• Title/Summary/Keyword: Maximum Dose

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The Comparison of Dose Distribution on Radiation Therapy between IMRT and VMAT in Modified Radical Mastectomy Patients (전유방절제술 환자에서 IMRT와 VMAT을 이용한 방사선치료시 선량 분포의 비교)

  • Ko, Hye-Jin;Kim, Young-Jae;Jang, Seong-Joo
    • The Journal of the Korea Contents Association
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    • v.14 no.8
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    • pp.225-232
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    • 2014
  • Underwent on modified radical mastectomy(MRM) and radiation therapy, it affects increasing rates of chronic morbidity, because of including chest wall and internal mammary nodes(IMNs). It causes the high absorbed dose on heart and ipsilateral lung. Thus in this study, we compared dose distributions through utilizing the intensity modulated radiation therapy(IMRT) and the volumetric modulated arc therapy(VMAT). We selected 10 breast cancer patients at random who took MRM and radiation therapy. Treatment plannings were done by using IMRT and VMAT from each patient ranging supraclavicular lymphnodes(SCL) and IMNs. After that we analysed the planning target volume(PTV)'s conformity and absorbed doses on heart and lungs. As a results, PTV conformities were indicated the same patten(p<0.05) in both plans. In case of Lt breast cancer patients, the dose maximum regions of the heart were more lesser in VMAT technique rather than the IMRT(p<0.05). Also, the maximum dose areas of lungs were lesser in VMAT technique rather than the IMRT(p<0.05). Therefore, it would be safe to say that it is more effective way to adapt the VMAT technique than IMRT in such cases like involve IMNs in breast cancer patients.

Impact of High-Dose Statin Pretreatment in Patients with Stable Angina during Off-Pump Coronary Artery Bypass

  • Youn, Young-Nam;Park, Seong-Yong;Hwang, Yoo-Hwa;Joo, Huyn-Chul;Yoo, Kyung-Jong
    • Journal of Chest Surgery
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    • v.44 no.3
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    • pp.208-214
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    • 2011
  • Background: Periprocedural treatment with high-dose statins is known to have cardioprotective and pleiotropic effects, such as anti-thrombotic and anti-inflammatory actions. We aimed to assess the efficacy of high-dose rosuvastatin loading in patients with stable angina undergoing off-pump coronary artery bypass grafting (OPCAB). Materials and Methods: A total of 142 patients with stable angina who were scheduled to undergo surgical myocardial revascularization were randomized to receive either pre-treatment with 60-mg rosuvastatin (rosuvastatin group, n=71) or no pre-treatment (control group, n=71) before OPCAB. The primary endpoint was the 30-day incidence of major adverse cardiac events (MACEs). The secondary endpoint was the change in the degree of myocardial ischemia as evaluated with creatine kinase-myocardial band (CK-MB) and troponin T (TnT). Results: There were no significant intergroup differences in preoperative risk factors or operative strategy. MACEs within 30 days after OPCAB occurred in one patient (1.4%) in the rosuvastatin group and four patients (5.6%) in the control group, respectively (p=0.37). Preoperative CK-MB and TnT were not different between the groups. After OPCAB, the mean maximum CK-MB was significantly higher in the control group (rosuvastatin group $10.7{\pm}9.75$ ng/mL, control group $14.6{\pm}12.9$ ng/mL, p=0.04). Furthermore, the mean levels of maximum TnT were significantly higher in the control group (rosuvastatin group $0.18{\pm}0.16$ ng/mL, control group $0.39{\pm}0.70$ ng/mL, p=0.02). Conclusion: Our findings suggest that high-dose rosuvastatin loading before OPCAB surgery did not result in a significant reduction of 30-day MACEs. However, high-dose rosuvastatin reduced myocardial ischemia after OPCAB.

