• Title/Summary/Keyword: Internal Dose Assessment

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A Study on Usefulness of Clinical Application of Metal Artifact Reduction Algorithm in Radiotherapy (방사선치료 시 Metal artifact reduction Algorithm의 임상적용 유용성평가)

  • Park, Ja Ram;Kim, Min Su;Kim, Jeong Mi;Chung, Hyeon Suk;Lee, Chung Hwan;Back, Geum Mun
    • The Journal of Korean Society for Radiation Therapy
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    • v.29 no.2
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    • pp.9-17
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    • 2017
  • Purpose: The tissue description and electron density indicated by the Computed Tomography(CT) number (also known as Hounsfield Unit) in radiotherapy are important in ensuring the accuracy of CT-based computerized radiotherapy planning. The internal metal implants, however, not only reduce the accuracy of CT number but also introduce uncertainty into tissue description, leading to development of many clinical algorithms for reducing metal artifacts. The purpose of this study was, therefore, to investigate the accuracy and the clinical applicability by analyzing date from SMART MAR (GE) used in our institution. Methode: and material: For assessment of images, the original images were obtained after forming ROIs with identical volumes by using CIRS ED phantom and inserting rods of six tissues and then non-SMART MAR and SMART MAR images were obtained and compared in terms of CT number and SD value. For determination of the difference in dose by the changes in CT number due to metal artifacts, the original images were obtained by forming PTV at two sites of CIRS ED phantom CT images with Computerized Treatment Planning (CTP system), the identical treatment plans were established for non-SMART MAR and SMART MAR images by obtaining unilateral and bilateral titanium insertion images, and mean doses, Homogeneity Index(HI), and Conformity Index(CI) for both PTVs were compared. The absorbed doses at both sites were measured by calculating the dose conversion constant (cCy/nC) from ylinder acrylic phantom, 0.125cc ionchamber, and electrometer and obtaining non-SMART MAR and SMART MAR images from images resulting from insertions of unilateral and bilateral titanium rods, and compared with point doses from CTP. Result: The results of image assessment showed that the CT number of SMART MAR images compared to those of non-SMART MAR images were more close to those of original images, and the SD decreased more in SMART compared to non-SMART ones. The results of dose determinations showed that the mean doses, HI and CI of non-SMART MAR images compared to those of SMART MAR images were more close to those of original images, however the differences did not reach statistical significance. The results of absorbed dose measurement showed that the difference between actual absorbed dose and point dose on CTP in absorbed dose were 2.69 and 3.63 % in non-SMRT MAR images, however decreased to 0.56 and 0.68 %, respectively in SMART MAR images. Conclusion: The application of SMART MAR in CT images from patients with metal implants improved quality of images, being demonstrated by improvement in accuracy of CT number and decrease in SD, therefore it is considered that this method is useful in dose calculation and forming contour between tumor and normal tissues.

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Gross Beta Screening and Monitoring Procedure using Urine Bioassay for Radiation Workers of Radioisotope Production Facilities (뇨시료 전베타 분석법을 이용한 동위원소 생산시설 종사자 내부오염 스크리닝 및 감시절차 개발)

  • Yoon, Seokwon;Kim, Mee-Ryeong;Park, Seyoung;Pak, Min-Jeong;Yoo, Jaeryong;Jang, Han-Ki;Ha, Wi-Ho
    • Journal of Radiation Protection and Research
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    • v.38 no.2
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    • pp.52-59
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    • 2013
  • The internal contamination screening method using gross beta measurement was performed for radioisotope workers. 24 h and spot urine samples from workers of medical isotope production facilities were collected and measured. Most of the results were similar with the background level of gross beta activity except for a specific worker. Gross beta activity was slightly increased in several hours after finishing work. And the environmental factor of production facilities causing internal contamination were estimated based on screening results. The additional detailed internal dose assessment must be followed after the screening for protection of workers. Moreover, a procedure was established to apply a simple internal contamination assessment for radiation workers.

