• 제목/요약/키워드: initial dose control

검색결과 153건 처리시간 0.023초

고선량율(高線量率) 강내조사법(腔內照射法)을 이용(利用)한 자궁경암(子宮頸癌) 방사선(放射線) 치료(治療) (The Treatment of Uterine Cervical Cancer Using High Dose Rate Co-60 Sources)

  • 김귀언;서창옥;이도행;박창윤
    • Radiation Oncology Journal
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    • 제1권1호
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    • pp.95-102
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    • 1983
  • The radical treatment of uterine cervical cancer by interacavitary radium or cesium, in combination with teletherapy are well known. Although the result of such treatment should not give rise to complacency, problem of radiation exposure to medical staff had not been resolved. Fortunately, many attempts have been made to reduce this hazard, most of which take the form of afterloading applicators with a suitably shielded radioisotope. In order to avoid hazardous radiation exposure to staffs concerned with brachytherapy, RALS using high intensity source of Co-60, have been employed at Yonsei Cancer Center since May, 1979. It allows rectal and bladder doses to be kept low, while maintaining a satifactory usual dose distribution of the other type of applicators, and the short treatment time allow four or five patients to be treated per hour. It also removes much patient's discomfort and the difficulties of nursing these patients. Since the first introduction in Korea, over seven hundred cases with various stage of uterine cervical cancer have been treated on a radical basis at this center last 4 years. These authors have strongly attracted attention to the results in terms of local control rate, survival s and morbidity compared with those of conventional low dose rate radiotherapy. Retrospective interim analysis of data was preliminarily accomplished through the labored follow-up study of 340 cases treated during initial 2 years and the radiobiologic standpoint of high dose rate intracavitary irradiation will be discussed.

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Reirradiation with Robotic Stereotactic Body Radiotherapy for Recurrent Nasopharyngeal Carcinoma

  • Dizman, Aysen;Coskun-Breuneval, Mehtap;Altinisik-Inan, Gonca;Olcay, Gokce Kaan;Cetindag, Mehmet Faik;Guney, Yildiz
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3561-3566
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    • 2014
  • Background: Recurrent nasopharyngeal carcinoma (NPC) after previous radiotherapy is challenging. There is no standard approach for salvage treatment. Here we present toxicity and treatment results for recurrent NFC patients who underwent fractionated stereotactic radiotherapy (FSRT) as second line radiotherapy (RT). Materials and Methods: Between April 2009 and July 2012, 24 patients, with a male to female ratio of 3:1, were treated with CykerKnife$^{(R)}$ FSRT for recurrent NFC in our institution. Seven out of 24 patients had metastatic recurrent disease. Median age was 53 years (range, 20-70 years). Initial RT dose was 70Gy. The time period between initial RT and FSRT was a median of 33.2 months. The median prescription dose for FSRT was 30Gy (range, 24-30 Gy) in a median of 5 fractions (range, 4-6). Results: The median follow-up for all patients was 19.5 months (IQR: 12.2.-29.2 months). The locoregional control; progression free survival and overall survival (OS) rates for 1-, 2- and 3-year were 64%, 38%, 21%; 60%, 30%, 17% and 83%, 43%, 31%, respectively. Median OS for the entire cohort was 22 months (95% CI: 16.5-27.5). On multivariate analysis recurrent tumor stage was the only prognostic factor for OS (p=0.004). One patient exhibited grade III temporal lobe necrosis. One died because of grade IV mucositis and overlapping infection. Conclusions: The treatment of recurrent NPC is controversial. Fractionated stereotactic radiotherapy is promising. However, the published trials are heterogeneous with respect to the selection criteria and treatment details. Prospective studies with long term follow-up data are warranted.

2-Methylisoborneol(2-MIB)제거를 위한 산화 및 흡착공정의 특성 (The Characteristics of Oxidation and Adsorption Processes for 2-Methylisoborneol(2-MIB) Removing)

