• Radiation Oncology Journal
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• 제36권2호
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• pp.95-102
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• 2018

Purpose: To evaluate the prognostic value of $^{18}F$-fluorodeoxyglucose positron-emission tomography (FDG PET) with computed tomography (CT) before and during radiotherapy (RT) in patients with head and neck cancer. Methods: Twenty patients with primary head and neck squamous cell carcinoma were enrolled in this study, of whom 6 had oropharyngeal cancer, 10 had hypopharyngeal cancer, and 4 had laryngeal cancer. Fifteen patients received concurrent cisplatin and 2 received concurrent cetuximab chemotherapy. FDG PET/CT was performed before RT and in the 4th week of RT. The parameters of maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of the primary tumor were measured, and the prognostic significance of each was analyzed with the Cox proportional hazards model. Results: Higher TLG (>19.0) on FDG PET/CT during RT was a poor prognostic factor for overall survival (OS) (p = 0.001) and progression-free survival (PFS) (p = 0.007). In the multivariate analysis, TLG during RT as a continuous variable was significantly associated with OS and PFS rate (p = 0.023 and p = 0.016, respectively). Tumor response worse than partial remission at 1 month after RT was another independent prognostic factor for PFS (p = 0.024). Conclusions: Higher TLG of the primary tumor on FDG PET/CT during RT was a poor prognostic factor for OS and PFS in patients with head and neck cancer.

• Radiation Oncology Journal
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• 제31권4호
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• pp.260-266
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• 2013

A clear consensus has not been established regarding the best treatment for solitary bone metastasis. Here, we reviewed the medical records of patients with a controlled primary malignancy who had only solitary spine metastasis without metastasis to the extraspinal bone or viscera and underwent treatment between April 2007 and December 2012 with stereotactic body radiosurgery using CyberKnife, with a total dose of 24 Gy in three to four fractions. During that time, there were only four cases. This was effective in each case, and all the four patients had no local failure and remained alive at a median follow-up of 68 months (range, 64 to 80 months). Although our experience is limited, this study suggests that stereotactic body radiotherapy could be a feasible, safe, effective, and noninvasive alternative treatment for solitary spine metastasis in patients who are medically inoperable or unsuitable for surgery.

• Radiation Oncology Journal
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• 제4권1호
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• pp.51-53
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• 1986

부비동의 악성임파종은 매우 빈도가 적으나 방사선치료로 완치가 가능한 종양이다. 내원당시 병변은 부비동과 그 주위에 국한되어 있으며, 전신적인 임파종으로의 변환은 흔치 않다. 대부분 부비동 임파종은 병리조직학적으로 조직구성 임파종이다. 원발병소와 경구임파절의 방사선 치료가 가장 적절한 치료이며 $50\~70\%$의 생존율을 기대할 수 있다.

• 센서학회지
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• 제23권2호
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• pp.73-81
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• 2014

Silicon PIN diode radiation sensors and CMOS readout circuits were designed and fabricated in this study. The PIN diodes were fabricated using a 380-${\mu}m$-thick 4-inch n+ Si (111) wafer containing a $2-k{\Omega}{\cdot}cm$ n- thin epitaxial layer. CMOS readout circuits employed the driving and signal processes in a radiation sensor were mixed with digital logic and analog input circuits. The primary functions of readout circuits are amplification of sensor signals and the generation of the alarm signals when radiation events occur. The radiation sensors and CMOS readout circuits were fabricated in the Institute of Semiconductor Fusion Technology (ISFT) semiconductor fabrication facilities located in Kyungpook National University. The performance of the readout circuit combined with the Si PIN diode sensor was demonstrated.

• Nuclear Engineering and Technology
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• 제36권3호
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• pp.229-236
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• 2004

Radiation hardening is a multiscale phenomenon involving various processes over a wide range of time and length. We present a multiscale model for estimating the amount of radiation hardening in pressure vessel steel in the environment of a light water reactor. The model comprises two main parts: molecular dynamics (MD) simulation and a point defect cluster (PDC) model. The MD simulation was used to investigate the primary damage caused by displacement cascades. The PDC model mathematically formulates interactions between point defects and their clusters, which explains the evolution of microstructures. We then used a dislocation barrier model to calculate the hardening due to the PDCs. The key input for this multiscale model is a neutron spectrum at the inner surface of reactor pressure vessel steel of the Younggwang Nuclear Power Plant No.5. A combined calculation from the MD simulation and the PDC model provides a convenient tool for estimating the amount of radiation hardening.

