• Title/Summary/Keyword: high dose rate

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Efficacy of High Dose Radiotherapy in Post-operative Treatment of Glioblastoma Multiform - A Single Institution Report

  • Pashaki, Abdolazim Sedighi;Hamed, Ehsan Akbari;Mohamadian, Kamal;Abassi, Mohammad;Safaei, Afsane Maddah;Torkaman, Tayebe
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.6
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    • pp.2793-2796
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    • 2014
  • Background: Glioblastoma multiform (GBM) is a highly aggressive tumor with median survival of approximately 14 months. Management consists of maximal surgical resection followed by post-operative chemoradiation with concurrent then adjuvant temozolamide. The standard radiotherapy dose is 60Gy in 2-Gy fractions recommended by the radiation therapy oncology group (RTOG). With the vast majority of tumor recurrences occurring within the previous irradiation field and the poor outcome associated with standard therapy, regimens designed to deliver higher radiation doses to improve local control and enhance survival are needed. In this study, we report a single institutional experience in treatment of 68 consecutive patients with GBM, treated with resection, and given post-operative radiotherapy followed by concurrent and/or adjuvant chemotherapy. Results: Of the 80 patients who entered this study, 68 completed the treatment course; 45 (66.2%) males and 23 (33.8%) females with a mean age at diagnosis of $49.0{\pm}12.9$ (21-75) years. At a median follow up of 19 months, 39 (57.3%) patients had evidence of tumor progression and 36 (52.9%) had died. The median over all survival for all patients was 16 months and progression free survival for all patients was 6.02 months. All potential prognostic factors were analyzed to evaluate their effects on overall survival. Age ${\leq}50$ year, concurrent and adjuvant chemotherapy and extent of surgery had significant p values. We found lower progression rate among patients who received higher doses of radiotherapy (>60Gy). Higher radiation doses improved progression free survival (p=0.03). Despite increasing overall survival, this elevation was not significant. Conclusions: This study emphasize that higher radiation doses of (>60Gy) can improve local control and potentially survival, so we strongly advise prospective multi centric studies to evaluate the role of higher doses of radiotherapy on GBM patient outcome.

The Removal of Algae by Pre-oxidation (전산화 공정을 이용한 조류제거)

  • Son, Hee-Jong;Jung, Chul-Woo;Bae, Sang-Dae;Choi, Young-Ik;Kang, Lim-Seok
    • Journal of Environmental Science International
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    • v.18 no.3
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    • pp.289-298
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    • 2009
  • The blue-green algae which caused odor problem in the tap water are difficult to precipitate in sedimentation basin and clogged the filter void rapidly. The studies of this paper were not only oxidation, coagulation and sedimentation processes for effectively removing blue-green algae but yellow clay and polyamine for verification as coagulants aids. The results of this research are summarized as follows: Higher ozone dose(C) and longer contact time(T) were needed for a high degree of removing blue-green algae efficiency. the removal rate of blue-green algae was proportional to the $C\times T$ value. The removal percent of chlorophyll-a by sedimentation and filter without pre-ozonation was about 75% but 1 mg/L pre-ozonation could increase the removal percent of chlorophyll-a to 99% and more pre-ozonation could remove completely. Though the removal efficiency of turbidity could increased by high dose of chlorination, the dissolved organic carbon was increased. More chlorine dose from 4 to 10 mg/L dissolved organic carbon was decreased. Using yellow clay as coagulant aids increased density of floc so the settling velocity of floc become rising but polyamine could not increase settling velocity of floc though it could formated large floc.

Protective Effect of Herbal Mixture Including Lycii Fructus on Hepatotoxicity Induced by Thioacetamide in Mice (구기자 복합물 약침액이 간기능 개선에 미치는 영향)