  • 최근주;김상구;류동춘;신판세;손인식;오광중
    • 한국환경과학회지
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    • 제11권3호
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    • pp.241-246
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    • 2002
  • One of the Musty and earthy smell compounds in raw water is generally attributed to 2-methylisoborneol (2-MIB). It is well known that activated carbon and oxidants such as $O_3$, Cl $O_2$, are effective ways to control 2-MIB. In isotherm equilibrium experiments, 2-MIB in distilled water was much more adsorbed to the activated carbon(A/C) than raw water containing dissolved organic carbon (DOC). The Freundlich constants(k) of distilled water and raw water were 3.36 and 0.049, and 1/n values were 0.80 and 0.42, respectively. The 2-MIB residual rate were Y = $e^{-0}$.55x/~ $e^{-0}$.54x/ with Ozone( $O_3$) dose by 5 minutes contact time at the 241 and 353 ng/L initial concentrations. The 2-MIB residual rate were Y = $e^{-0}$.32x/~ $e^{-0}$.35x/ with Chlorine dioxide(Cl $O_2$) dose by 15 minutes contact time at the 89 and 249 ng/L initial concentrations. 2-MIB was decreased from 1911 ng/L to 569ng/L by post-ozonation(70%removal efficiency) and removal efficiencies of 2-MIB by the following 4 kinds Granular Activated Carbon(GAC) process such as coal base, coconut base, wood base and zeolite+carbon base were 95.8, 89.5, 88.4, and 93.7% respectively.ely.

Effect of Plant Based Essential Oil on Immune Response of Silkworm, Antheraea assama Westwood (Lepidoptera: Saturniidae)

  • Khanikor, Bulbuli;Bora, Dipsikha
    • International Journal of Industrial Entomology and Biomaterials
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    • 제25권2호
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    • pp.139-146
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    • 2012
  • Botanicals have been regarded as sustainable solution of pest control because of their nominal effect on nontarget pest, biodegradability and other environment friendly properties. However, study on impact of botanicals against beneficial insects is less. In this investigation effort has been made to study the effect of essential oils of Ocimum sanctum, Ocimum gratissimum and Ageratum conyzoides against non-mulberry silkworm Antheraea assama in terms of percent mortality, total haemocyte count (THC) and phenol oxidase (PO) enzyme activity. After application of essential oil of the plants by contact residual film technique, age dependent decrease of percent mortality was recorded. Topical treatment of oil at higher dosages ($1{\mu}lg^{-1}$ and $0.5{\mu}lg^{-1}$) caused 100% mortality of late instar larvae at 24 hour but the lowest dose ($0.25{\mu}lg^{-1}$) did not cause any mortality till 48 hour of treatment. Initial increase of total haemocyte count (THC) was recorded at early hours of treatment (0.25 hour) at all dosages (1, 0.5, $0.25{\mu}lg^{-1}$) after topical treatment. A dose dependent increase was observed in phenol oxidase enzyme activity and this might indicate ability of the essential oils to cause induction of immune response in Antheraea assama larvae.

Hypofractionated three-dimensional conformal radiotherapy for medically inoperable early stage non-small-cell lung cancer

  • Lee, Joo Ho;Wu, Hong-Gyun;Kim, Hak Jae;Park, Charn Il;Lee, Se-Hoon;Kim, Dong-Wan;Heo, Dae Seog
    • Radiation Oncology Journal
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    • 제31권1호
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    • pp.18-24
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    • 2013
  • Purpose: The purpose of this study was to assess the clinical outcomes of hypofractionated radiotherapy (HFRT) with three-dimensional conformal technique for medically inoperable patients with early stage non-small-cell lung cancer (NSCLC) and to evaluate prognostic factors. Materials and Methods: We performed a retrospective review of 26 patients who underwent HFRT for early stage NSCLC between September 2005 and August 2011. Only clinical stage T1-3N0 was included. The median RT dose was 70 Gy (range, 60 to 72 Gy) and the median biologically equivalent dose (BED) was 94.5 Gy (range, 78.0 to 100.8 Gy). In 84.6% of patients, 4 Gy per fraction was used. Neoadjuvant chemotherapy with paclitaxel and cisplatin was given to 2 of 26 patients. Results: The median follow-up time for surviving patients was 21 months (range, 13 to 49 months). The overall response rate was 53.9%, and the initial local control rate was 100%. The median survival duration was 27.8 months. Rates of 2-year overall survival, progression-free survival (PFS), local control (LC), and locoregional-free survival (LRFS) were 54.3%, 61.1%, 74.6%, and 61.9%, respectively. Multivariate analysis showed that BED (>90 vs. ${\leq}90$ Gy) was an independent prognostic factor influencing PFS, LC, and LRFS. Severe toxicities over grade 3 were not observed. Conclusion: Radical HFRT can yield satisfactory disease control with acceptable rates of toxicities in medically inoperable patients with early stage NSCLC. HFRT is a viable alternative for clinics and patients ineligible for stereotactic ablative radiotherapy. BED over 90 Gy and 4 Gy per fraction might be appropriate for HFRT.

