• Title/Summary/Keyword: total dose

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QUANTITATIVE DATA TO SHOW EFFECTS OF GEOMETRIC ERRORS AND DOSE GRADIENTS ON DOSE DIFFERENCE FOR IMRT DOSE QUALITY ASSURANCE MEASUREMENTS

  • Park, So-Yeon;Park, Jong-Min;Ye, Sung-Joon
    • Journal of Radiation Protection and Research
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    • v.36 no.4
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    • pp.183-189
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    • 2011
  • To quantitatively evaluate how setup errors in conjunction with dose gradients contribute to the error in IMRT dose quality assurance (DQA) measurements. The control group consisted of 5 DQA plans of which all individual field dose differences were less than ${\pm}5%$. On the contrary, the examination group was composed of 16 DQA plans where any individual field dose difference was larger than ${\pm}10%$ even though their total dose differences were less than ${\pm}5%$. The difference in 3D dose gradients between the two groups was estimated in a cube of $6{\times}6{\times}6\;mm^3$ centered at the verification point. Under the assumption that setup errors existed during the DQA measurements of the examination group, a three dimensional offset point inside the cube was sought out, where the individual field dose difference was minimized. The average dose gradients of the control group along the x, y, and z axes were 0.21, 0.20, and 0.15 $cGy{\cdot}mm^{-1}$, respectively, while those of the examination group were 0.64, 0.48, and 0.28 $cGy{\cdot}mm^{-1}$, respectively. All 16 plans of the examination group had their own 3D offset points in the cube. The individual field dose differences recalculated at the offset points were mostly diminished and thus the average values of total and individual field dose differences were reduced from 3.1% to 2.2% and 15.4% to 2.2%, respectively. The offset distribution turned out to be random in the 3D coordinate. This study provided the quantitative data that support the large individual field dose difference mainly stems from possible geometric errors (e.g., random setup errors) under the influence of steep dose gradients of IMRT field.

A Study on Noise Exposure Dose and Blood Pressure in an Automobile (모 자동차 공장의 소음폭로와 혈압에 관한 연구)

  • 김성천
    • Journal of Environmental Health Sciences
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    • v.17 no.2
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    • pp.48-53
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    • 1991
  • This study was carried out to investigate age, noise intensity, work period, hearing loss at frequencies, hypertension and to examine correlation of the total quantity of noise exposure(Dose) and blood pressure (Response) in the auto industry during May 1987-December 1987. To perform this study 65 workers were tested. Results of this study were as follows: 1. In frequency analysis, the CS-dip phenomenon occurred around 4000 Hz. 2. Between under of ten years group and over of ten years group, average hearing loss value was statitically significant (P < 0.05). 3. The prevalence of hypertension of 65 workers was 7.84% . 4. At 90dB(A) over and 10 years under and workers in the 20's group, the total quantity of noise exposure (Dose) and systolic blood pressure (Response) were statistically significant (P < 0.05). 5. At under 10 years of work period group, the total quantity of noise exposure(Dose) and diastolic blood pressure (Response) were statistically significant(r =0.234, P < 0.1).

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A Study on the storage of Ginseng Powder by r-Irradiation (방사선조사에 의한 인삼분말의 저장성에 관한 연구)

  • 민옥녀
    • Journal of Environmental Health Sciences
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    • v.8 no.1
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    • pp.45-53
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    • 1982
  • To determine the effect of r-irradiation on the microorganisms destruction and the changes of general constituents of Ginseng Powder, three samples were analyzed at 1st and 3rd month after r-irradiation. The results were as follows: 1. Total bacterial counts were decreased during storage as the irradiation dose increased. It seems that about 300 Krad was satisfactory to the regulation of ginseng powder. ($5.0 \times 10^4 /g$) 2. Coliform group was also decreased during storage as the irradiation dose increased. Coliform group was not detected at the irradiation dose higher than 500 Krad. 3. Total bacterial counts and coilform group were in proportion to the content of moisture in ginseng powder. 4. The contents of moisture, ash, crude protein, crude lipid and total sugar in ginseng powder during storage had nearly no changes. 5. The content of reducing sugar in ginseng powder during storage had the increasing tendencies as the irradiation dose increased. 6. The content of amino-nitrogen in ginseng powder during storage had the decreasing tendencies as the irradiation does increased.