• Radiation Oncology Journal
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• 제19권4호
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• pp.353-358
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• 2001

척수내 전이암은 암환자에서 매우 드문 합병증으로 증상이 있는 척수 전이암 중 $3.4\%$정도를 차지한다고 보고된 바 있다. 척수내 전이암 환자의 생존 기간은 매우 짧아서 2개월 이내인 경우가 대부분인데 그 이유는 신경학적으로 빨리 악화되고 뇌전이를 포함하여 여러 곳에 전이암이 동반되기 때문이다. 국내 문헌상 척수내 전이암에 대한 보고가 거의 없고 저자들이 경험한 두 증례는 서로 다른 임상 경과를 보였기에 문헌 고찰과 함께 보고하는 바이다. 원발암이 접형동암인 환자에서 척수내 전이암으로 인해 이차성 척수공동증을 동반한 증례는 세계 문헌상 세번째 증례이다. 한 증례는 증상이 서서히 진행되었고 척수에 방사선치료를 시행한 후 생존기간이 26개월이었고, 다른 증례는 증상이 매우 빠르게 진행되었고 생존기간이 훨씬 짧았다. 척수내 전이암도 신경학적 증상이 가역적인 상태에서 조기 진단이 내려진다면 더욱 효과적인 증상완화를 기대할 수도 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3571-3574
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• 2014

Background: Brain metastasis occurs when cancerous cells come from a known (or sometimes an unknown) primary tumor to the brain and implant and grow there. This event is potentially lethal and causes neurologic symptoms and signs. These patients are treated in order to decrease their neurologic problems, increase quality of life and overall survival. Materials and Methods: In this study we evaluated clinical characteristics of 206 patients with brain metastases referred to our center from 2004 to 2011. Results: The mean age was 53.6 years. The primary tumors were breast cancer (32%), lung cancer (24.8%), lymphoma (4.4%), sarcoma (3.9%), melanoma (2.9%), colorectal cancer (2.4%) and renal cell carcinoma (1.5%). In 16.5% of the patients, brain metastasis was the first presenting symptom and the primary site was unknown. Forty two (20.4%) patients had a single brain metastasis, 18 patients (8.7%) had two or three lesions, 87 (42.2%) patients had more than three lesions. Leptomeningeal involvement was seen in 49 (23.8%) patients. Thirty five (17%) had undergone surgical resection. Whole brain radiation therapy was performed for all of the patients. Overall survival was 10.1 months (95%CI; 8.65-11.63). One and two year survival was 27% and 12% respectively. Conclusions: Overall survival of patients who were treated by combination of surgery and whole brain radiation therapy was significantly better than those who were treated with whole brain radiation therapy only [13.8 vs 9.3 months (p=0.03)]. Age, sex, primary site and the number of brain lesions did not show significant relationships with overall survival.

• Radiation Oncology Journal
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• 제15권4호
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• pp.321-329
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• 1997