잠란(蠶卵)의 초기발육과정(初期發育過程)에 따르는 RNase활성(活性) 및 핵산량(核酸量)의 변동(變動) 및 그 X선조사(線照射)에 의한 영향(影響)에 관(關)한 연구(硏究) (Variation of RNase activities and nucleic acid content of non-irradiated and irradiated eggs of Bombyx mori during early development of embryo)

  • 이기영;전형원
    • Applied Biological Chemistry
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    • 제15권2호
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    • pp.163-168
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    • 1972
  • Previously identified female pupae were X-irradiated with a dose of 1000r one day prior to moth transformation. Female mothes from irradiated and non-irradiated pupae were copulated with normal male ones and allowed to lay eggs. Fertilized eggs were collected at 6 intervals such as 5, 15, 45, 90 minutes, 12 and 40 hours after laying, and deep-freezed immediately after each collection until measurements. RNase activity and nucleic acid content were determined with each sample and following results were obtained. 1) It was proved to exist two RNases in silk worm eggs as in mammalian tissues, one active maximally at pH 5.8 and the other at pH 8.0, and the acid RNase activity was much higher than that of alkaline RNase. 2) The activity of acid and alkaline RNases increased remarkably during early development of the embryo of silk worm eggs, reaching the maximum activity at 45 minutes from laying time in non-irradiated group. There was no appreciable difference in two RNase activities for 45 minutes after laying in both control and irradiated groups, but the activity of acid and alkaline RNases in latter group was three times as much as that in former group, at 90 minutes from laying time and it was also found the acid RNase activity was 1.8 times higher than alkaline one in irradiated group. 3) The RNA-P content of control group increased considerably for initial 45 minutes, followed by a decline 45 minutes later with sight but steady increase thereafter. The RNA-P content of irradiated group, however, increased at initial 5 minutes, followed by a marked fall 90 minutes after laying, with no change thereafter. The DNA-P of control group showed a sharp increase for initial 45 minutes, followed by a decline 45 minutes later with no appreciable change thereafter, whereas that of irradiated group showed an increase at initial 15 minutes, followed by a sharp decline for following 45 minutes with a gradual increase thereafter. It was thus proved that the synthesis of nucleic acid in silk worm eggs was much suppressed by X-irradiation during early development of embryo. 4) The RNase activity varied in parallel with the RNA-P content in control group, but the RNA-P content in irradiated group was shown to be minimum value in concidence with the maximum activity of both RNases.

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근치적 방사선치료 후 재발한 자궁경부암의 재 방사선치료 (Reirradiation in Rcurrent Cervical Cancer Following Definite Radiation Therapy)

  • 김진희;최태진;김옥배
    • Radiation Oncology Journal
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    • 제19권3호
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    • pp.230-236
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    • 2001
  • 목적 : 저자들은 근치적 방사선치료를 시행받고 골반 내에 재발하여 재 방사선치료를 받은 자궁경부암 환자를 대상으로 생존률, 부작용 등 결과를 분석하고자 하였다. 대상 및 방법 : 1987년 11월부터 1998년 3월까지 계명대학교 동산의료원 치료방사선과에서 근치적 방사선치료를 받고 추적 관찰 중 골반내에 재발하여 재 방사선치료를 받은 환자 18명을 대상으로 하였다. 처음 진단당시 병기로는 Ia 1명, Ib 5명, IIa 5명, IIb 3명, IIIb 2명, IVa 2명으로 평균연령은 57세($37\~79$세)이었다. 재발기간은 6개월에서 122개월로 평균 58개월이었다. 재발부위는 7명에서 자궁경부, 10명에서 질부, 1명에서 골반내 림프절에 재발하였다. 12명은 외부방사선치료와 강내 방사선치료를, 4명은 외부방사선치료와 자입방사선치료를, 2명은 외부방사선치료단독를 시행하였다. 재 방사선치료의 외부방사선량은 $2,100\~5,400\;cGy$이었고 방사선총량은 $3,780\~8,550\;cGy$이었다. 재발 후 추적기간은 8개월에서 80개월로 평균 25개월이었다. 결과 : 재 방사선치료 직후 전체 18명 중 14명$(78\%)$에서 국소 제어가 되었으며 재 방사선치료를 시행한 후 2년 무병생존률은 $53.6\%$이었다. 재발부위에 따라 2년 무병생존률이 질에 재발한 환자 10명에서는 $71.4\%$, 자궁에 재발한 환자 7명에서는 $28.5\%$ (p=0.03)를 나타내어 통계적으로 유의한 차이를 보였다. 재 방사선총량에 따라 2년 무병생존률이 통계적으로 유의하게 차이를 보였다$(>6,000\;cGy\;71.8\%,\;{\leq}6,000\;cGy\;25\%\;p=0.007)$. 재 방사선치료 후 20개월 이상 추적 관찰된 환자 10명중 7명에서 무병생존 중이다(7/18, $39\%$). 외부방사선치료와 강내방사선치료를 시행한 환자에서 가장 좋은 생존률을 보였다. 재 방사선치료 후 실패양상은 국소 재발이 국소 제어 안된 4명을 포함한 7명 $(39\%)$에서 자궁 및 질에 재발하였고 2명에서 원격 전이되어 사망하였다. 부작용으로는 장출혈이 3명에서 있었으며 수술을 요하는 장폐쇄가 2명, 방광손상에 의한 혈뇨가 1명, 2도 방광염이 2명, 연부 부종이 2명, 질부조직괴사가 1명에서 있었으나 자연 치유되었다. 재 방사선치료총량이나 재발기간에 따른 부작용의 차이는 없었다. 결론 : 근치적 방사선치료 후 재발한 경우, 재 방사선치료는 도움이 될 것으로 사료되나 심각한 부작용을 줄이는 노력이 더 요구된다.

