Earticle

초록

영어

The scatter photons and photoneutrons from high energy photon beams (more than 10 MV) will increase the undesired dose to the patient and the staff working in linear accelerator room. This undesired dose which is found at out-of-field area can increase the probability of secondary malignancy. The purpose of this study is to determine the equivalent dose of scatter photons and neutrons generated by 3 different treatment techniques: 3D-conformal, intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). The measurement was performed using two types of the optically stimulation luminescence detectors (OSL and OSLN) in the Alderson Rando phantom that was irradiated by 3 different treatment techniques following the actual prostate cancer treatment plans. The scatter photon and neutron equivalent dose were compared among the 3 treatments techniques at the surface in the out-of-field area and the critical organs. Maximum equivalent dose of scatter photons and neutrons was found when using the IMRT technique. The scatter neutrons showed average equivalent doses of 0.26, 0.63 and 0.31 mSv․Gy-1 at abdominal surface region which was 20 cm from isocenter for 3D, IMRT and VMAT, respectively. The scattered photons equivalent doses were 6.94, 10.17 and 6.56 mSv․Gy-1 for 3D, IMRT and VMAT, respectively. For the 5 organ dose measurements, the scattered neutron and photon equivalent doses in out of field from the IMRT plan were highest. The result revealed that the scatter equivalent doses for neutron and photon were higher for IMRT. So the suitable treatment techniques should be selected to benefit the patient and the treatment room staff.

목차

Abstract
 1. INTRODUCTION
 2. METHODS
  2.1 Treatment planning
  2.2 Dose Measurement
  2.3 Secondary cancer risk estimation
 3. RESULTS AND DISCUSSION
  3.1 Equivalent surface doses within the in-filed and out-of-field regions.
  3.2 Equivalent doses in the organs.
  3.3 Secondary cancer risk estimation
 4. CONCLUSIONS
 ACKNOWLEDGEMENTS
 REFERENCES

키워드

저자

• Isra Israngkul Na Ayuthaya [ Department of Nuclear Engineering, Faculty of Engineering, Chulalongkorn University and Division of Radiology, Faculty of Radiation Oncology, King Chulalongkorn Memorial Hospital, Bangkok, Thailand ] Corresponding author
• Sivalee Suriyapee [ Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand ]
• Phongpheath Pengvanich [ Department of Nuclear Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  방사선방어학회지 [Journal of Radiation Protection and Research]

• 간기

  계간

• pISSN

  2508-1888

• 수록기간

  1976~2026

• 등재여부

  KCI 등재,SCOPUS

• 십진분류

  KDC 559 DDC 629