  • Kim, Yong-Min;Hwang, Dong-Suk;Kwak, Byeong-Mun;Kim, Ee-Hwa
    • Korean Journal of Acupuncture
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    • v.36 no.4
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    • pp.221-229
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    • 2019
  • Objectives : This study investigated the hepatoprotective effect of herbal mixture including Lycii fructus (HML) in thioacetamide (TAA)-induced hepatotoxicity in mice. Methods : To confirm the liver protective effect, induced by TAA for 3 days injection at 100 mg/kg mice, HML were treated for 8 weeks at 300 mg/kg/day, 1000 mg/kg/day. Positive control was treated silymarin 50 mg/kg/day after TAA injection. The changes of mortality rate, clinical signs, organ weight, relative liver, blood chemistry and histopathological findings were analyzed after experiment. Results : Body weight gain was observed in all groups, but TAA treated group at 4th week and all treated groups decreased weight compared to the untreated group. As a result of organ weight measurement, organ weight gain due to hepatic injury was observed statistically significantly in TAA-treated group and TAA+Silymarin treated group, and the herbal mixture-treated group showed a tendency to decrease compared to the TAA treated group. Blood biochemistry showed that total cholesterol and very low density lipoprotein cholesterol decreased statistically in TAA+low-dose and high dose herbal mixture treated group compared to the TAA-treated group. Histopathological examination showed that liver abnormalities were not observed in untreated group, liver fibrosis was observed in liver injury with TAA treated and herbal mixture treated group. And, TAA+high dose herbal mixture group showed relaxation tendency on liver calcification compared to the TAA treated group. Conclusions : According to the above results, HML provided hepatoprotective effects on the hepatic injury by reduction of inflammatory responses.

Preparation and Characterization of Alginate-Chitosan Microsphere for Controlled Delivery of Silver Sulfadiazine (설파디아진은의 방출제어를 위한 알지네이트-키토산 미립구의 제조 및 특성)

  • Cho, Ae-Ri
    • Journal of Pharmaceutical Investigation
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    • v.31 no.2
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    • pp.101-106
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    • 2001
  • Alginate-chitosan (anion-cationic polymeric complex) was prepared to control the release rate of silver sulfadiazine (AgSD). Na-alginate (2%) solution containing AgSD was gelled in $CaCl_2$ solution. The gel beads formed were immediately encapsulated with chitosan (CS). The gel matrix and membrane were then reinforced with chondroitin-6-sulfate (Ch6S). Release rate of AgSD from the gel matrix was investigated by placing alginate beads in the sac of cellulose membrane simmered in HEPES-buffer solution. The concentration of AgSD released was analyzed by UV at 264 nm. Incorporation capacity of AgSD in Ca-alginate gel was more than 90%. Alginate-Ch6S-CS could control the release rate of AgSD. The amount of AgSD release was dependent on the AgSD loading dose. Incorporation of tripolyphosphate (polyanionic crosslinker) onto the alginate-Ch6S-CS bead increased the release rate of AgSD. Collagen-coating had no influence on the AgSD release rate. Alginate-Ch6S-CS beads with a sufficiently high AgSD encapsulation were capable of controlling the release of the drug over 10 days. In summary, alginate-Ch6S-CS beads could be used as a sustained delivery for AgSD and provide local targeting with low silver toxicity and patient discomfort.

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Differentiation of tidal volume & mean airway pressure with different Bag-Valve-Mask compression depth and compression rate (Bag-Valve-Mask의 사용방법에 따른 일회호흡량과 평균기도압의 변화 연구)

  • Jo, Seung-Mook;Jung, Hyung-Keon
    • The Korean Journal of Emergency Medical Services
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    • v.16 no.2
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    • pp.67-74
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    • 2012
  • Purpose : The purpose of this study is to get basal user guidelines of safer bag-valve-mask application on patient with normal pulmonary patho-physiologic condition. Methods : This study was accomplished by pre-qualified 25 EMS junior grade students. Participants were instructed randomly compress bag to one-third, half and total and also with differesnt compression speed. Resultant tidal volumes and mean airway pressures obtained in RespiTrainer were analysed in relation to the each compression depth and rate. Results : Demographic difference does not affect tidal volume with any compression depth and rate change. Increasing compression depth is correlated with tidal volume increasement at any compression rate and also with mean airway pressure. If the compression depth is same, compression rate change did not affect significantly the resultant tidal volume or mean airway pressure. Conclusion : Hand size, Experience, BMI dose not affect tidal volume. Compress the 1600 ml bag half to total amount is safe way to offer sufficient tidal volume without risky high airway pressure delivery to patient airway who with normal lung patho-physiologic condition.