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Diuretic action of hoelen in the dog (복령의 이뇨작용)

  • ;;Lee, Dohn Ill;Moon, Yung Hee
    • YAKHAK HOEJI
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    • v.18 no.1
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    • pp.39-48
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    • 1974
  • Intravenously administered total water extract of Hoelen, (Pachymae fungus) in a dose of 10mg/kg and its methanol lextract, in a smaller dose than total water extract, produced significantly increase on urinary volume, sodium nad potassium excretion, and osmolar nad free water clearances. Increasing the doses produced more pronounced renal responses. Glomerular filtration rate and renal plasma flow changed littl with both extract. On the contrary, water extract from residue obtained on extraction with organic solvents exhibited no significant changes on the parameters of the renal function. In experiments, in which the total water extract was infused directly into a renal artery and urines from both ureters were collected separetely, a small dose of 0.3mg/kg/min showed no diuresis, but a large dose of 1.0mg/kg/min elicited diuretic action even on the contralateral kindneys. It is, therfore, concluded that Hoelen induces diuresis, mainly by inhibiting reabsorption of electrolytes in the renal tubules, and that the renotropic action may be mediated by some endogenous humoral substances.

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Total Body Irradiation of Childhood Leukemia dose Evaluation due to Changes in the Thickness of the Tissue Compensators (소아백혈병의 전신방사선조사 시 조직보상체의 두께변화에 따른 선량평가)

  • Lee, Dong-Yeon;Kim, Chang-Soo;Kim, Dong-Hyun;Kim, Jung-Hoon
    • The Journal of the Korea Contents Association
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    • v.14 no.4
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    • pp.249-255
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    • 2014
  • Total body irradiation use one of the pre-treatment as hematopoietic stem cell transplantation in the treatment of leukemia. According to the study of Korean network for organ sharing 2013 report, continue to increase the number of hematopoietic stem cell transplantation. however, the current dose evaluation fall short before treatment. So purpose of this study is Surface dose and deep organ dose evaluation and then find the most ideal conditions when change of the thickness on tissue compensator in TBI. Result, surface dose in 4 MV, SSD 280 cm, compensators thickness 0.5 cm, was measured the highest dose 5.84 mGy/min. And the ideal dose showed when compensator thickness less than 1 cm.

Recent Trend of Occupational Exposure to Ionizing Radiation in Korea, 2015-2019

  • Lim, Young Khi
    • Journal of Radiation Protection and Research
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    • v.46 no.4
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    • pp.213-217
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    • 2021
  • Background: Radiation exposure can occur as a result of occupational activities utilizing sources of radiation. The average level of occupational exposure is generally similar to the global average, but some workers receive more than this. In this study, the occupational exposure data for workers in Korea to check the recent trend of radiation exposure. Materials and Methods: The data collection and analysis are carried out by two separate periods based on the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) survey. One is the year 2003 to 2014 for a recent survey, and the other is 2015 to 2019. All available data were collected by annual reports from radiation dose registry organizations. Results and Discussion: The annual dose over the record level to the total workers did not change much compared with the total increasing number of workers in this period. The dose to the nuclear fuel cycle field has a tendency to decrease. It resulted from the efforts of radiation dose reduction with high technology introduced to this area. Also, it is important result that the radiation dose to the workers in radiography is remarkably reduced. Conclusion: The number of radiation workers and average doses were analyzed for occupational categories in Korea. It still needs cooperative efforts between the dose registry organizations for the efficient dose management of Korean radiation workers.

Evaluation of Clinical Risk according to Multi-Leaf Collimator Positioning Error in Spinal Radiosurgery (척추 방사선수술 시 다엽콜리메이터 위치 오차의 임상적 위험성 평가)

  • Dong‑Jin Kang;Geon Oh;Young‑Joo Shin;Jin-Kyu Kang;Jae-Yong Jung;Boram Lee
    • Journal of radiological science and technology
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    • v.46 no.6
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    • pp.527-533
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    • 2023
  • The purpose of this study is to evaluate the clinical risk of spinal radiosurgery by calculating the dose difference due to dose calculation algorithm and multi-leaf collimator positioning error. The images acquired by the CT simulator were recalculated by correcting the multi-leaf collimator position in the dose verification program created using MATLAB and applying stoichiometric calibration and Monte Carlo algorithm. With multi-leaf collimator positioning error, the clinical target volume (CTV) showed a dose difference of up to 13% in the dose delivered to the 95% volume, while the gross tumor volume (GTV) showed a dose difference of 9%. The average dose delivered to the total volume showed dose variation from -8.9% to 9% and -10.1% to 10.2% for GTV and CTV, respectively. The maximum dose delivered to the total volume of the spinal cord showed a dose difference from -14.2% to 19.6%, and the dose delivered to the 0.35 ㎤ volume showed a dose difference from -15.5% to 19.4%. In future research, automating the linkage between treatment planning systems and dose verification programs would be useful for spinal radiosurgery.