Adverse Effects of Ma-huang according to Dose : A Randomized Double-Blind Placebo-Controlled Pilot Study (마황용량에 따른 이상반응에 관한 예비연구: 무작위배정이중맹검시험)

  • Hsing, Li-Chang;Lee, Tae-Ho;Son, Dong-Hyug;Yeo, Jin-Ju;Yang, Chang-Sop;Seo, Eui-Seok;Jang, In-Soo
    • The Journal of Internal Korean Medicine
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    • v.27 no.1
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    • pp.188-196
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    • 2006
  • Background: Ma-huang (Ephedra sinica) has been widely used to treat respiratory disease in oriental medicine for over a hundred years. Ma-huang preparations contain approximately 1.25% ephedrine alkaloids. Recently, the ephedra alkaloids have received much press lately due to adverse effects in those using whole extracts as 'dietary supplements' for weight loss or athletic performance enhancement, and these reports are troubling given the increasing use of Ma-huang by the general public. The purpose of this report is to determine the proper dosage to minimize adverse effects and maximize the potential curative value. Objectives : The object of this study was to find an effective yet low risk dosage of Ma-huang. Methods : The study was designed as a double-blind randomized placebo-controlled trial. The subjects of this study were 26 adults between 20 to 40 of age who agreed to participate in this study. They were allocated through randomization into three groups. Each group took three opaque capsules three times a day. A group (N=9) took one Ma-huang capsule and two placebo capsules, B group (N=8) took two Ma-huang capsules and one placebo capsule, C group (N=9) took three Ma-huang capsules. The total trial periods was two days. To compare the adverse effects of Ma-huang according to dosage, blood pressure and pulse were checked, and other adverse effects were assessed using a morning questionnaire, patient's global assessment scale and Wong-Baker faces pain rating. Results : The following result were obtained: 1. After taking 18 g of Ma-huang per day, pulse rate had a significant increase. 2. After taking more than 6 g of Ma-huang per day, palpitation would be increased significantly. 3. After taking more than 18 g of Ma-huang per day, tiredness would be increased significantly. Conclusion: According to the results, 12 g of Ma-huang per day will minimize adverse effects and maximize the potential curative value.

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Construction of MIRD-type Korean Adult Male Phantom and Calculation of Dose Conversion Coefficients for Photon (한국 성인남성 MIRD형 모의피폭체 제작 및 광자 외부피폭 선량환산인자 산출)

  • Park, Sang-Hyun;Lee, Choon-Sik;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.29 no.2
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    • pp.97-104
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    • 2004
  • MIRD-type Korean adult male phantom, 'KMIRD' was constructed to calculate Korean-specific dosimetric quantities for radiation protection consideration. The external shape of KMIRD was based on national physical standard data of Korean. KMIRD has thicket trunk than MIRD5 and arm models divided from trunk. The height and weight of the KMIRD are 171 cm and 63.8 kg. ICRP23 data were referred to constitute organs and tissues of KMIRD. However nine organs were constructed based on Korean reference data provided by Radiation Health Research Institute. In the present study, the MCNPX2.3 Monte Carlo transport code was combined with KMIRD to calculate dose conversion coefficients for photon in the energy range from 0.05 to 10 MeV. The simulated irradiation geometries are broad parallel photon beams in AP, PA, LLAT and RLAT direction. Absorbed dose conversion coefficients were compared with data calculated with MIRD5, MIRD-type phantom based on ICRP23 reference man. In some organs, the discrepancies between two phantoms amount up to nearly 30%. The effective doses conversion coefficients of KMIRD are lower than those of MIRD5. The dose discrepancies between two MIRD-type phantoms ate because of physical differences between Korean and Western, also geometric differences between two phantoms. KMIRD should be revised using the full set of Korean reference data of all organs. The developed MIRD-type Korean adult male phantom can be applied to dose assessment of internal exposure.