The Effects of High Dose Rate Brachytherapy in Recurrent Obstructive Bronchogenic Cancer after External Irradiation Therapy (외부 방사선 치료 조사후 재발한 기관지내 악성종양에서 고선량율 근접조사치료(High Dose Rate Brachytherapy)의 효과)

  • Cho, Jae-Youn;In, Kwang-Ho;Suh, Jung-Kyung;Kang, Sea-Yong;Shim, Jae-Jeong;Kang, Kyung-Ho;Kim, Kwang-Taak;Kim, Cheol-Yong;Yoo, Sa-Hwa
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.1
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    • pp.68-76
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    • 1998
  • Background: Patients with centrally recurred bronchogenic carcinoma make a complaint of many symptoms like hemoptysis, cough & dyspnea. At these conditions, the goal of treatment is only to relieve their symptoms. High dose rate brachytherapy(HDR-BT) is the palliative treatment modality of centrally located endobronchial tumor regardless of previous external irradiation(XRT) on the same site in symptomatic patients. Methods: We studied the effects of HDR-BT in 26 patients with symptomatic recurrent lung cancer. Patients(male: 24, mean age: 54yrs)were treated with HDR-BT underwent bronchoscopic placement of $^{192}Ir$ HDR after loading unit(Gammamed$^{(T)}$, Germany) to deliver 500cGY intraluminal irradiation at a depth of 1cm every lwk on 3 occasions. Evaluation at base line and 4wks after HDR brachytherapy included chest X-ray, bronchscopy, symptoms (Standadized Scale for dyspnea,cough,hemoptysis), and Karnofsky performance scale. Results: Endobronchial obstruction was improved in 11/26 patients(37%). Atelectasis in chest X-ray was improved in 5/15 patients(33%). Hemoptysis, dyspnea & cough were improved in 5/10 patients (50%), 5/8 patients (62%) & 10/18 patients (56%) respectively. Karnofsky performance status was changed from 76.4 scores in pretreatment to 77.6 scores after treatment. During HDR-BT, massive hemoptysis (2 patients) and pneumothorax(1 patient) were occurred as complications. Conclusion: We concluded that HDR-BT gave additional benefits for the control of symptoms and general performance and endobronchial obstruction & atelectasis. And HDR-BT will be an additional treatment for the recurrent and endobronchial obstructive lung cancer.

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Pregnancy outcomes following the administration of high doses of dexamethasone in early pregnancy

  • Ahmadabad, Hasan Namdar;Jafari, Sabah Kayvan;Firizi, Maryam Nezafat;Abbaspour, Ali Reza;Gharib, Fahime Ghafoori;Ghobadi, Yusef;Gholizadeh, Samira
    • Clinical and Experimental Reproductive Medicine
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    • v.43 no.1
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    • pp.15-25
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    • 2016
  • Objective: In the present study, we aimed to evaluate the effects of high doses of dexamethasone (DEX) in early pregnancy on pregnancy outcomes. Methods: Pregnant BALB/c mice were treated with high-dose DEX in the experimental group or saline in the control group on gestational days (GDs) 0.5 to 4.5. Pregnant mice were sacrificed on GDs 7.5, 13.5, or 18.5 and their peripheral blood, placentas, fetuses, and uterine tissue were collected. Decidual and placenta cell supernatants were examined to evaluate the effect of DEX on the proliferation of mononuclear cells, the quantity of uterine macrophages and uterine natural killer (uNK) cells, and levels of progesterone and $17{\beta}-estradiol$, as determined by an 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay, immunohistochemistry, and enzyme-linked immunosorbent assay, respectively. We also were measured fetal and placental growth parameters on GD 18.5. Results: We found that high doses of DEX were associated with an increased abortion rate, enhancement of the immunosuppressive effect of the decidua, alterations in placental growth parameters, decreased progesterone and $17{\beta}-estradiol$ levels, and a reduced frequency of macrophages and uNK cells. Conclusion: Our data suggest that the high-dose administration of DEX during early pregnancy negatively affected pregnancy outcomes.

Quantitative Analysis of Lovastatin in Human Plasma and urine by Reversed-Phase High-Performance Liquid Chromatography (역상 고속액체크로마토그라프법을 이용한 혈장 및 뇨 중 로바스타틴의 정량)

