유방 보존술 후 내유림프절을 포함하는 방사선치료 기법에 관한 연구

정경근(Kyoungkeun Jeong),심수정(Su Jung Shim),유세환(Sei Hwan You),김용배(Yong Bae Kim),금기창(Ki Chang Keum),김종대(Jong Dae Kim),서창옥(Chang Ok Suh) 대한방사선종양학회 2009 Radiation Oncology Journal Vol.27 No.1

목 적: 유방암 환자에서 부분적 유방절제술 후 내유림프절(internal mammary lymph node: IMN)을 포함하여 방사선 치료하기 위한 최적의 치료 방법을 찾고자 하였다. 대상 및 방법: 초기 유방암으로 부분적 유방절제수술을 받고 방사선치료를 받은 10명의 환자들의 CT simulation 데이터를 얻어서 각 환자들에서 4가지 치료방법을 계획하고 평가하였다. 5명은 오른쪽 유방을, 나머지 5명은 왼쪽 유방을 치료 받았다. 각 환자에서 유방, 쇄골 상부 림프절(supraclavicular lymph node: SCL), IMN (위쪽 3개의 늑골사이에 있는 림프절만 포함)을 조사하는 치료계획을 하였다. IMN을 조사하는 방법으로 4가지 방식, 즉 표준적인 접선방향 치료(Standard Tangential Field: STF), 확장접선치료 방법(Wide Tangential Field, WTF), 부분 확장접선치료방법(Partially Wide Tangential Field: PWT), 광자와 전자를 혼합한 방법(Photon-Electron Mixed 5 Field: PEM)을 사용하였다. SCL field는 3 cm에, 유방조직은 중심점에 50.4 Gy를 28회에 나누어 치료하도록 처방하였다. 결 과: 각각의 치료 기법은 환자마다 차이는 있었으나 뚜렷한 특징을 보였다. 유방조직의 선량은 각 치료 기법마다큰 차이가 없었다. IMN는 치료 기법마다 차이가 있으나 STF를 제외한 세 가지 방법은 대체로 IMN을 잘 감싸고 있었다. 왼쪽 유방을 치료하는 경우 심장이 받는 선량은 고선량 영역에서는 WTF, PWT, PEM, STF의 순으로 많은 체적에 선량을 받았으며 낮은 선량 영역에서는 PEM, WTF, PWT, STF의 순이었다. 동측 폐의 선량 역시 마찬가지의 순서를 보였다. Lyman-Kutcher-Burman model에 의한 방사선 폐렴에 대한 NTCP는 개인별 편차가 컸다. 대체로STF가 가장 작고 PWT가 다음이었으나 PEM와 WTF의 경우는 환자마다 큰 차이를 보였다. 결 론: 환자들의 다양한 체형에도 불구하고 IMN를 포함하여 치료하는 경우 PWT가 폐와 심장의 조사선량을 줄이고 IMN에 표적선량을 전달하는데 적합한 것으로 생각된다. Purpose: This study was designed to determine the optimum radiotherapy technique for internal mammary node (IMN) irradiation after breast-conserving surgery. Materials and Methods: We selected ten cases of early stage partial mastectomy for plan comparison. Five of the patients were treated to the right-side breast and the rest of the patients were treated to the left-side breast. For each case, four different treatment plans were made to irradiate the entire breast, IMNs and supraclavicular lymph nodes (SCLs). The four planning techniques include a standard tangential field (STF), wide tangential field (WTF), partially wide tangential field (PWT) and a photon-electron mixed field (PEM). We prescribed a dose of 50.4 Gy to the SCL field at a 3 cm depth and isocenter of the breast field. Results: The dose distribution showed clear characteristics depending on the technique used. All of the techniques covered the breast tissue well. IMN coverage was also good, except for the STF, which was not intended to cover IMNs. For the cases of the left-side breasts, the volume of the heart that received more than 30 Gy was larger (in order) for the WTF, PWT, PEM and STF. For radiation pneumonitis normal tissue complication probability (NTCP), the PWT showed the best results followed by the STF. Conclusion: Despite the variety of patient body shapes, the PWT technique showed the best results for coverage of IMNs and for reducing the lung and heart dose.

