• 핵의학기술
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• 제18권1호
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• pp.158-162
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• 2014

공인된 기구에 의해 발급된 문서를 동반하는 인증표준물질은 특성값과 추정값의 신뢰정도를 나타내는 연계 불확도, 그리고 측정한 결과가 명시된 불확정 정도의 범위 내에서 국가 측정 또는 국제측정표준에 일치되도록 연속적으로 비교하고 교정하는 소급성을 제공하는 표준물질이다. 회수율 검사는 검체를 측정하여 얻은 값이 참값에서 얼마만큼 벗어났는지의 차이를 말하며 키트의 정확도를 반영한다. 이러한 인증표준물질을 가지고 회수율 검사를 하는 것은 체외 방사면역진단키트의 정확성을 보여주며 이러한 평가는 매우 중요하다. 인증표준물질은 NIBSC (National Institute for biological standard and control, United Kingdom)와 IRMM (Institute for Reference Materials and Measurements, Belgium)에서 구입하였고 검사 종목은 T4, Ferritin, PSA, Prolactin, AFP 그리고 TSH으로 총 6종목이다. T4는 IRMM의 표준물질을 사용하였고 나머지 종목은 NIBSC의 표준물질을 사용하였다. C-1 (저농도), C-2 (중농도), C-3 (고농도) 3 level로 제조하여 본원에서 사용하는 키트를 이용하여 4회 측정하였다. WHO 인증표준물질을 이용한 회수율 측정에서 T4 90%, Ferritin 88%, PSA 94%, Prolactin 99%, AFP 94%, TSH 93%였다. 6개 종목의 회수율 측정에서 88-99%로 양호한 결과를 보였다. 핵의학 체외진단키트의 정확성을 높이기 위해서 이 연구가 다른 검사실의 키트로 확장되어 검사가 되어야 하고 검사실간에도 교류가 필요하다. 인증표준물질을 이용한 체외진단키트의 회수율 평가가 앞으로도 지속되어야 하며 결과의 정확성은 환자의 만족의 증가로 이어질 것으로 기대한다.

• 한국안전학회지
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• 제33권6호
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• pp.144-156
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• 2018

Level 3 Probabilistic Safety Assessment (PSA) is performed for the risk assessment that calculates radioactive material dispersion to the environment. This risk assessment is performed with a tool of MELCOR Accident Consequence Code System (MACCS2 or WinMACCS). For the off-site consequence analysis of multi-unit nuclear power plant (NPP) accident, the single location (Center Of Mass, COM) method has been usually adopted with the assumption that all the NPPs in the nuclear site are located at the same COM point. It was well known that this COM calculation can lead to underestimated or overestimated radionuclide concentration. In order to overcome this underestimation or overestimation of radionuclide concentrations in the COM method, Multiple Location (ML) method was developed in this study. The radionuclide concentrations for the individual NPPs are separately calculated, and they are summed at every location in the nuclear site by the post-processing of radionuclide concentrations that is based on two-dimensional Gaussian Plume equations. In order to demonstrate the efficiency of the ML method, radionuclide concentrations were calculated for the six-unit NPP site, radionuclide concentrations of the ML method were compared with those by COM method. This comparison was performed for conditions of constant weather, yearly weather in Korea, and four seasons, and the results were discussed. This new ML method (1) improves accuracy of radionuclide concentrations when multi-unit NPP accident occurs, (2) calculates realistic atmospheric dispersion of radionuclides under various weather conditions, and finally (3) supports off-site emergency plan optimization. It is recommended that this new method be applied to the risk assessment of multi-unit NPP accident. This new method drastically improves the accuracy of radionuclide concentrations at the locations adjacent to or very close to NPPs. This ML method has a great strength over the COM method when people live near nuclear site, since it provides accurate radionuclide concentrations or radiation doses.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1998년도 춘계학술발표회논문집(1)
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• pp.899-905
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• 1998