Mouse Single Oral Dose Toxicity Test of Lactobacillus-fermented Araliae Continentalis Radix Aqueous Extracts (fACR) (독활의 복합 유산균 발효 추출액의 마우스에 대한 단회경구투여 독성시험)

  • Jung, Young-Mi;Ku, Sae-Kwang;Lee, Dong Sub;Kwon, Kisang
    • Journal of Life Science
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    • v.26 no.2
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    • pp.204-211
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    • 2016
  • The objective of this study was to obtain acute (single) oral dose toxicity information on Lactobacillus-fermented Araliae Continentalis Radix aqueous extracts (fACR) in female and male ICR mice, as compared with Araliae Continentalis Radix aqueous extracts (ACR). After administering a single oral dose of fACR, no treatment-related mortalities were observed within 14 days after the end of treatment up to 2,000 mg/kg, the maximum dosage for rodents of both sexes; moreover, no fACR treatment-related changes in the body and organ weights, clinical signs, necropsy, and histopathological findings were detected in this experiment. In addition, no ACR 2,000 mg/kg treatment-related mortalities, clinical signs, body and organ weights, or gross and histopathological findings were observed, as compared with equal genders of vehicle control. The results obtained in this study suggest that fACR is non-toxic in mice and is, therefore, likely to be safe for clinical use. The LD50 and approximate LD in female mice and male mice, respectively, were considered after a single oral dose of fACR over 2,000 mg/kg, the maximum dosage for rodents. In addition, no specific targets or clinical signs were detected in the present study. ACR 2,000 mg/kg-treated mice also did not show any treatment-related mortalities, clinical signs, changes to body and organ weights, or gross and histopathological findings, as compared with equal genders of vehicle control.

Analysis of the cause of dose delivery errors due to changes in abdominal gas volume during MRgART pancreatic cancer (췌장암 MRgART시 복부가스용적 변화에 의한 선량전달오류 원인 분석)

  • Ha, Min Yong;Son, Sang Jun;Kim, Chan Yong;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.32
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    • pp.73-83
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    • 2020
  • Purpose: The purpose of this study is to confirm the matching of the electron density between tissue and gas due to variation of abdominal gas volume in MRgART (Magnetic Resonance-guided Adaptive Radiation Therapy) for pancreatic cancer patients, and to confirm the effect on the dose change and treatment time. Materials and Methods: We compared the PTV and OAR doses of the initial plan and the AGC(Abdominal gas correction) plans to one pancreatic cancer patient who treated with MRgART using the ViewRay MRIdian System (Viewray, USA) at this clinic. In the 4fx AGC plans, Beam ON(%) according to the patient's motion error was checked to confirm the effect of abdominal gas volume on treatment time. Results: Comparing the Initial plan with the average value of AGC plan, the dose difference was -7 to 0.1% in OAR and decreased by 0.16% on average, and in PTV, the dose decreased by 4.5% to 5.5% and decreased by 5.1% on average. In Adaptive treatment, as the abdominal gas volume increased, the Beam ON(%) decreased. Conclusion: Abdominal gas volume variation causes dose change due to inaccurate electron density matching between tissue and gas. In addition, if the abdominal gas volume increases, the Beam ON(%) decreases, and the treatment time may increase due to the motion error of the patient. Therefore, in MRgART, it is necessary to check the electron density matching and minimize the variability of the abdominal gas.

Identification of Limiting Amino Acids and Determination of Requirement of Total Sulfur-containing Amino Acids in a Low Protein Diet in Young Chicks. (어린병아리에서 저단백질사료내 제한아미노산의 규명과 함유황아미노산의 요구량 결정)

  • Chee, Kew-Mahn
    • Korean Journal of Poultry Science
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    • v.11 no.1
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    • pp.1-12
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    • 1984
  • Since a 13% dietary protein level is generally accepted as a standard in evaluating net protein utilization values of protein sources in chicks, limiting amino acids a 13% protein basal diet containing 15% isolated soy-protein as the only source of dietary protein, were identified. Of such amino acids as methionine, lysine, threonine and tryptophan added to the basal diet singly or as a combination, methionine appeared as the only limiting amino acid for optimum growth of the chicks. When the requirement of total sulfur-containing acids (TSAA) was estimated as the point at which the dose-response curve intersected a line representing the plateau for maximum performance, the TSAA requirements for maximum growth and feed intake were 4.73% and 3.73% of dietary protein, respectively. The values, expressed in terms of TSAA intake, required for maximum weight gain, feed intake and gain/feed ratio were 167.1, 136.8 and 159.1 mg/bird/day, respectively.