Dissolution of Magnesium from Serpentine Mineral in Sulfuric Acid Solution

Yoo, Kyoungkeun,Kim, Byung-Su,Kim, Min-Seuk,Lee, Jae-chun,Jeong, Jinki The Japan Institute of Metals 2009 MATERIALS TRANSACTIONS Vol.50 No.5

<P>As the volume of CO<SUB>2</SUB>, one of greenhouse gases linked to global warming, in the atmosphere increases, there has been an increasing interest in CO<SUB>2</SUB> sequestration. Aqueous carbonation, which involves the extraction of Mg from serpentine minerals and the subsequent carbonation reaction with CO<SUB>2</SUB> to form the geologically stable mineral MgCO<SUB>3</SUB>, has been proposed as a promising CO<SUB>2</SUB> sequestration technology. This study investigates the dissolution of Mg from serpentine mineral in H<SUB>2</SUB>SO<SUB>4</SUB> solution. The study is part of a major research project aimed at developing an effective CO<SUB>2</SUB> sequestration technology using the serpentine mineral which is readily available in Korea. Complete dissolution of Mg from natural serpentine was achieved in 30 min at a temperature of 90°C under 0.5 M H<SUB>2</SUB>SO<SUB>4</SUB>. The rate of dissolution of Mg was independent of the agitation speed at speeds above 300 rpm. The fraction of Mg dissolved from milled serpentine was found to be a little higher than that from natural serpentine up to 70°C in 0.5 M H<SUB>2</SUB>SO<SUB>4</SUB>. The Jander equation was used to explain the dissolution rate data. The rate of Mg dissolution seemed to be limited by diffusion through the thin channels formed between the silica layers in the serpentine particles.</P>

Thermodynamic stability and formation kinetics of CHClF₂ hydrates in the presence of NiCl₂

Woo, Yesol,Jeong, Jae Hak,Lee, Jong-Won,Park, Jeasung,Cha, Minjun,Kim, Dongseon,Yoo, Kyoungkeun,Yoon, Ji-Ho Elsevier 2019 Chemical engineering science Vol.202 No.-

<P><B>Abstract</B></P> <P>A hydrate-based technology is suggested for the desalination of industrial effluents, especially electroplating effluents including NiCl<SUB>2</SUB>. To decrease the required energy for operating a hydrate-based desalination (HBD) process, chlorodifluoromethane (CHClF<SUB>2</SUB>) was used as a guest for hydrate formation at relatively mild conditions. The phase equilibria of CHClF<SUB>2</SUB> hydrates formed in aqueous NiCl<SUB>2</SUB> solutions were investigated to identify the effect of NiCl<SUB>2</SUB> on the thermodynamic stability of CHClF<SUB>2</SUB> hydrates. The dissociation phase boundary of CHClF<SUB>2</SUB> hydrates in the presence of NiCl<SUB>2</SUB> was shifted to higher pressures and lower temperatures as the salinity of aqueous solutions increased. To confirm the feasibility of NiCl<SUB>2</SUB> separation from wastewaters via the HBD process, X-ray diffraction and Raman spectroscopic measurements were performed. The results showed that the Ni<SUP>2+</SUP> and Cl<SUP>−</SUP> ions did not participate in the hydrate framework, which revealed that the HBD process could be used to remove NiCl<SUB>2</SUB> from effluents. The formation kinetics of CHClF<SUB>2</SUB> hydrates were analyzed by a new kinetic model adopting transient time-dependent apparent rate constants, which significantly depends on the sub-cooling temperature and the concentration of NiCl<SUB>2</SUB> in the aqueous solutions. Thermodynamic approximations regarding the Ni<SUP>2+</SUP> and Cl<SUP>−</SUP> ion exclusion from the clathrate framework and the full occupancy of CHClF<SUB>2</SUB> molecules in the large cages of structure I clathrate hydrate were confirmed by comparing the calculated Ni<SUP>2+</SUP> concentrations in the liquid phase in equilibrium with CHClF<SUB>2</SUB> clathrate hydrates with the experimental measurements. These results provide good information for separating metal ions from wastewater streams by HBD processes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hydrate-based desalination is developed to separate metal ions from wastewater. </LI> <LI> Metal ions cannot be trapped in the clathrate hydrate framework. </LI> <LI> Formation kinetics of clathrate hydrates depends on the concentration of metal ions. </LI> </UL> </P>

A Comparative Planning Study of Step-and-shoot IMRT versus Helical Tomotherapy in a Model Patient

김용남,김수곤,Kyoungkeun Jeong,이창걸,금기창,이익재,조재호 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.7