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물 재이용을 위한 하수처리장 방류수 색도의 자외선처리에 미치는 과산화수소의 영향 (Effect of Hydrogen Peroxide on UV Treatment of Color in Secondary Effluent for Reclamation)

  • 박기영;맹승규;김기팔;이석헌;권지향;안규홍
    • 상하수도학회지
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    • 제18권3호
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    • pp.377-384
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    • 2004
  • In the present study, a feasibility of an advanced oxidation process using UV/Hydrogen peroxide($H_2O_2$) system equipped with a medium pressure lamp for secondary effluent reclamation was investigated. Initial concentration of $H_2O_2$ and pH were changed to determine the optimum operation condition for the system. The removal efficiency of color was than 80% with 14.3mg/L of initial $H_2O_2$ and 5 minute of contact time in the UV/$H_2O_2$ system. The color removal was analyzed using first-order reaction equation. The dependence of rate constant (k) on initial $H_2O_2$ represented the rational relationship with maximum value. Residual $H_2O_2$ caused increase of effluent COD, since analyzing agent, dichromate, reacted with $H_2O_2$ in the sample. Therefore, excess initial concentration of $H_2O_2$ would significantly affect effluent COD measurement. At pH variation experiment, both residual $H_2O_2$ and color showed peak in the neutral pH range with the same pattern. Effect of $H_2O_2$ dose also enhanced color removal but raised residual $H_2O_2$ problem in the continuous operation UV system. In conclusion, these results indicated that medium pressure UV/$H_2O_2$ system could be used to control color in the secondary effluent for reclamation and reuse.

New Coating Method for Sustained Drug Release: Surface Modification of ePTFE Grafts by inner coating PLGA

  • Kim, Hyeseon;Park, Seohyeon;Kim, Dae Joong;Park, Jong-Sang
    • Bulletin of the Korean Chemical Society
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    • 제35권5호
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    • pp.1333-1336
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    • 2014
  • Expanded polytetrafluoroethylene (ePTFE) grafts have been used as vascular access for many patients suffering from end stage renal disease. However, the vascular graft can cause significant clinical problems such as stenosis or thrombosis. For this reason, many studies have been performed to make drug eluting graft, but initial burst is major problem in almost drug eluting systems. Therefore we used biodegradable polymer to reduce initial burst and make sustained drug delivery. The ePTFE grafts were dipped into a paclitaxel-dissolved solution and then PLGA-dissolved solution was passed through the lumen of ePTFE. We analyzed whether the dose of paclitaxel is enough and the loading amount of PLGA on ePTFE graft increases according to the coating solution's concentration. Scanning electron microscope (SEM) images of various concentration of PLGA showed that the porous surface of graft was more packed with PLGA by tetrahydrofuran solution dissolved PLGA. In addition, in vitro release profiles of Ptx-PLGA graft demonstrated that early burst was gradually decreased as increasing the concentration of PLGA. These results suggest that PLGA coating of Ptx loaded graft can retard drug release, it is useful tool to control drug release of medical devices.

