Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
권호 표지
DOI QR코드

DOI QR Code

Neutron dosimetry depending on the number of portals for prostate cancer IMRT(Intensity-Modulated Radiation Therapy)

전립선암의 세기조절 방사선치료 시 조사문수별 중성자선량 평가

  • Lee, Joo-Ah (Department of Radiation Oncology, Catholic University, Incheon St.Mary's Hospital) ;
  • Son, Soon-Yong (Department of Radiology, Asan Medical Center) ;
  • Min, Jung-Whan (Department of Radiology, Shin-Gu University) ;
  • Choi, Kwan-Woo (Department of Radiology, Asan Medical Center) ;
  • Na, Sa-Ra (Department of Radiology, Asan Medical Center) ;
  • Jeong, Hoi-Woun (Department of Radiology, Baekseok Culture University)
  • 이주아 (가톨릭대학교 인천성모병원 방사선종양학과) ;
  • 손순룡 (서울아산병원 영상의학과) ;
  • 민정환 (신구대학교 방사선과) ;
  • 최관우 (서울아산병원 영상의학과) ;
  • 나사라 (서울아산병원 영상의학과) ;
  • 정회원 (백석문화대학교 방사선과)
  • Received : 2014.02.14
  • Accepted : 2014.06.12
  • Published : 2014.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

The aim of this study was provide basic information and establish the criteria in radiation therapy planning by measuring the absorbed neutron dose of normal tissues and lesions according to the number of portals. From September 2013 to January 2014, 20 patients who were diagnosed with prostate cancer and were previously treated with radiation therapy were replanned retrospectively to measure the absorbed neutron dose distribution according to the number of portals. The absorbed neutron dose was measured in each of the 5, 7 and 9 portals using a 15 MV energy, which meant a therapeutic dose of 220 cGy. The optical stimulation luminescence dosimeter was separated by 20cm and 60cm away from the center of the field of view. As a result, the average radiation dose in the abdomen appeared to have a positive relationship with the number of portals, which was statistically significant (p<.05). The average radiation dose was $4.34{\pm}1.08$. The average radiation dose in the thyroid was $2.71{\pm}.37$. Although it showed a positive relationship with the number of portals, it did not have statistical significance. The number of portals and the neutron dose depending on the position showed a significant positive relationship, particularly in the abdomen. As a result of linear regression analysis, as the number of the portal increased in steps, the average volume of the neutrons increased significantly (0.416 times). In conclusion, efficient selection of the number of portals is needed considering the difference in the absorbed neutron dose in the normal tissues depending on the number of the portals.

본 연구는 방사선치료를 시행한 환자를 대상으로 치료계획을 재수립한 다음, 세기조절 방사선치료를 이용하여 조사문수별 주변조직과 위치별 중성자 선량을 측정하여 차이를 비교하여 치료계획 수립에 있어 기초 자료를 제공하고자 하였다. 2013년 9월부터 2014년 1월까지 전립선암을 진단받아 방사선치료를 받은 20명의 환자를 대상으로 하였으며, 조사문수 변화에 따른 중성자의 선량 분포를 측정하기 위하여 각 연구대상자별 치료계획을 재수립하였다. 연구방법은 조사문수를 5문, 7문, 9문으로 구분하여 조사야 중심에서 20cm와 60cm 거리에 광자극 발광선량계를 위치시킨 다음, 15 MV 에너지로 220 cGy의 치료선량을 조사하여 중성자선량을 비교하였다. 연구 결과, 복부 위치에서 선량은 평균 $4.34{\pm}1.08$로 나타났고, 조사문수가 증가할수록 높은 경향을 보였으며, 통계적으로 유의한 차이를 보였다(p<.05). 갑상선위치의 평균 선량은 $2.71{\pm}.37$로 나타났으며, 조사문수에 따라 증가하는 경향을 보였으나, 통계적인 유의성은 없었다. 조사문수와 위치별 중성자선량 발생은 복부위치에서 매우 유의한 양의 상관관계를 보였다. 선형회귀분석 결과, 조사문수가 1단계 증가할 때마다 평균적으로 중성자량이 .416배로 유의하게 증가하였다. 결론적으로 조사문수별 주변 조직에 중성자선량의 차이가 발생하므로 치료계획 설계에 있어서 효율적인 조사문수의 선택이 필요하리라 사료된다.