Safety of Korean Medicine Treatment in Patients Vaccinated with the AstraZeneca COVID-19 Vaccine (ChAdOx1 nCoV-19/AZD1222): A Case Series (아스트라제네카 코로나19 백신(ChAdOx1 nCoV-19/AZD1222)을 접종한 환자에서 한방 치료의 안전성 : 사례군 연구)

  • Kang, Sung-woo;Hong, Sung-eun;Park, Ji-won;Kwon, Seungwon;Yoon, Sang-hyub;Kim, Kwan-il;Lee, Beom-joon;Jung, Hee-jae
    • The Journal of Internal Korean Medicine
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    • v.42 no.4
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    • pp.590-604
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    • 2021
  • Objectives: The purpose of this study is to examine the safety of Korean medicine treatment in patients vaccinated with the AstraZeneca COVID-19 vaccine (ChAdOx1 nCoV-19/AZD1222). Methods: We investigated patients at Kyung Hee University Korean Medicine Hospital who were vaccinated with the AstraZeneca COVID-19 vaccine between June 1, 2021 and June 30, 2021. The safety of Korean medicine treatment was evaluated by examining adverse events that occurred within seven days of vaccination, including liver function and kidney function testing, assessment of the severity of adverse events, and examination of causality to vaccines and Korean medicine treatment. Results: Eleven patients vaccinated with the first dose of the AstraZeneca COVID-19 vaccine were included. A total of 19 adverse events were reported: 15 systemic adverse events, three local adverse events, and one alanine aminotransferase increase. The most commonly reported systemic adverse events were fatigue (4 cases, 36.4%), headache (4 cases, 36.4%), and myalgia (4 cases, 36.4%). All adverse events were rated below moderate (grade 2) in severity. Systemic and local adverse events were evaluated as definitely related to vaccination and unlikely to be related to Korean medicine treatment, while alanine aminotransferase increase was evaluated as unlikely to be related to either the vaccine or Korean medicine treatment. Aspartate transaminase, Blood urea nitrogen, and creatinine were measured within the reference range after vaccination. Conclusion: Our results suggest that the severity and frequency of adverse events in patients vaccinated with the AstraZeneca COVID-19 vaccine did not increase after Korean medicine treatment.

Comparing Inhaler Use Technique Based on Inhaler Type in Elderly Patients with Respiratory Disease

  • Lee, Ha Youn;Song, Jin Hwa;Won, Ha-Kyeong;Park, Yeonkyung;Chung, Keun Bum;Lim, Hyo-Jeong;Ahn, Young Mee;Lee, Byoung Jun
    • Tuberculosis and Respiratory Diseases
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    • v.84 no.1
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    • pp.46-54
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    • 2021
  • Background: The aim of this study was to investigate inhaler device handling in elderly patients. Inhaler devices with respect to misuse and error correction were also compared. Methods: Inhaler use technique was assessed using standardized checklists at the first visit and 3-month follow-up visit after retraining. The primary outcome was difference in the acceptable use ratio among inhaler devices. Secondary outcomes included differences in error correction, the most common step of misuse, and factors affecting the accuracy of inhaler use. Results: A total of 251 patients (mean age, 76.4 years) were included. The handling of 320 devices was assessed in the study. All patients had been trained before. However, only 24.7% of them used inhalers correctly. Proportions of acceptable use for Evohaler, Respimat, Turbuhaler, Ellipta, and Breezhaler/Handihaler were 38.7%, 50.0%, 61.4%, 60.8%, and 43.2%, respectively (p=0.026). At the second visit, the acceptable use ratio had increased. There were no significant differences among inhaler types (Evohaler, 63.9%; Respimat, 86.1%; Turbuhaler, 74.3%; Ellipta, 64.6%; and Breezhaler/Handihaler, 65.3% [p=0.129]). In multivariate analysis, body mass index, Turbuhaler, and Ellipta showed positive correlations with acceptable use of inhalers, whereas Chronic Obstructive Pulmonary Disease Assessment Test score showed a negative correlation. Conclusion: Although new inhalers have been developed, the accuracy of inhaler use remains low. Elderly patients showed more errors when using pressurized metered-dose inhalers than using dry powder inhalers and soft-mist inhalers. However, there were no significant differences in misuse among inhaler devices after individual training. Results of this study suggests that repeat training is more important than inhaler type.