보상여과판을 이용한 비인강암의 전방위 강도변조 방사선치료계획 (Dose Planning of Forward Intensity Modulated Radiation Therapy for Nasopharyngeal Cancer using Compensating Filters)

  • 추성실;이상욱;서창옥;김귀언
    • Radiation Oncology Journal
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    • 제19권1호
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    • pp.53-65
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    • 2001
  • 목적 : 비인강암 환자의 국소제어율을 향상시키기 위한 목적으로 보상 여과판을 이용한 전방위 강도변조 방사선치료방법(intensity modulated radiation therapy : IMRT)을 계획하고 기존 3차원 입체조형치료방법과 비교하여 최적의 방사선치료방법을 모색하고자 한다. 대상 및 방법 : 3-차원 입체조형치료계획으로 치료받았던 비강암환자(T4N0M0) 1예를 선택하여 치료면의 굴곡과 뼈, 공동 등 불균질 조직으로 인하여 발생되는 표적체적의 선량분포를 균일하게 만들고 주변 정상장기의 손상을 최소화하기 위한 일차 입사선량의 강도 조절을 보상여과판으로 시행 하였다. 환자는 열변성 plastic mask로 고정시킨 후 치료조준용 CT Scan (PQ5000)을 이용하여 3 mm 간격으로 scan 하고 가상조준장치(virtual simulator)와 3차원 방사선치료계획 컴퓨터$(ADAC-Pinnacle^3)$를 이용하여 보상여과판을 제작하였다. 각 조사면을 세분한 소조사선(beamlet)의 강도 가중치(weighting)를 계산하고 가중치에 따른 선량 감약을 보상여과판의 두께로 환산하여 판별이 쉽도록 도표화하였다. 방사선 치료성과의 기준은 정량적으로 평가할 수 있는 선량체적표(dose volume histogram : DVH)와 종양억제확율(tumor control probability : TCP)및 정상조직 손상확율(normal tissue complication probability : NTCP)의 수학적 관계식을 이용하여 치료효과를 평가하였다. 결과 : 전방위 IMRT에서 계획용표적체적(planning target volume: PTV)내의 최소선량과 최대선량의 차이가 입체조형치료계획보다 약간 증가하였으며 평균선량은 강도조절치료계획에서 약 $10\%$, 더 높았고 전체 방사선량의 $95\%$가 포함되는 체적(V95)은 비교적 양쪽 설계방법에서 비슷한 양상을 보이고 있었다. 주위 건강장기들의 DVH에서 방사선에 민감한 장기인 시신경, 측두엽, 이하선, 뇌간, 척수, 측두하악골관절 등은 강도조절치료계획에서 많이 보호되었다. PTV의 종양제어확율은 입체조형치료계획과 강도변조치료계획에서 모두 비교적 균일하였으며 계획선량이 50 Gy에서 80 Gy로 증가함에 따라 TCP가 0.45에서 0.56으로 완만하게 증가하였다. 척수, 측두하악골 관절, 뇌간, 측두엽, 이하선, 시신경교차, 시신경 등 정상장기의 손상확율은 입체조형치료계획보다 강도조절치료계획에서 월등히 감소되었으며 특히 뇌간(brain stem)의 NTCP는 입체조형치료계획에서 보다 강도조절치료계획에서 훨씬 적은 값(0.3에서 0.15)으로 감소되었다. 계획선량의 증가에 따른 TCP와 NTCP를 입체조형치료계획과 강도조절치료계획에서 TCP는 공히 완만한 증가를 보였으나 NTCP값은 선량증가에 비례적으로 증가하였고 입체조형치료계획이 강도조절치료계획보다 월등히 증가하였다. 결론 : 보상여과판을 이용한 전방위 강도변조 방사선치료에서 PTV내의 선량 균일도의 개선은 없었지만 뇌간, 척수강 등 정상장기의 피폭을 줄일 수 있었다. 특히 인체표면의 굴곡이 심하거나 뼈, 동공 등으로 종양에 도달하는 방사선량분포가 균일하지 않을 경우 매우 유리한 치료방법이였다. 방사선치료성적을 평가함에 있어 DVH와 TCP, NTCP 등 수학적 척도를 이용함으로서 치료성과의 예측, 종양선량의 증가(dose escalation), 방사선수술의 지표 및 방사선치료의 질적 상황을 정량적 수치로 평가할 수 있어 방사선치료성과 향상에 기여할 수 있다고 생각한다.

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