The analysis priority makings the recommendation to reduce the total core damage frequency (CDF) of Wolsong nuclear Power Plant nits 2/3/4 was Performed in this paper. In order to derive the recommendation, the sensitivity analysis of CDF on which major contributors effect m performed based on the accident quantification results during Level 1 Probabilistic safety assessment (PSA). Priorities were ranked in tile way that compares the CDF reduction rate with efforts required to implement those recommendations using risk matrix

• 고신대학교 의과대학 학술지
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• 제33권3호
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• pp.391-395
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• 2018

We report a case of a patient with locally advanced prostate cancer who had only lymph node involvement without bone metastasis on F-18 FDG PET/CT. A 62-year-old Korean male was admitted to our hospital due to dysuria. His PSA level on admission was 79.35 ng/mL. A transrectal ultrasound-guided prostate biopsy confirmed prostate cancer and his Gleason score was 10 (5+5). F-18 FDG PET/CT demonstrated a hypermetabolic mass lesion with SUVmax 7.0 in the prostate and hypermetabolism with SUVmax 4.7 of the abdominal and pelvic lymph nodes. Tc-99m HDP bone scan showed no significant bone metastasis. The patient underwent hormonal therapy for 9 months. Follow-up F-18 FDG PET/CT showed significantly reduced size and FDG uptake in the prostate and abdominal and pelvic lymph nodes. In this case, treatment monitoring with F-18 FDG PET/CT showed decreased mass size and FDG uptake in the prostate and abdominal and pelvic lymph nodes.

• Journal of Radiation Protection and Research
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• 제20권2호
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• pp.103-115
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• 1995

계측이 간단하며 화학적 분리가 필요 없는 액체섬광계수법을 이용하여 일부 지하수 및 온천수중 $^{222}Rn$의 최적 분석조건을 검토하였다. $^{222}Rn$의 분석을 위한 최적 파형분석(PSA) 준위는 Optiphase HiSafe3 형광체 (Cocktail)에서 110, 그리고 톨루엔계열 형광체 (Toluene-based cocktail)에서는 90이었다. $^{222}Rn$의 계측효율은 Optiphase HiSafe3 형광체를 이용한 경우 ${\alpha}$영역에서의 계수효율은 유리용기는 282.2%, 테프론용기에서는 271.6%였으며, 톨루엔계열 형광체를 이용한 경우에는 유리용기와 테프론 용기에서 각각 262.3%, 247,5%였다. Optiphase HiSafe3 형광체와 테프론용기를 사용하여 60분간 계측하는 경우 ${\alpha}$-선 피크영역에서 $^{222}Rn$의 검출하한치는 $0.30Bq/{\iota}$였다. 또한, 본 연구에서 검토한 분석법은 일부 지하수 및 온천수중 $^{222}Rn$의 분석에도 응용되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4577-4580
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• 2012

Diagnostic and therapeutic strategies of prostate cancer may largely influenced by patients' age at presentation. This study is aimed to evaluate the characteristics, diagnostic and treatment strategies in prostate cancer patients in our centres. A cross-sectional analytic study of prostate cancer data in two main referral cancer centres, Cipto Mangunkusumo General Hospital and Dharmais National Cancer Centre from 1995-2010, was therefore performed. Patients were divided into 2 sub-populations; below 60 years (younger patients) and 75 years old and above (older patients). PSA levels, diagnostic modalities, Gleason score and therapeutic options were analysed for both and compared using bivariate analysis. 152 patients were <60 years and 210 were ${\geq}75$ years. There was no statistical difference in mean PSA level (797.9ng/mL vs 345.3 ng/mL, respectively; p>0.05) and diagnosis was made by biopsy in majority of patients in both groups (68.2% and 71.6% in younger and older groups respectively). Most presented with an advanced disease stage (65.1% and 66.0%, respectively) and there was no statistically significant difference in mean Gleason scores f (8.1 vs 7.7; p>0.05). Primary androgen deprivation therapy (PADT) was the main treatment for overall patients (48.0% and 50.7%, respectively). Radiotherapy and radical prostatectomy are the main therapeutic modalities for younger patients with local and locally advanced disease (39.6% and 35.4% respectively), while the majority of older patients with the same disease stage were treated with radiotherapy and PADT (45.8% and 39.0% respectively). Differences observed in treatment modalities were statistically significant (p<0.0003). We conclude that there is no difference in disease clinical aggressiveness of the two groups but significant differences were observed in therapeutic strategies utilised with younger and older patients.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3083-3088
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• 2012

