초록

- 몬테카를로 방법을 이용하여 즉발감마선 분포측정을 위한 콜리메이터 설계.
- 즉발감마선 콜리메이션 시스템 (Prompt Gamma Scanner, PGS) 및 제어관련 시스템의 기계적 설계 및 제작.
- 원자력의학원 MC-50 사이클로트른 및 국립암센터 양성자가속기 빔 (80-230 MeV)을 이용하여 물 팬텀에서 발생하는 즉발감마선 분포를 측정하고 이온챔버를 사용하여 측정한 깊이방향의 선량분포와 비교분석.

Abstract ▼

In radiation therapy using a proton beam it is difficult to know the actual dose distribution because protons stop in the patient unlike photons of the conventional radiation therapy. The only way of finding out the dose distribution is to measure the gammas produced by the nuclear reactions with ti

In radiation therapy using a proton beam it is difficult to know the actual dose distribution because protons stop in the patient unlike photons of the conventional radiation therapy. The only way of finding out the dose distribution is to measure the gammas produced by the nuclear reactions with tissue materials. Two kinds of gammas can be used: one is prompt gamma and the other is coincident gamma from the positron-emission isotopes. We have designed a collimator system to measure the distribution of prompt gammas with a millimeter positional accuracy. The collimator was designed using the Monte Carlo programs including MCNPX. To suppress the neutrons generated together with gammas the collimator has a three-layer structure, which moderates high-energy neutrons with paraffin, captures thermalized neutrons with $B_4C$, and shields gammas generated from the capture reaction. The prompt gamma was measured at the beam energy of 40 MeV first at the Korea Cancer Center Hospital, and then at 110 MeV from the 230-MeV cyclotron of National Cancer Center. We could observe that the gamma production rate reduces considerably in the region of the distal fall-off. Further empirical studies will reveal more detailed relationship between the dose distribution measured with the ionization chamber and the distribution of the prompt gammas in the therapy energy range of 70-230 MeV.

목차 Contents

• 표지...1
• 제출문...2
• 요약문...3
• SUMMARY...4
• CONTENTS...5
• 목차...6
• 제 1 장 과제 개요...7
• 제 2 장 국내.외 기술개발 현황...8
• 제 3 장 연구개발수행 내용 및 결과...11
• 제 4 장 연구개발 목표 달성도 및 관련 분야에의 기여도...18
• 제 5 장 연구개발결과의 활용계획...19
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보...20
• 제 6 장 참고문헌...21