In order to assess the potential benefit of being able to use non-coplanar beams in a step-andshootintensity-modulated radiotherapy (ssIMRT) differently from helical tomotherapy (HT), weperformed a comparative planning evaluation in a model patient whose clinical target volumesenclosed critical normal tissue lying in the same plane. A patient with extensively relapsed malignantlymphoma in the circumferential chest wall was selected for comparison. Multiple, separated grosstumors were delineated, and the clinical target volume included the circumferential chest wallcontaining gross tumor volumes so that the critical organ, the right lung was fully enclosed. Threetypes of plans were analyzed; the first one was ssIMRT using only coplanar beams, the second wasssIMRT using non-coplanar beams, and the third was HT. The obtained results showed that dosehomogeneity inside the gross tumor volume was better in the case of HT than noncoplanar ssIMRTand coplanar ssIMRT. However, the volume fraction of the right lung receiving a high dose wasmuch smaller in the noncoplanar ssIMRT. As far as the dose to the clinical target volume (CTV)fully enclosing the right lung is concerned, not only the dose coverage of the CTV but also the dosehomogeneity and conformity in the noncoplanar ssIMRT was better than in both of HT and thecoplanar ssIMRT. We can conclude that appropriate isodose coverage for a complex target, whichfully encloses a critical organ lying in the same plane, can be achieved by using a non-coplanarbeam arrangement with no enforced penalty of higher dose to a critical organ.

A Study on Optimization of Photoneutron Shielding in a Medical Accelerator Room by Using Monte Carlo Simulation

Kim, Yong Nam,Choi, Sang Hyun,Jeong, Kyoungkeun,Kim, Joo Young,Lee, Chang Geol,Seong, Jinsil,Kim, Chan Hyeong Informa UK (Taylor Francis) 2008 Journal of nuclear science and technology Vol.45 No.suppl5

Bacterial Cyanide Generation in the Presence of Metal Ions (Na⁺, Mg²⁺, Fe²⁺, Pb²⁺) and Gold Bioleaching from Waste PCBs

Tran, Chi Dac,Lee, Jae-Chun,Pandey, Banshi Dhar,Jeong, Jinki,Yoo, Kyoungkeun,Huynh, Trung Hai The Society of Chemical Engineers, Japan 2011 Journal of chemical engineering of Japan Vol.44 No.10

<P>As an alternative using cyanide chemicals for gold extraction, the application of a cyanogenic bacterium <I>viz.</I> <I>Chromobacterium violaceum</I> (<I>C. violaceum</I>) in YP medium has been investigated. The catalytic roles of metal ions such as Na<SUP>+</SUP>, Mg<SUP>2+</SUP>, Fe<SUP>2+</SUP>, and Pb<SUP>2+</SUP>, as well as the effect of Na<SUB>2</SUB>HPO<SUB>4</SUB> nutrient addition on the cyanide generation efficiency of the bacterium in this medium have been elucidated. While MgSO<SUB>4</SUB> and FeSO<SUB>4</SUB> added to the medium were equally effective for cyanide generation, improved efficiency was obtained in the presence of Na<SUB>2</SUB>HPO<SUB>4</SUB> and Pb(NO<SUB>3</SUB>)<SUB>2</SUB>. In order to examine the effectiveness of <I>C. violaceum</I> cultured in YP medium for the generation of cyanide ions, the dissolution of gold and copper from waste mobile phone printed circuit boards (PCBs), a good source of gold and copper in alkaline conditions, was tested at 30°C, for various pH values and metal ion contents. Gold leaching was found to be 11% in 8 d at pH 11.0 in presence of 4.0 × 10<SUP>−3</SUP> mol/L MgSO<SUB>4</SUB>, whereas; copper recovery was high (11.4%) at pH 10.0. Addition of 1.0 × 10<SUP>−2</SUP> mol/L Na<SUB>2</SUB>HPO<SUB>4</SUB> and 3.0 × 10<SUP>−6</SUP> mol/L Pb(NO<SUB>3</SUB>)<SUB>2</SUB> to the YP medium increased copper leaching to 30.3% and 38.1%, respectively, at pH 10.0 in 8 d. However, this effect was not observed for gold leaching.</P>

Optimal Radiation Port Arrangements for Hepatic Tumor using 3-dimensional Conformal Radiotherapy Planning

Ik Jae Lee,Jinsil Seong,Su Jung Shim,Kyoungkeun Jeong,Kwang Hwan Cho 대한방사선방어학회 2006 방사선방어학회지 Vol.31 No.4

