• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.1
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• pp.21-28
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• 2021

Purpose Brown fat, or brown adipose tissue (BAT), is involved in non-shivering thermogenesis and creates heat through glucose metabolism. BAT activation occurs stochastically by internal factors such as age, sex, and body mass index (BMI) and external factors such as temperature and environment. In this study, as a retrospective, electronic medical record (EMR) observation study, statistical analysis is conducted to confirm BAT activation and various factors. Materials and Methods From January 2018 to December 2019, EMR of patients who underwent PET/CT scan at the National Cancer Center for two years were collected, a total of 9155 patients were extracted, and 13442 case data including duplicate scan were targeted. After performing a univariable logistic regression analysis to determine whether BAT activation is affected by the environment (outdoor temperature) and the patient's condition (BMI, cancer type, sex, and age), A multivariable regression model that affects BAT activation was finally analyzed by selecting univariable factors with P<0.1. Results BAT activation occurred in 93 cases (0.7%). According to the results of univariable logistic regression analysis, the likelihood of BAT activation was increased in patients under 50 years old (P<0.001), in females (P<0.001), in lower outdoor temperature below 14.5℃ (P<0.001), in lower BMI (P<0.001) and in patients who had a injection before 12:30 PM (P<0.001). It decreased in higher BMI (P<0.001) and in patients diagnosed with lung cancer (P<0.05) In multivariable results, BAT activation was significantly increased in patients under 50 years (P<0.001), in females (P<0.001) and in lower outdoor temperature below 14.5℃ (P<0.001). It was significantly decreased in higher BMI (P<0.05). Conclusion A retrospective study of factors affecting BAT activation in patients who underwent PET/CT scan for 2 years at the National Cancer Center was conducted. The results confirmed that BAT was significantly activated in normal-weight women under 50 years old who underwent PET/CT scan in weather with an outdoor temperature of less than 14.5℃. Based on this result, the patient applied to the factor can be identified in advance, and it is thought that it will help to reduce BAT activation through several studies in the future.

• 대한예방의학회:학술대회논문집
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• 2002.02a
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• pp.65-80
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• 2002

• Journal of the Korean hospital association
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• v.31 no.5 s.279
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• pp.43-53
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• 2002

• Hospice
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• s.71
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• pp.3-8
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• 2021

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.97-105
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• 2018

Purpose : Proton Therapy using Bragg-peak, because it has distinct characteristics in providing maximum dosage for tumor and minimal dosage for normal tissue, a medical imaging system that can quantify changes in patient position or treatment area is of paramount importance to the treatment of protons. The purpose of this research is to evaluate the usefulness of the algorithm by comparing the image matching through the set-up and in-house code through the existing dips program by producing a Matlab-based in-house registration code to determine the error value between dips and DRR to evaluate the accuracy of the existing treatment. Materials and Methods : Thirteen patients with brain tumors and head and neck cancer who received proton therapy were included in this study and used the DIPS Program System (Version 2.4.3, IBA, Belgium) for image comparison and the Eclipse Proton Planning System (Version 13.7, Varian, USA) for patient treatment planning. For Validation of the Registration method, a test image was artificially rotated and moved to match the existing image, and the initial set up image of DIPS program of existing set up process was image-matched with plan DRR, and the error value was obtained, and the usefulness of the algorithm was evaluated. Results : When the test image was moved 0.5, 1, and 10 cm in the left and right directions, the average error was 0.018 cm. When the test image was rotated counterclockwise by 1 and $10^{\circ}$, the error was $0.0011^{\circ}$. When the initial images of four patients were imaged, the mean error was 0.056, 0.044, and 0.053 cm in the order of x, y, and z, and 0.190 and $0.206^{\circ}$ in the order of rotation and pitch. When the final images of 13 patients were imaged, the mean differences were 0.062, 0.085, and 0.074 cm in the order of x, y, and z, and 0.120 cm as the vector value. Rotation and pitch were 0.171 and $0.174^{\circ}$, respectively. Conclusion : The Matlab-based In-house Registration code produced through this study showed accurate Image matching based on Intensity as well as the simple image as well as anatomical structure. Also, the Set-up error through the DIPS program of the existing treatment method showed a very slight difference, confirming the accuracy of the proton therapy. Future development of additional programs and future Intensity-based Matlab In-house code research will be necessary for future clinical applications.