  • Choi, Hye-Jin;Kim, Myoung-Min;Choi, Kyung-Eob
    • YAKHAK HOEJI
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    • v.42 no.5
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    • pp.473-479
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    • 1998
  • Lovastatin (LOVA), a fungal metabolite isolated from cultures of Aspergillus terreus, is a competitive HMG-CoA reductase inhibitor used for the treatment of primary hyper cholesterolemia, and has also been shown to suppress growth in a variety of non-glioma tumor cell lines. A sensitive reversed-phase high-perfonnance liquid chromatographic method with ultraviolet (UV) absorbance detection has been developed to quantitate LOVA in human plasma and urine samples using liquid-liquid extraction procedure. Baseline separation of LOVA and internal standard, simvastatin was achieved on a Novapak $C_{18}$ analytical column with a mobile phase containing 0.025M $NaH_2PO_4$: CAN (35:65, v/v%), adjusted pH to 4.5. The flow rate was set at 1.5ml/min, and the column effluent was monitored by a UV detection at 238nm. The limit of quantification was determined to be 0.5${\mu}$g/ml while extraction efficiency of LOVA ranged from 73.4-82.9% at LOVA concentrations of 0.5 to 10${\mu}$g/ml. Good linearity with correlation coefficients greater than 0.999 was obtained in the range of LOVA concentrations from 0.5 to 10${\mu}$g/ml. The accuracy and the precision were proven excellent with relative standard deviation (RSD, %) and relative error (RE, %) of less than 4.2 and 4.0, respectively. Intraday precision, evaluated at five LOVA concentrations (0.5, 1, 2, 5, 10${\mu}$g/ml) and expressed as RSD ranged from 0-1.82% while the interday precision at the same concentrations ranged from 0.7-10.5%. The analytical method described was then successfully employed for the determination of LOVA concentrations in plasma samples obtained during a phase II clinical trial using high doses of LOVA (30-40mg/kg/day). This method could be further utilized for the ongoing pharmacolkinetic studies and therapeutic drug monitoring of the high-dose LOVA therapy in adenocarcinoma patients.

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Dose Verification Study of Brachytherapy Plans Using Monte Carlo Methods and CT Images (CT 영상 및 몬테칼로 계산에 기반한 근접 방사선치료계획의 선량분포 평가 방법 연구)

  • Cheong, Kwang-Ho;Lee, Me-Yeon;Kang, Sei-Kwon;Bae, Hoon-Sik;Park, So-Ah;Kim, Kyoung-Joo;Hwang, Tae-Jin;Oh, Do-Hoon
    • Progress in Medical Physics
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    • v.21 no.3
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    • pp.253-260
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    • 2010
  • Most brachytherapy treatment planning systems employ a dosimetry formalism based on the AAPM TG-43 report which does not appropriately consider tissue heterogeneity. In this study we aimed to set up a simple Monte Carlo-based intracavitary high-dose-rate brachytherapy (IC-HDRB) plan verification platform, focusing particularly on the robustness of the direct Monte Carlo dose calculation using material and density information derived from CT images. CT images of slab phantoms and a uterine cervical cancer patient were used for brachytherapy plans based on the Plato (Nucletron, Netherlands) brachytherapy planning system. Monte Carlo simulations were implemented using the parameters from the Plato system and compared with the EBT film dosimetry and conventional dose computations. EGSnrc based DOSXYZnrc code was used for Monte Carlo simulations. Each $^{192}Ir$ source of the afterloader was approximately modeled as a parallel-piped shape inside the converted CT data set whose voxel size was $2{\times}2{\times}2\;mm^3$. Bracytherapy dose calculations based on the TG-43 showed good agreement with the Monte Carlo results in a homogeneous media whose density was close to water, but there were significant errors in high-density materials. For a patient case, A and B point dose differences were less than 3%, while the mean dose discrepancy was as much as 5%. Conventional dose computation methods might underdose the targets by not accounting for the effects of high-density materials. The proposed platform was shown to be feasible and to have good dose calculation accuracy. One should be careful when confirming the plan using a conventional brachytherapy dose computation method, and moreover, an independent dose verification system as developed in this study might be helpful.

Characteristic Evaluation of Medical X-Ray Using High-Voltage Generator with Inverter System (인버터방식의 고전압 발생장치를 이용한 의료용 X선 기기의 특성평가)

  • Kim, Young-Pyo;Cheon, Min-Woo;Park, Yong-Pil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.1
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    • pp.36-41
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    • 2011
  • Medical X-ray has been brought many changes according to the rapid development of high technology. Especially, for high-voltage generator which is the most important in X-ray generation the traditional way is to use high-voltage electric transformers primarily. However, since it is large and heavy and the ripple rate of DC high-voltage applied to X-ray tube is too big, it has a disadvantage of low X-ray production efficiency. To solve these problems, the studies about high-voltage power supply are now proceeding. At present, the high-voltage generator that generates high-voltage by making high frequency using inverter control circuit consisting of semiconductor device is mainly used. High-voltage generator using inverter has advantages in the diagnosis using X-ray including high performance with short-term use, miniaturization of power supply and ripple reduction. In this study, the X-ray high-voltage device with inverter type using pulse width modulation scheme to the control of tube voltage and tube current was designed and produced. For performance evaluation of produced device, the control signal analysis, irradiation dose change and beam quality depending on the load variation of tube voltage and tube current were evaluated.