Performance of Double GEM and Triple GEM

Sanghyo Han,Do-Hyung Kim,Heedong Kang,Hyosung Cho,Jang-Min Han,Kyoungkeun Jeong,Sangmook Kang,Tae-Hoon Lee,Yongkyun Kim,Yong-Sub Cho,Young-Jun Kim 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.5

The operation of a double GEM and a triple gas electron multiplier (GEM) was examined in several gas mixtures, including Ar/Isobutane, Ar/CO2, and Ar/N2. In the double GEM and the triple GEM detectors, large gains of about 5 104 and 6 105, respectively, were obtained for the Ar/Isobutane mixture. The optimum value of the transfer eld and the dependence of the collection current on the drift, transfer, and collection field strengths for the GEM voltage sharing in the double GEM are discussed. A lower operation voltage and gain limit are also reported for the case of a triple GEM.

수모세포종의 방사선치료 후 전두엽하방 재발된 환자에서 원인 분석 및 구제 치료

조재호(Jae Ho Cho),금웅섭(Woong Sub Koom),이창걸(Chang Geol Lee),김경주(Kyoung Ju Kim),심수정(Su Jung Shim),박진호(Jino Bak),정경근(Kyoungkeun Jeong),김태곤(Tae-Gon Kim),김동석(Dong Seok Kim),최중언(Joong-Uhn Choi),서창옥(Chang Ok Su 대한방사선종양학회 2004 Radiation Oncology Journal Vol.22 No.3

목 적: 두개척수조사(Craniospinal irradiation) 후 전두엽 하방에서 재발(Subfrontal recurrence) 한 수모세포종 두 예를 경험하고, 방사선치료 측면에서 재발의 원인을 분석하고자 하였으며, 효과적인 구제 치료 방법을 모색하고자 하였다. 대상 및 방법: 두 예 모두 고위험군(T3bM1, T3bM3) 수모세포종으로 수술, 항암화학제 및 방사선 병합요법을 시행 받았으며, CT-Simulation으로 방사선치료계획이 이루어졌다. 한 예는 방사선치료 후 16개월에 재발하여 구제수술을 시행하고, 세기조절방사선치료로 30.6 Gy의 방사선을 재조사하였다. 다른 한 예는 12개월에 재발하여 구제수술만 시행하였다. 재발인자 확인을 위해 초기 방사선치료 시 사용되었던 모의치료사진을 확인하였고, 안구차폐의 과다 여부 및 가능한 원인 인자의 분석과 재발을 방지하기 위한 대안을 찾고자 하였다. 한예에서 방사선재조사에 대한 부담과 주변 중요정상장기의 인접성 때문에 전두엽하방재발 종양에 대한 구제치료로서 세기조절방사선치료를 계획하였으며, 표적체적에 대해서 7문 조사, 평균선량 30.6 Gy (1.8 Gy 분할, 최대선량의 85%)를 처방하고, 주변 정상중요장기인 시신경은 평균선량을 25 Gy, 안구는 10 Gy로 제한하였다. 결 과: 두 예 모두에서 모의치료사진상 정상장기 보호를 위한 안구차폐과다로 인한 전두엽하방 표적체적 일부에서의 저선량점을 확인할 수 있었다. CT-Simulation 상에서 automatic organ drawing 기능을 이용하여 전뇌와 안구의 외측 경계를 모의치료사진 화면에 같이 올릴 경우 차폐의 적절성을 판단하기가 더 용이하였다. 세기조절방사선치료계획 결과 표적체적에는 평균선량 31.1 Gy, 최대선량 36 Gy, 좌측 및 우측 시신경의 평균선량은 각각 13.9 Gy와 14.7 Gy, 좌우측 안구의 평균선량은 각각 5.5 Gy와 6.9 Gy로 우수한 치료계획을 획득하였다. 구제치료로 수술 및 세기변조방사선치료를 시행한 환자는 이후 방사선치료에 의한 부작용 없이 1년 간 무병상태이다. 결 론: 수모세포종의 전두엽하방 재발을 방지하기 위한 노력으로 두개척수조사 시 전두엽하방 및 체판 부위에 대한 각별한 주의를 기울여 차폐를 실시하여야 하겠고, 일단 재발하여 방사선재조사의 필요가 있는 경우 주변정상장기와의 방사선 선량 차이를 극대화할 수 있는 세기조절방사선치료를 통해 방사선치료 부작용의 부담을 줄일 수 있을 것으로 기대된다. Purpose: Firstly, to analyze factors in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma. Secondly, to explore an effective salvage treatment for these relapses. Materials and Methods: Two patients who had high-risk disease (T3bM1, T3bM3) were treated with combined chemoradiotherapy. CT-simulation based radiation-treatment planning (RTP) was performed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. Results: Review of radiotherapy portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume. When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. Conclusion: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.