• The Journal of Korean Society for Radiation Therapy
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• v.31 no.1
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• pp.43-49
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• 2019

Purpose : We apply the Layered Rescanning PBS designed to complement the Pencil Beam Scanning(PBS), which is vulnerable to moving organs with the Moving Phantom, and compare the homogeneity with the single scan PBS. Methods and materials: Matrix X (IBA, Belgium) and Moving Phantom (standard imaging, USA) were used. A dose of 200 cGy was measured in the AP direction on a hypothetical tumor $10{\times}10{\times}5cm$. The plan type was planned as 4 kinds of sinlge scan PBS, rescan number 4, 8, 12 times. Were measured three times for each types. During the measurement, the respiratory cycle of the Moving Phantom was generally set to 4 seconds per cycle, and the movement radius in the S-I direction was set to 2 cm. In addition, beam on time was measured. Results : The mean values of $D_{max}$ in the PTV were $246.47{\pm}18.8cGy$, $223.43{\pm}8.92cGy$, and $222.47{\pm}7.7cGy$, $213.9{\pm}6.11cGy$ and the mean values of $D_{min}$ were $165.53{\pm}4.32cGy$, $173.13{\pm}11.94cGy$, $184.13{\pm}8.04cGy$, $182.67{\pm}4.38cGy$ and the mean values of $D_{mean}$ $192.77{\pm}6.98cGy$, $196.7{\pm}4.01cGy$, $198.17{\pm}4.96cGy$, $195.77{\pm}3.15cGy$ respectively. As the number of rescanning increased, the Homogeneity Index converged to 1. The beam on time was measured as 2:15, 3:15, 4:30, 5:37 on average. In the measurement process, in the low dose layer of the MU, the problem was found that it was not rescanned as many times as the set number of rescan. Conclusions : In the treatment of tumors with long-term movements, the application of layered rescanning PBS showed a more uniform dose distribution than single scan PBS. And as the number of rescan increase, the distribution of homogeneity is uniform. Compared with single scan plan and 12 rescan plan, HI value was improved by 0.32. Further studies are expected to be applicable to patients who can not be treated with respiratory synchronous radiation therapy.

• Journal of Digestive Cancer Research
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• v.6 no.2
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• pp.64-68
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• 2018

Pancreatic ductal adenocarcinoma is a dismal prognosis and 5^th leading cause of cancer related death in Korea. A large proportion of patients are diagnosed at advanced or metastatic stage. Therefore systemic chemotherapy has become the mainstay of treatment for pancreatic cancer. For most patients advanced or metastatic pancreatic cancer that has a good Eastern Cooperative Oncology Group performance status (ECOG PS) 0 or 1, we can recommend for FOLFIRINOX (leucovorin, 5-fluorouracil [5-FU], irinotecan and oxaliplatin) and gemcitabine plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel). Currently, steps towards improved therapeutic efficacy of palliative chemotherapy have been made by introducing these regimens. For patients with an ECOG PS of 2, gemcitabine monotherapy or S1 alone is recommended. The second-line therapy for patients initially treated with gemcitabine-based chemotherapy includes provide FOLFOX (leucovorin, 5-FU, and oxaliplatin), capecitabine plus oxaliplatin, and 5-FU plus liposomal irinotecan. The gemcitabine-based chemotherapy is a reasonable choice for patients treated with FOLFIRINOX. Currently, studies on selecting patients for biomarkers related to molecular biologic features of tumors are underway for the realization of precise medicine, and the development and verification of preclinical models for the development of new therapeutic agents are being carried out continuously.

• 건강소식
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• v.27 no.9 s.298
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• pp.18-19
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• 2003

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.191-199
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• 2018