Effect of Ganoderma lucidum Extract on Experimentally Induced Hepatic Damage and Hyperlipemic Rats. (영지(靈芝)엑기스가 백서(白鼠)의 실험적(實驗的) 간장중독(肝臟中毒) 및 고지혈증(高脂血症)에 미치는 영향(影響))

  • Lee, Moon-Joo;Chung, Myung-Hyun
    • Korean Journal of Pharmacognosy
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    • v.18 no.4
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    • pp.254-264
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    • 1987
  • This study was attempted to investigate the effect of Ganoderma lucidum (Young-Jii) extract on the activities of GPT GOT Al. P LDH and the level of total bilirubin and total cholesterol in serum of $CCl_4$-intoxicated rats, and on the level of total lipids triglyceride phospholipids and total cholesterol in the serum of experimentally induced hyperlipemic rats, and on the effect of body and liver weight in rats. The results were shown as follows; In $CCl_4$-intoxicated rats, the extract showed a significant decrease in the activities of GPT and Al.P, a slight decrease in the activity of GOT and LDH; The level of total bilirubin was slightly affected, but significantly decreased at a dose as high as 500 mg/kg; the level of total cholesterol was increased dose dependently. In hyperlipemic rats, the extract caused a significant decrease in the level of total lipids and triglyceride and the rate of decrease was more pronounced with repeated treatments for 10 days; the level of phospholipids and total cholesterol were slightly decreased with repeated treatment of the extract at a dose of 300 mg/kg for 10 days; A significant body weight gain was shown with the treatment of the extract.

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Changes of serum immunoglobulin in the subacute oral administration of bisphenol A

  • Byun, Jung-A;Pyo, Myoung-Yun
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.296.1-296.1
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    • 2002
  • Bisphenol A(BPA). a monomer used in the manufacturing epoxy resins and polycarbonates. has been reported to induce estrogenic activity, it has been considered as an environmental endocrine disruptor. But the immunomodulatory effects of BPA exposure have not been systemically evaluated. We investigated whether BPA effects on the ability of immunoglobulin(lg) production of mice. To initiate investigation of BPA-induced alterations of the immune system. BPA at dose of 100. 500,1000 mg/kg b.w./day with or without OVA-antigen for 30 days were orally administered to female ICR mice. Mice were sacrificed and serum was colleted on day 2 following administration of BPA for 30days. Total lgG1. total lgG2a. total lgE. OVA-specific lgG1. OVA-specific lgG2a. and OVA-specific lgE in serum were detetmined and compared with those of non-treated mice. In the groups of BPA with OVA antigen, total 1gG1, total lgG2a, total lgE. OVA-specific lgG1 and OVA-specific lgG2a were significantly decreased at dose of 500mg/kg/day. However, in mice treated with BPA alone, total lgG1, and lgG2 were not much altered and total lgE was significantly increased at dose of 1000mg/kg/day. These results demonstrated the BPA modulates the production of immunoglobulin.

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An Analysis on Treatment Schedule of Carbon Ion Therapy to Early Stage Lung Cancer

  • Sakata, Suoh;Miyamoto, Tadaaki;Tujii, Hirohiko
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.174-176
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    • 2002
  • A total of 134 patients with stage 1 of non-small cell lung cancer treated by carbon ion beam of HIMAC NIRS were investigated for control rate and delivered dose. The delivered dose of every patient was converted to biological effective dose (BED) of LQ model using fraction number, dose per fraction and alpha beta ratio which shows the maximum correlation between BED and tumor control. The BED of every patient was classified to establish a BED response curve for control. Assuming fraction numbers, dose response curves were introduced from BED response curve. The total doses to realize several control rates were obtained for the treatment of small fraction number.

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