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Antinociceptive and gastro-protective effect of the ethanolic extract of the flowering top of Anthocephalus Cadamba Roxb

  • Subhan, Nusrat;Hasan, Raquibul;Hossain, Mokarram;Akter, Raushanara;Majumder, Muntasir Mamun;Rahman, Mostafizur;Ahmed, Kamaluddin;Ghani, Abdul;Alam, Ashraful
    • Advances in Traditional Medicine
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    • v.9 no.4
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    • pp.326-334
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    • 2009
  • The effect of alcoholic extract of Anthocephalus (A.) Cadamba Roxb. was evaluated in experimental models of pain and ulcer. Hot tail flick test, hot plate test and acetic acid induced writhing test were employed for evaluating the peripheral as well as central analgesic mechanism exerted by the extracts. Gastroprotective activity was examined by HCl and ethanol induced gastric damage test. Test group received crude extract 500 mg/kg showed maximum time needed for the response against thermal stimuli (6.26 ${\pm}$ 0.439 s) which is comparable to diclofenac sodium (6.56 ${\pm}$ 0.381 s) in hot tail flick method. These experimental results also followed the experimental results of hot plate test where crude extract 500 mg/kg showed maximum time needed for the response against thermal stimuli (4.74 ${\pm}$ 0.234 s) which is comparable to diclofenac sodium (5.58 ${\pm}$ 0.585 s). The crude extract at 500 and 250 mg/kg showed significant reduction in acetic acid induced writhing in mice with a maximum effect of 68.026% reduction at 500 mg/kg dose which is comparable to standard diclofenac sodium (79.93%). In gastroprotective study the extract of A. Cadamba (250 and 500 mg/kg) significantly inhibited ulceration induced by both HCl and ethanol dose dependently. Results of the study suggest that the extract possesses both analgesic and gastroprotective activity on mice.

Effects Of Minocycline And $TGF-{\beta}1$ On Human Gingival Fibroblasts And Periodontal Ligament Cells In Vitro (Minocycline 및 $TGF-{\beta}1$이 배양 인체 치은섬유모세포와 치주인대세포에 미치는 영향)

  • Yoon, Dong-Hwan;You, Hyung-Keun;Shin, Hyung-Shik
    • Journal of Periodontal and Implant Science
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    • v.26 no.1
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    • pp.188-201
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    • 1996
  • One of the initial events required for periodontal regeneration is the attachment, spreading and proliferation of fibroblasts at the healing sites. These have been reported that minocycline stimulates the attachment of gingival fibroblasts and periodontal ligament cells and $TGF-{\beta}1$ enhances the proliferation of periodontal ligament cells. The purpose of this study was to evaluate and confirm the effect of minocycline and $TGF-{\beta}1$ on human gingival fibroblasts and periodontal ligament cells. That gingival fibroblasts and periodontal ligament cells used in this study were obtained from the explants of healthy periodontal ligaments and gingival tissues of extracted 3rd molars or premolar teeth extracted from the patients with orthodontic treatment. The cells were cultured in ${\alpha}-MEM$(minimal essential medium) supplemented with antibiotics and FBS(fetal bovine serum) at $37^{\circ}C$ in a humidified atmosphere of 5% carbon dioxide-95% air. Cells were used between the 5th to 8th passage in this study. The attachment and activity of both cells were evaluated by MTT assay. The results were as follows: 1. Maximum gingival fibroblast attachment was seen at a $50{\mu}g/ml$ dose of minocycline, while maximum periodontal ligament cell attachment was seen at a $100{\mu}g/ml$, and exposure of both cells to minocycline above maximal attachment dose results in a decline from maximum attachment. 2. The activity values of both cells tested minocycline were below to the control activity values at all concentrations. 3. The attachment values of both cells tested $TGF-{\beta}1$ were below or similar to control attachment values. On the above the findings, minocycline stimulated the cell attachment of gingival fibroblasts and periodontal ligament cells and $TGF-{\beta}1$ enhances the cell activity of periodontal ligament cells.

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Evaluation of the formation and occupation of Gosan-ri archaeological site in Jeju Island using OSL dating (OSL 연대측정을 통한 제주 고산리 유적의 형성과 점유시기 결정)

  • Kim, Myung-Jin
    • Analytical Science and Technology
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    • v.29 no.6
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    • pp.269-276
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    • 2016
  • Gosan-ri site is known as the early Neolithic cultural heritage, in which an archaic plainware, called as the Gosan-ri-type pottery, was excavated regarding as the first pottery manufactured in Korea. In this study, OSL dating was carried out to five soil layer samples collected in stratigraphic cross-section for evaluating the formation and occupation of the Gosan-ri site. Paleodose of each soil sample was calculated using the single aliquot regenerative dose (SAR) method with preheat of $220^{\circ}C$ and finally determined using maximum age model, considering its deposition process. The OSL age was determined from the ratio of paleodose to annual dose rate. From the resultant OSL ages and the related 14C dates, it was concluded that the Gosan-ri site was formed after 9,000 BC and a variety of cultural feature including the Gosan-ri-type pottery were occupied ranging from the early Neolithic to the middle of 4,000 BC. Finally, the Gosan-ri site was discarded in the middle of 4,000 BC and has been arrived at present through natural deposits.

