• Title/Summary/Keyword: 치료방사선

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방사선은 해로운가?

  • 하성환
    • The Journal of Korean Society for Radiation Therapy
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    • v.9 no.1
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    • pp.1-7
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    • 1997
  • 다량의 방사선에 피폭되는 경우 인체에 해로운 영향을 미치는 것은 틀림이 없으나 미량의 방사선인 경우에는 다량의 방사선인 경우와 다른 효과를 나타내며 심지어 정반대의 영향을 나타내기도 한다고 볼 수 있으며 여러 역학조사에서 이러한 사실이 증명되고 있다. 1991년의 국제방사선방어기구(ICRP) 보고서 및 1994년의 UNSCEAR 보고서는 미량의 방사선에 대한 적응반응을 인정하고 있다. 일부 학자들은 소량의 방사선에 지속적으로 피폭(연간 1 rem)됨으로써 암사망률을 감소시킬 수 있다고 주장하면서 현재의 개념을 수정하여 피폭한계 및 법적 제한 등을 변경하여 환경방사능을 증가시킴으로써 향후 인류의 생활의 질을 향상시켜야 한다고 주장하고 있다.

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Change of FDG Uptake According to Radiation Dose on Squamous Cell Carcinoma of the Head and Neck (두경부종양에서 방사선조사량에 타른 FDG-PET의 변화양상)

  • Lee Sang-wook;Kim Jae-Seung;Im Ki Chun;Ryu Jin Sook;Lee Hee Kwan;Kim Jong Hoon;Ahn Seung Do;Shin Seong Soo;Yoon Sang Min;Song Siyeol;Park Jin-hong;Moon Dae Hyuk;Choi Eun Kyung
    • Radiation Oncology Journal
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    • v.22 no.2
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    • pp.98-105
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    • 2004
  • Purpose : To evaluate whether positron omission tomography (PET) with 2-[F-18]fluoro-2-deoxy-D-giucose(FDG) can be used to predict of early response to definitive aim radlotherapy (RT) in squamous cell carcinoma of the head and neck using response rate and locoreglonal control as study endpoints. Materials and Methods : Twenty-two patients with head and neck cancer underwent a FDG-PET study before RT, after a flrst dose of 45 Gy, and after a second dose on more 4han 70 Gy. Standard uptake value (SUV) was calculated for primary tumor (n=22) and neck lymph node (n:10). Attenuation corrected PET scans acquired 60 min after tracer injection were used for evaluation of FDG uptake In tumors. A quantitative FDG uptake index was expressed as Suvlean (corrected for iean body mass). The follow-up time was at least 5 months (range S-1 S months). Results : A total of 22 primary tumors and 10 metastatic lymph nodes were analyzed In FDG-PET. In the first PET study the mean SUVlean the primary tumors and nodes were 5.4 (SD, 2.5) and 4.6 (SD, 2.3), respectively. In the second PET, study peformed after 46 Gy RT the mean SUV in primary tumor and node decreased to 2.9 (SD, 1.9, p<0.001) and 1.7 (SD, 1.3) respectively. in the third PET study peformed at the full dose (more than 70 Gy), RT the mean SUV In the primary tumors and nodes decreased to 2.3 (SD, 1.5, p<0.001) and 1.5 (SD, 1 .1) respectively. Conclusions: FDG uptake In tumors showed a significant decrease after the 45 Gy and more than 70 Gy of RT for squamous cell carcinoma of the head and neck. Reduction of metabolic activity after 46 Gy of radiotherapy Is closely correlated with radiation response.

Modeling of Dual Head Gantry Radiotherapy System with Monte Carlo Simulation (듀얼 헤드 갠트리 방사선치료 시스템 설계를 위한 몬테칼로 시뮬레이션 연구)

  • Park, Seungwoo
    • Journal of radiological science and technology
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    • v.40 no.4
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    • pp.627-632
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    • 2017
  • In order to design a dual-head gantry radiotherapy system, the single head of LINAC was modeled using GATE as a preliminary study. The LINAC head was designed with VARIAN manufacturer's information. 6 MV photons were generated from the head and the photons w irradiated to a water phantom for beam evaluation. GATE simulation was segmented by two stages, the one was to generate X-ray spectrum and the other one was for irradiation X-ray to the water phantom. The quantitative results were described in Percentage depth dose and beam profile. Two field size conditions were employed as $5{\times}5$ and $10{\times}10cm^2$. After beam quality was verified, dual heads gantry radiotherapy system were simulated and they was compared to the single head of LINAC system in terms of dose deposition with in the phantom. The simulated LINAC head showed acceptable beam quality result for radiotherapy. The efficiency was calculated that deposited dose from dual heads was divided by the dose from single head. At all conditions, dual heads showed higher treatment efficiency. Efficiency was increased about 40 to 60%. Form the result, The dual head gantry system of new LINAC system will contribute to the practical radiotherapy of tumor and to reduce treatment time.