Keywords

References

  1. Furlow, Bryant, "Prostate cancer and radiation therapy", Radiation Therapist, 21, 1, pp.29-56, 2012.
  2. Ing H, Nelson WR, Shore RA, "Unwanted photon and neutron radiation resulting from collimated photon beams interacting with the body of radiotherapy patients", Medical Physics, 9, 1, pp.27-33, 1982. DOI: http://dx.doi.org/10.1118/1.595137
  3. Alberts WG, Hollnagel RA, "Radiation weighting factor and quality factor for neutrons", Radiation Protection Dosimetry, 46, 4, 291-293, 1993.
  4. Bakiu E, Telhaj E, Kozma E, Ruci F, Malkaj P, "Comparison of 3D CRT and IMRT Treatment Plans", Acta Inform Med., 21, 3, pp.211-2. 2013. DOI: http://dx.doi.org/10.5455/aim.2013.21.211-212
  5. HS Kim, "Anticancer drug use and out- of-pocket money burden in Korean cancer patients: A questionnaire study", Korean journal of clinical pharmacy, 22, 3, pp.239-250, 2012.
  6. Rebecca M. Howell, Michele S. Ferenci, Nolan E. Hertel, and Gary D. Fullerton "Investigation of secondary neutron dose for 18 MV dynamic MLC IMRT delivery" Medical Physics, 32, 786, 2005. DOI: http://dx.doi.org/10.1118/1.1861162
  7. ON Yang, "Study on the Photoneutrons Produced in 15 MV Medical Linear Accelerators, 35, 4, 2012.
  8. Gudowska I, Brahme A, Andreo P, Gudowski W, Kierkegaard J, "Calculation of absorbed dose and biological effectiveness from photonuclear reactions in a bremsstrahlung beam of end point 50 MeV", Phys Med Biol., 44, 9, pp.2099-125, 1999. DOI: http://dx.doi.org/10.1088/0031-9155/44/9/301
  9. AAPM, "American Association of Physicist in Medicine: Neutron measurements around high energy X-ray radiotherapy machine", AAPM 19, 1986.
  10. JO Lee, "24 MV medical linear accelerator generated neutrons Study", Korean Society of Medical Physics, 16, 2, 2005.
  11. Levinger JS, Bethe HA, "Neutron yield from the nuclear photo effect", Phys Rev, 5, pp.221-222, 1952.
  12. D'Errico F, Nath R, Silvano G, Tana L, "In vivo neutron dosimetry during high-energy Bremsstrahlung radiotherapy, Int J Radiat Oncol Biol Phys., 41, 5, pp.1185-92, 1998. DOI: http://dx.doi.org/10.1016/S0360-3016(98)00162-X
  13. Hall EJ, Wuu C, "Radiation-induced second cancers the impact of 3D-CRT and IMRT", Int J Radiation Oncology Biol Phys., 56, pp.83-88, 2003. https://doi.org/10.1016/S0360-3016(03)00073-7
  14. Zanini A, Durisi E, Fasolo F: "Monte Carlo simulation of photoneutron field in linac radiotherapy treatments with different collimation system". Phys Med Biol., 49, 2, pp.571-2582, 2004. https://doi.org/10.1088/0031-9155/49/4/008
  15. Rivera JC, Falcao RC, deAlmeida CE, "The measurement of photoneutron dose in the vicinity of clinical linear accelerators, Radiation Protection Dosimetry, 130, 403-409, 2008. https://doi.org/10.1093/rpd/ncn065
  16. Passmore C, Kirr M, "Neutron response characterisation of an OSL neutron dosemeter", Radiat Prot Dosimetry, 144, 1-4, pp.155-60, 2011.
  17. SY Son, A Study on Analyzing Factors Influencing on the Integrated Bolus Peak Timing in Contrast-enhanced Brain Magnetic Resonance Angiography and Bolus Tracking Computed Tomographic Angiography, Hanyang university, 2013.
  18. FW Spiers, "Inverse Square Law Errors in Gamma-ray Dose Measurements", http://dx. doi.org/10.1259/0007-1285-14-161-147. 1941.
  19. CS Park, "A Study on the Neutron Dose Distribution in Case of 10 MV X-rays Radiotherapy", Korean society of radiological science, 31, 4, pp.415-427, 2008.

Cited by

  1. Evaluation of Photoneutron During Radiation Therapy when Using Flattening Filter and Tracking Jaw with High Energy X-ray vol.10, pp.2, 2016, https://doi.org/10.7742/jksr.2016.10.2.125