. Viswanathan. Impact of radiotherapy on fertility, pregnancy, and neonatal outcomes in female cancer patients Int J Radiat Oncol Biol Phys, 73 (2009), pp. 1304-1312 https://doi.org/10.1016/j.ijrobp.2008.12.016
  3. Lina Yin, Saiquan Lu, et al. Ovarian transposition before radiotherapy in cervical cancer patients: functional outcome and the adequate dose constraint
  4. Michael JZ, Zvi Fuks, Margie Hunt, et al.: High-dose intensity modulated radiation therapy for prostate cancer: early toxicity and biochemical outcome in 772 patients. Int J Radiat Oncol Biol Phys, 2002;53(5):1111-6 https://doi.org/10.1016/S0360-3016(02)02857-2
  5. Choi So Young,Kim Tae Won,Kim Min Su, et al. : Phantom Study = Comparative evaluation of dose according to changes in rectal gas volume during radiation therapy for cervical cancer : Phantom Study The journal of the korean society for radio-therapeutic technology 33(-), 89-97.
  6. D. W. Kim, W. K. Chung, M. G. Yoon, "Imaging doses and secondary cancer risk from kilovoltage cone-beam CT in radiation therapy," Health physics, Vol. 104, No. 5, pp. 499-503, 2013. https://doi.org/10.1097/HP.0b013e318285c685
  7. Bin Cai 1, Eric Laugeman 1, Thomas R Mazur, et al : Characterization of a prototype rapid kilovoltage x-ray image guidance system designed for a ring shape radiation therapy unit 2019 Mar;46(3):1355-1370
  8. E.G. Yukihara, S.W. McKeever. Optically stimulated luminescence (OSL) dosimetry in medicine. Phys Med Biol, 53 (2008), pp. R351-R379
  9. Zhenia Gopalakrishnanm, Raghuram K.Nair, Saju Bhasi et al: Verification of treatment planning algorithms using optically stimulated luminescent dosimeters in a breast phantom. J med Phys. Vol 43(4) 2018:264-269 https://doi.org/10.4103/jmp.JMP_112_18
  10. Su Chul Han, Kum Bae Kim, Sang Hyoun Choi et al.: Changes of Optically Stimulated Luminescence Dosimeter Sensitivity with High Dose. Vol 27(2) 2016:98
  11. Jung Seong Ahn A study of Peripheral Area Image Quality in CBCT of Medical Linear Accelerator Department of Health Science, Graduate School, Eulji University
  12. Sameer Taneja 1, David L Barbee 1, Anthony J Rea et al.: CBCT image quality QA: Establishing a quantitative program J Appl Clin Med Phys. 2020 Nov;21(11):215-225.