목적 : 두경부 암 환자에서 경부 림프절 전이 가능성이 높아지는 것은 원발병소의 해부학적위치 및 특성, 원발병소의 크기 즉 병기와 조직병리학적 종류 따라 영향을 받는다. 두경부 암 환자에서 경부 림프절의 전이 양상은 다른 나라에서 분석, 연구되어 있고, 현재 두경부 암 환자 치료와 처치를 이를 기조로 하여 사용한다. 그러나, 두경부 암 환자에 대한 경부 림프절 전이에 대한 우리나라 환자의 통계는 없어 이번 통계를 시행하게 되었다. 대상 및 방법 : 1981년 11월부터 1995년 12월까지 본 병원 방사선 종양학과에 내원한 환자중초사가 가능한 997명을 대상으로 하였다. 조사는 방사선 종양학과에 내원시 면밀한 경부 촉진과향께 컴퓨터 단층 촬영영상 상에서 확인을 하였다. 환자는 크게 경부 림프절 전이가 있는 군과 전이가 없는 군으로 나누었고, 경부 림프절의 병기는 미국 암 연합회에서 추천한 방식에 의하였다. 원발병소의 위치 및 주위로의 침윤 등은 면밀한 관찰과 촉진, 컴퓨터 단층 촬영 영상, 수술소견 및 조직병리학 소견을 참조하였다. 결 과 :방사선 종양학과에 방사선 치료를 위해 내원한 997명 중 416명$(42\%)$에서 경부 림프절 전이를 뽀였고, 581명$(58\%)$에서 전이를 보이지 않았다. 경부 림프절 전이를 보인 림프절의 병기분포를 관찰한 결과 다음과 같았다. Hl : 106$(25.5\%)$, N2a 100$(24\%)$, N2b :68$(16.4\%)$, N2c : 69$(16.6\%)$, N3 :73$(15\%)$. 두경부 암 환자에서 원발병소의 빈도는 다음과 같다. 후두암 : 283$(28.5\%)$, 부비동암 : 152$(18\%)$, 구인두암: 144$(14.5\%)$, 비인강암: In$(12\%)$, 구강암 :92$(9\%)$, 하인두암:71$(7\%)$, 타액선암:$58(6\%)$, 미지원발부위암:31$(3\%)$, 피부암: $14(2\%)$. 두경부 암 환자 중 가장 경부 림프절 전이가 높은 원발병소는 비인강암$(71\%)$으로 나타났고, 다음은 하인두암$(69\%)$, 구인두암$(64\%)$, 구강암$(39\%)$ 순이었다. 경부 림프절 전이를 보였던, 416명 중에서는 구인두암 92명$(22\%)$, 비인강암 8f명$(21\%)$, 후두암 79명$(19\%)$의 순이였다. 병리조직학적으로 가장 빈도가 높을 것은 편평상피암증으로 전체 환자 중 $65.4\%$을 차지하였고, 다음은 악성 림프종이 109명으로 $11\%$였다. 결론 : 두경부 암 환자에서 경부 림프절 전이의 양상이 외국 통계와 비교 매우 유사하게 나타났으며, 원발병소의 해부학적 특성에 따라 경부 림프절 전이가 좌우되며 원발병소의 병기가 진행됨에 따라 경부 림프절 전이 빈도도 증가 되며 또한 경부 림프절의 병기도 증가되는 것을 관찰 할 수 있었다.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1250-1253
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• 2024

Activity measurement of the primary circuit water of fission reactors is one method that can provide early detection of a damaged fuel assembly in the reactor core. This is an important aspect in the safe operation of the reactor and for radiation protection of staff. Radionuclides in the primary circuit water are produced by the activation of stable nuclides and the fission of fissile nuclides, mainly the isotope ²³⁵U. In the LVR-15 research reactor, measurement of the activity of the primary circuit water has been regularly undertaken since 1996. A water sample is taken from the primary circuit every week and the activities are measured four days later using gamma spectrometry. The results of these long-term measurements from 1996 to 2022 are presented. The activity time dependences of the individual radionuclides are discussed in relation to fuel assembly damage and for events connected to contamination of the water by objects inserted into the primary circuit during experiments carried out near the reactor core.

• 한국항공운항학회지
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• 제26권2호
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• pp.91-97
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• 2018

High-energy charged particles are comprised of galactic cosmic rays and solar energetic particles which are mainly originated from the supernova explosion, active galactic nuclei, and the Sun. These primary charged particles which have sufficient energy to penetrate the Earth's magnetic field collide with the Earth's upper atmosphere, that is $N_2$ and $O_2$, and create secondary particles and ionizing radiation. The ionizing radiation can be measured at commercial flight altitude. So it is recommended to manage radiation dose of aircrew as workers under radiation environment to protect their health and safety. However, it is hard to deploy radiation measurement instrument to commercial aircrafts and monitor radiation dose continuously. So the numerical model calculation is performed to assess radiation exposure at flight altitude. In this paper, we present comparison result between measurement data recorded on several flights and estimation data calculated using model and examine the characteristics of the radiation environment in the atmosphere.