Biological Dosimetry of In Vitro Irradiation with Radionuclides : Comparison of Whole Blood, Lymphocyte and Buffy Coat Culture (전혈, 림프구와 백혈구 연층 각각의 방사성 동위원소 체외 조사 후 배양을 이용한 생물학적 선량측정)

  • Kim, Jong-Ho;Lee, Dong-Soo;Choi, Chang-Woon;Chung, June-Key;Lee, Myung-Chul;Koh, Chang-Soon;Kim, Chong-Soon;Kim, Hee-Geun;Kang, Duck-Won;Song, Myung-Jae
    • The Korean Journal of Nuclear Medicine
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    • v.29 no.1
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    • pp.125-132
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    • 1995
  • The purpose of this study was to establish mononuclear cell cultures such as lymphocytes or buffy coat for the biological dosimetry of in vitro Irradiation of the radionuclide Tc-99m in order to exclude the effect of residual doses seen in the cultures of whole blood. Biological do simetry of Tc-99m on cultured mononuclear cells at doses ranging from 0.05 to 6.00 Gy, by scoring unstable chromosomal aberrations(Ydr) observed in cultured lymphocytes, were performed using peripheral venous blood of healthy normal person. The results showed that; (1) In vitro irradiation of radioisotope in separated lymphocyte or buffy coat showed trace amount of residual doses of isotope after washing. Residual doses of isotopes are increased in proportion to exposed time and irradiated dose without difference between I-131 and Tc-99m. (2) We obtained these linear-quadratic dose response equations in lymphocyte and buffy coat culture after in vitro irradiation of Tc-99m, respectively (Ydr = 0.001949 $D^2$ +0.006279D + 0.000185; Ydr= 0.002531 $D^2$-0.003274 D+0.003488). In conclusion, the linear quadratic dose-response equation from in vitro irradiation of Tc-99m with lymphocyte and buffy coat culture was thought to be useful for assessing Tc-99m induced biological effects. And mono-nuclear cell cultures seem to be the most appropriate experimental model for the assessment of biological dosimetry of internal irradiation of radionuclides.

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Toxicological Effect of Samultang (Herbal Medicine) Administration in the Pregnant Rats and Fetuses - Focusing on dose-response Relationship - (사물탕의 용량별 투여가 임신 랫드와 태자에 미치는 독성학적 연구)

  • Jeon, Sung-Jin;Shin, Heon-Tae;Kim, Kyung-Tae;Park, Hae-Mo;Lee, Sun-Dong
    • Journal of Society of Preventive Korean Medicine
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    • v.14 no.3
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    • pp.1-12
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    • 2010
  • Objective : Samulatang (herbal description) is much used for women's disease in Korean Traditional Medicine. The aim of this study is to evaluate reproductive toxic effect by Samultang in pregnant rats and fetuses, and ascertain a dose-response relationship Method : Pregnant Sprague-Dawley rats were administered with the Samultang at single, double and quadruple dose for 20 days, orally. Pregnant rats were sacrificed at 20th day of gestation, and observed internal and reproductive organs. Live fetuses of gestation were randomly selected and fixed in 95% ethanol. Fetuses were stained with alcian blue and alizarin red S. We observe maternal body weight,, index associated pregnancy, and skeletal malformations in fetus Result : Maternal body weight of Samultang treated group has increased, side effect was not found in maternal body compared to that of control group. There were no significant difference in internal and reproductive organs. Double concentration administered group had lowest value in number of implantation, live fetuses, implantation rate and delivery rate, Also double concentration administered group showed higher early and late resorption rate than the other group. But, these are not significant. In the sex ratio, number of females, bigger than number of males in all Samultang administered groups. The fetuses of dams treated with Samultang didn't showed external and skeletal malformation. Vertebral and sternal variations were observed in single, double and quadruple concentration administered group but, compared to the control, those variations were insignificant. There were no significant changes in number of ribs, cervical, thoracic, lumber, sacral and caudal vertebrae Conclusion : Samultang is not expected to affect on pregnant rats and fetus about maternal body weight and number of live fetuses. There were no significant changes in organ weight, reproductive organs. Although skeletal variations were showed in vertebrae and sternum, treated groups were shown insignificant changes in skeletal variation