We investigated the prognostic value of pituitary tumor transforming gene 1 (PTTG1) expression according to clinicopathological features among localized or locally advanced prostate cancer cases receiving hormone therapy. A retrospective study involved 64 patients receiving combined androgen blockade treatment was performed. PTTG1 expression was determined by immunohistochemical staining using initial needle biopsy specimens for diagnosis. Associations of PTTG1 with various clinicopathological features and disease-free survival were examined via uni- and multivariate analyses. No association between PTTG1 expression and clinical T stage, Gleason score, pretreatment PSA levels, risk groups was found (p =0.682, 0.184, 0.487, 0.571, respectively). Univariate analysis revealed that increased PTTG1 expression, T3 stage and high risk group were associated with increased risk of disease progression (p =0.000, 0.042, and 0.001), and high PSA level had a tendency to predict disease progression (p =0.056). Cox hazard ratio analysis showed that PTTG1 low expression (p =0.002), PTTG1 high expression (p =0.000) and high risk group (p =0.0147) were significantly related to decreased disease-free survival. In conclusion, PTTG1 expression determined by immunohistochemical staining in needle biopsy specimens for diagnosis is a negative prognostic factor for progression in localized or locally advanced prostate cancer receiving hormone therapy.

• 전기학회논문지
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• 제58권3호
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• pp.444-449
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• 2009

This paper introduces a method to establish performance criteria of the in-house power supply system in nuclear power plants. The performance criteria of the system is presented in terms of the number of function failures and amount of the out-of-service time that can be allowed commensurate with the probabilistic safety assessment results of the nuclear power plants. To obtain the performance criteria such as reliability and availability, the functions of the system were analyzed and probabilistic assessment results were utilized. This method provides quantitative guidelines in selecting and monitoring system functions to determine an adequate level of maintenance quality in order to ensure the probabilistic goals for the safety of the nuclear power plants.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2690-2701
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• 2022

In this paper, we select important fission products for the estimation of the source term during a severe accident of a PWR. The selection is based on the numerical results obtained from depletion calculations for the typical PWR fuel via the in-house code named DEGETION (Depletion, Generation, and Transmutation of Isotopes on Nuclear Application), release fractions of the fission products derived from NUREG-1465, and effective dose conversion coefficients from ICRP 119. Then, for the selected fission products, we obtain the adjoint solutions of the Bateman equations for radioactive decay in order to determine the importance of precursors producing the aforementioned fission products via radioactive decay, which would provide insights into the assumption used in MACCS 2 for a level 3 PSA analysis in which up to six precursors are considered in the calculations of radioactive decays for the fission product after release from the reactor.

• 한국방사선학회논문지
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• 제3권2호
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• pp.5-10
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• 2009

심근영상의 SPECT(Single Photon Emission Computed tomography)검사는 감마선을 방출하는 방사성의약품을 환자에게 정맥주사한 후 이 의약품이 심장에 고루 퍼지면 관심부위를 촬영하여 질병으로 인한 변화를 컴퓨터를 이용하여 진단하는 검사법이다. 기능적인 정보를 담고 있는 심근관류 영상은 비침습적인 심근질환 검사에 유용한 방법이지만, 물리적 인자들에 의해 잡음과 낮은 해상도는 판도하는데 어려움을 주게 된다. 본 논문은 심근영상을 레벨 셋 알고리즘을 이용하여 영상을 분할하고 분할된 영역을 3차원으로 구현하여 판독에 도움을 주는 방안을 제안하였다. 판독의 어려움을 해결하기 위하여 레벨 셋을 이용하여 관심부위인 좌심실 영역을 분할하였고 분할된 영역을 3차원영상으로 모델링하였다.