Purpose : In this study, we evaluated the usefulness of colloid gel(slime) as a compensator for irregular patient surfaces in radiation therapy. Materials and Methods : For this study, colloid gel suitable for treatment was made and four experiments were conducted to evaluate the applicability of radiation therapy. Trilogy(Varian) and CT(SOMATOM, Siemens) were used as treatment equipment and CT equipment. First, the homogeneity according to the composition of colloid gel was measured using EBT3 Film(RIT). Second, the Hounsfield Unit(HU) value of colloid gel was measured and confirmed by CRIS phantom, Eclipse RTP(Eclipse 13.1, Varian) and CT. Third, to measure the deformation and degeneration of colloid gel during the treatment period, it was measured 3 times daily for 2 weeks using an ion chamber(PTW-30013, PTW). The fourth experiment was compared the treatment plan and measured dose distributions using bolus, rice, colloid gel and additional, dose profiles in an environment similar to actual treatment using our own acrylic phantom. Result : First experiment, density of the colloid gel cases 1, 2 and 3 was $1.02g/cm^3$, $0.99g/cm^3$ and $0.96g/cm^3$. When the homogeneity was measured at 6 MV and 9 MeV, case 1 was more homogeneous than the other cases, as 1.55 and 1.98. In the second experiment, the HU values of case 1, 2, 3 were 15 and when the treatment plan was compared with the measured doses, the difference was within 1 % at all 9, 12 MeV and a difference of -1.53 % and -1.56 % within the whole 2 % at 6 MV. In the third experiment, the dose change of colloid gel was measured to be about 1 % for 2 weeks. In the fourth experiment, the dose difference between the treatment plan and EBT3 film was similar for both colloid gel and bolus, rice at 6 MV. But colloid gel showed less dose difference than bolus and rice at 9 MeV. Also, dose profile of colloid gel showed a more uniform dose distribution than the bolus and rice. Conclusion : In this study, the density of colloid gel prepared for radiation therapy was $1.02g/cm^3$ similar to the density of water, and alteration or deformation was not observed during the radiotherapy process. Although we pay attention to the density when manufacturing colloid gel, it is sufficient in that it can deliver the dose uniformly through the compensation of the patient's body surface more than the bolus and rice, and can be manufactured at low cost. Further studies and studies for clinical applications are expected to be applicable to radiation therapy.

• Korean Journal of Digital Imaging in Medicine
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• v.17 no.1
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• pp.19-31
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• 2015

최근 우리나라의 암 발생률은 꾸준히 증가추세에 있고 그 중에서도 전립선암은 갑상선암을 제외했을 때 남성에서 가장 높은 증가 추세를 보이고 있는 암이다. 전립선암은 그 동안 선진국에서 주로 발병하는 것으로 알려진 암 종이지만 서구화된 식습관과 생활 행태 변화로 인하여 국내에서도 발생률이 증가하는 것으로 추정하고 있다. 따라서 국내 환경에 맞는 내장 지방 분포와 같은 정확한 비만도 측정을 통해 우리나라에서 증가율 1위를 보이고 있는 전립선암 발생의 원인 관계를 찾고자 한다. 본 연구는 환자와 정상군 비교를 하는 환자-대조군 연구이고 본 연구를 위하여 임상시험 윤리위원회 (IRB) 승인을 받았다 (NCC2014-0124). 환자군은 2014년 8월 1일부터 2015년 1월 6일 까지 국립암센터를 방문하여 전립선암을 진단받고 수술과 항암치료 그리고 방사선 치료를 시작하지 않은 초진을 대상으로 하였고, 정상군은 2009년 11월부터 2014년 9월 30일까지 공단검진을 목적으로 국립암센터를 방문한 정상인을 대상으로 하였다. 전립선암 연구는 환자 총 52명에 평균 66세 (51 - 82세)이고 정상군은 총 50명에 평균 64세 (59 - 75세) 이다. 모든 연구 대상자들의 생활 요인 평가를 위하여 암 가족력, 흡연, 음주 상태, 운동, 등을 추가적으로 설문 조사하였다. MRI 영상의 배꼽 주위에서의 내장 지방과 피하지방을 전용 분석 컴퓨터를 활용하여 측정 하였다. 복부비만율은 환자군과 정상군에서뿐만 아니라 (p = 0.03), 전립선암 악성도와 (Gleasonscore; p = 0.001)도 통계적 차이를 나타냈다. 하지만 BMI 결과와는 전립선암 발생과 악성도에서 무관함을 보인 것에 반해 허리둘레는 전립선암의 발생에 영향을 미치는 결과를 나타났다. 한편 전립선암의 또 다른 악성도 지표인 PSA는 비만 측정치와의 상관성이 Gleason score와 보다 대체적으로 낮게 나타났다. 학력, 운동량, 흡연, 음주 상태와 같은 생활 특성에 따른 전립선암 발생의 영향 관계는 뚜렷하지 않았다. 결론적으로 본 연구를 통해서 전립선암의 발생 위험도와 악성도 지표로 복부 비만도가 유용함을 나타냈고 간단한 신체 계측 지표 활용으로는 BMI보다 허리둘레 측정치가 더 암 발생의 연관성이 높음을 보였다.