Short-term Evaluation of a Comprehensive Education Program Including Inhaler Training and Disease Management on Chronic Obstructive Pulmonary Disease

  • Yoo, Kwang Ha;Chung, Wou Young;Park, Joo Hun;Hwang, Sung Chul;Kim, Tae-Eun;Oh, Min Jung;Kang, Dae Ryong;Rhee, Chin Kook;Yoon, Hyoung Kyu;Kim, Tae-Hyung;Kim, Deog Kyeom;Park, Yong Bum;Kim, Sang-Ha;Yum, Ho-Kee
    • Tuberculosis and Respiratory Diseases
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    • v.80 no.4
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    • pp.377-384
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    • 2017
  • Background: Proper education regarding inhaler usage and optimal management of chronic obstructive pulmonary disease (COPD) is essential for effectively treating patients with COPD. This study was conducted to evaluate the effects of a comprehensive education program including inhaler training and COPD management. Methods: We enlisted 127 patients with COPD on an outpatient basis at 43 private clinics in Korea. The patients were educated on inhaler usage and disease management for three visits across 2 weeks. Physicians and patients were administered a COPD assessment test (CAT) and questionnaires about the correct usage of inhalers and management of COPD before commencement of this program and after their third visit. Results: The outcomes of 127 COPD patients were analyzed. CAT scores ($19.6{\pm}12.5$ vs. $15.1{\pm}12.3$) improved significantly after this program (p<0.05). Patients with improved CAT scores of 4 points or more had a better understanding of COPD management and the correct technique for using inhalers than those who did not have improved CAT scores (p<0.05). Conclusion: A comprehensive education program including inhaler training and COPD management at a primary care setting improved CAT scores and led to patients' better understanding of COPD management.

Assessment of Inhalation Dose Sensitivity by Physicochemical Properties of Airborne Particulates Containing Naturally Occurring Radioactive Materials (천연방사성물질을 함유한 공기 중 부유입자 흡입 시 입자의 물리화학적 특성에 따른 호흡방사선량 민감도 평가)

  • Kim, Si Young;Choi, Cheol Kyu;Park, Il;Kim, Yong Geon;Choi, Won Chul;Kim, Kwang Pyo
    • Journal of Radiation Protection and Research
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    • v.40 no.4
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    • pp.216-222
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    • 2015
  • Facilities processing raw materials containing naturally occurring radioactive materials (NORM) may give rise to enhanced radiation dose to workers due to chronic inhalation of airborne particulates. Internal radiation dose due to particulate inhalation varies depending on particulate properties, including size, shape, density, and absorption type. The objective of the present study was to assess inhalation dose sensitivity to physicochemical properties of airborne particulates. Committed effective doses to workers resulting from inhalation of airborne particulates were calculated based on International Commission on Radiological Protection 66 human respiratory tract model. Inhalation dose generally increased with decreasing particulate size. Committed effective doses due to inhalation of $0.01{\mu}m$ sized particulates were higher than doses due to $100{\mu}m$ sized particulates by factors of about 100 and 50 for $^{238}U$ and $^{230}Th$, respectively. Inhalation dose increased with decreasing shape factor. Shape factors of 1 and 2 resulted in dose difference by about 18 %. Inhalation dose increased with particulate mass density. Particulate mass densities of $11g{\cdot}cm^{-3}$ and $0.7g{\cdot}cm^{-3}$ resulted in dose difference by about 60 %. For $^{238}U$, inhalation doses were higher for absorption type of S, M, and F in that sequence. Committed effective dose for absorption type S of $^{238}U$ was about 9 times higher than dose for absorption F. For $^{230}Th$, inhalation doses were higher for absorption type of F, M, and S in that sequence. Committed effective dose for absorption type F of $^{230}Th$ was about 16 times higher than dose for absorption S. Consequently, use of default values for particulate properties without consideration of site specific physiochemical properties may potentially skew radiation dose estimates to unrealistic values up to 1-2 orders of magnitude. For this reason, it is highly recommended to consider site specific working materials and conditions and use the site specific particulate properties to accurately access radiation dose to workers at NORM processing facilities.