Reduction of Patient Dose in Radiation Therapy for the Brain Tumors by Using 2-Dimensional Vertex or Oblique Vertex Beam Technique

  • Kim, Il-Han;Chie, Eui-Kyu;Park, Charn-Il
    • Journal of Radiation Protection and Research
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    • v.28 no.3
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    • pp.225-231
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    • 2003
  • Up-front irradiation technique as 3-dimensional conformation, or intensity modulation has kept large proportion of brain tumors from being complicated with acute radiation reactions in the normal tissue during or shortly after radiotherapy. For years, we've cannot help but counting on 2-D vertex beam technique to reduce acute reactions in the brain tumor patients because we're not equipped with 3-dimensional planning system. We analyzed its advantages and limitations in the clinical application. From 1998 to 2001, vertex or oblique vertex beams were applied to 35 patients with primary brain tumor and 25 among them were eligible for this analysis. Vertex(V) plans were optimized on the reconstructed coronal planes. As the control, we took the bilateral opposed techniques(BL) otherwise being applied. We compared the volumes included in 105% to 50% isodose lines of each plan. We also measured the radiation dose at various extracranial sites with TLD. With vertex techniques, we reduced the irradiated volumes of contralateral hemisphere and prevented middle ear effusion at contralateral side. But the low dose volume increased outside 100%; the ratio of V to BL in irradiated volume included in 100%, 80%, 50% was 0.55+/-0.10, 0.61+/-0.10, and 1.22+/-0.21, respectively. The hot area within 100% isodose line almost disappeared with vertex plan; the ratio of V to BL in irradiated volume included in 103%, 105%, 108% was 0.14+/-0.14, 0.05./-0.17, 0.00, respectively. The dose distribution within 100% isodose line became more homogeneous; the ratio of volume included in 103% and 105% to 100% was 0.62+/-0.14 and 0.26+/-0.16 in BL whereas was 0.16+/-0.16 and 0.02+/-0.04 in V. With the vertex techniques, extracranial dose increased up to $1{\sim}3%$ of maximum dose in the head and neck region except submandibular area where dose ranged 1 to 21%. From this data, vertex beam technique was quite effective in reduction of unnecessary irradiation to the contralateral hemispheres, integral dose, obtaining dose homogeneity in the clinical target. But it was associated with volume increment of low dose area in the brain and irradiation toward the head and neck region otherwise being not irradiated at all. Thus, this 2-D vertex technique can be a useful quasi-conformal method before getting 3-D apparatus.

Feasibility Study for Development of Transit Dosimetry Based Patient Dose Verification System Using the Glass Dosimeter (유리선량계를 이용한 투과선량 기반 환자선량 평가 시스템 개발을 위한 가능성 연구)

  • Jeong, Seonghoon;Yoon, Myonggeun;Kim, Dong Wook;Chung, Weon Kuu;Chung, Mijoo;Choi, Sang Hyoun
    • Progress in Medical Physics
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    • v.26 no.4
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    • pp.241-249
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    • 2015
  • As radiation therapy is one of three major cancer treatment methods, many cancer patients get radiation therapy. To exposure as much radiation to cancer while normal tissues near tumor get little radiation, medical physicists make a radiotherapy plan treatment and perform quality assurance before patient treatment. Despite these efforts, unintended medical accidents can occur by some errors. In order to solve the problem, patient internal dose reconstruction methods by measuring transit dose are suggested. As feasibility study for development of patient dose verification system, inverse square law, percentage depth dose and scatter factor are used to calculate dose in the water-equivalent homogeneous phantom. As a calibration results of ionization chamber and glass dosimeter to transit radiation, signals of glass dosimeter are 0.824 times at 6 MV and 0.736 times at 10 MV compared to dose measured by ionization chamber. Average scatter factor is 1.4 and Mayneord F factor was used to apply percentage depth dose data. When we verified the algorithm using the water-equivalent homogeneous phantom, maximum error was 1.65%.