Internal Mammary Lymph Node Irradiation after Breast Conservation Surgery : Radiation Pneumonitis versus Dose­Volume Histogram Parameters

Joo Young Kim(김주영),Ik Jae Lee(이익재),Ki Chang Keum(금기창),Yong Bae Kim(김용배),Su Jung Shim(심수정),Kyoungkeun Jeong(정경근),Jong Dae Kim(김종대),Chang Ok Suh(서창옥) 대한방사선종양학회 2007 Radiation Oncology Journal Vol.25 No.4

목 적: 방사선 폐렴과 체적­선량 히스토그램(dose­volume histogram, DVH) 변수들 사이의 연관성을 평가하고, 내유림 프절이 포함된 유방암의 방사선치료에서 방사선 폐렴을 방지할 수 있는 실제적인 지침을 제공하고자 한다. 대상 및 방법: 부분유방절제술을 받은 초기 유방암 환자 20명이 본 연구에 포함되었다. 전체 유방, 상부쇄골림프절,내유림프절에 총 28회 50.4 Gy가 조사되었다. 방사선 폐렴은 방사선 영상에서의 폐 변화(radiological pulmonary change; RPC)와 증상이 있는 방사선 폐렴(symptomatic radiation pneumonitis)에 의해 평가되었다. DVH 변수들은 grade<2 RPC와 grade≥2 RPC로 나누어 비교되었다. 이 때, DVH 변수들은 평균 폐 선량(mean lung dose), V10 (10 Gy 이상 받는 폐의 백분율 부피), V20, V30, V40, 그리고 정상 조직 합병증 확률(normal tissue complication probability, NTCP)이다. 결 과: 20명의 환자 중 9명(45%)에서 grade 2 RPC가 발생하였고, 11명(55%)에서는 발생하지 않았다. 1명의 환자에서 grade 1의 증상이 있는 방사선 폐렴이 발생하였다. 단변량 분석에서 DVH 변수 중, NTCP가 두 RPC grade 군 간에 유의한 차이를 보여주고 있다 (p<0.05). Fisher의 정확한 검증(exact test)은 NTCP값 45%가 RPC의 threshold level로서 적합함을 보여준다. 결 론: 본 연구는 NTCP가 유방암의 내유림프절 방사선치료 후 RPC 예측인자 중 한가지로 쓰일 수 있음을 보여준다. 임상적으로 이는 NTCP 45% 이상에서 RPC가 발생하기 용이함을 의미한다. Purpose: To evaluate the association between radiation pneumonitis and dose-volume histogram parameters and to provide practical guidelines to prevent radiation pneumonitis following radiotherapy administered for breast cancer including internal mammary lymph nodes. Materials and Methods: Twenty patients with early breast cancer who underwent a partial mastectomy were involved in this study. The entire breast, supraclavicular lymph nodes, and internal mammary lymph nodes were irradiated with a dose of 50.4 Gy in 28 fractions. Radiation pneumonitis was assessed by both radiological pulmonary change (RPC) and by evaluation of symptomatic radiation pneumonitis. Dose-volume histogram parameters were compared between patients with grade <2 RPC and those with grade ≥2 RPC. The parameters were the mean lung dose, V10 (percent lung volume receiving equal to and more than 10 Gy), V20, V30, V40, and normal tissue complication probability (NTCP). Results: Of the 20 patients, 9 (45%) developed grade 2 RPC and 11 (55%) did not develop RPC (grade 0). Only one patient developed grade 1 symptomatic radiation pneumonitis. Univariate analysis showed that among the dose-volume histogram parameters, NTCP was significantly different between the two RPC grade groups (p<0.05). Fisher’s exact test indicated that an NTCP value of 45% was appropriate as an RPC threshold level. Conclusion: This study shows that NTCP can be used as a predictor of RPC after radiotherapy of the internal mammary lymph nodes in breast cancer. Clinically, it indicates that an RPC is likely to develop when the NTCP is greater than 45%.