• 제목/요약/키워드: high dose rate

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Analysis on Fluorine-18 Shielding Efficiency of Double Shield Apron using Acrylic (아크릴을 활용한 이중 차페 Apron의 F-18 차폐 효율 분석)

  • Lee, Gwon-Seong;Jeon, Yeo-Ryeong;Kim, Yong-Min
    • Journal of the Korean Society of Radiology
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    • v.15 no.7
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    • pp.957-964
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    • 2021
  • Fluorine-18 used in PET/CT scans is a radioactive isotope that emits positrons, and high energy annihilation gamma rays and beta rays cause exposure to radiation workers. In this study, as part of a plan to reduce the exposure dose of radiation workers working in the Department of Nuclear Medicine, the cause of the low shielding efficiency of Apron for F-18 was identified, and the effectiveness of the Apron double-shielded with acrylic was evaluated. L-Block, Apron+acrylic, Apron, Acrylic+Apron, and Acrylic five shields are used to measure the dose, and the tendencies were compared by performing a Monte Carlo simulation. As a result, it was found that the shielding rate of Apron double shielded with acrylic was about 4 to 8% higher than that of Apron single shielded. To the extent that it does not significantly affect the user's activity, double-shielded personal protective clothing with an appropriate acrylic thickness could help reduce radiation workers' exposure.

Oral Administration of Lactilactobacillus curvatus LB-P9 Promotes Hair Regeneration in Mice

  • Mikyung Song;Jaeseok Shim;Kyoungsub Song
    • Food Science of Animal Resources
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    • v.44 no.1
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    • pp.204-215
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    • 2024
  • This study was designed to examine the effect of Lactilactobacillus curvatus LB-P9 on hair regeneration. The treatment of LB-P9 conditioned medium increased the proliferation of both hair follicle dermal papilla cells and hair germinal matrix cells (hGMCs). Moreover, the expression levels of hair growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 7 were significantly elevated in hGMCs co-cultured with LB-P9. After time-synchronized depilation, mice were orally administered with either 4×107 colony forming unit (CFU) of LB-P9 (low dose) or 4×108 CFU of LB-P9 (high dose), once daily for 4 weeks. Compared with the vehicle (phosphate-buffered saline)-administrated group, the LB-P9-treated groups exhibited accelerated hair regrowth rate and enhanced hair thickness in a dose-dependent manner. Supporting this observation, both hair follicle numbers and the dermal thickness in skin tissues of the LB-P9-treated groups were increased, compared to those of the vehicle-treated group. These results might be explained by the increased level of β-catenin and number of hair follicle stem cells (CD34+ CD49f+ cells) in the skin tissues of mice administered with LB-P9, compared to the vehicle-treated mice. Also, increased serum levels of hair growth factors such as VEGF and insulin-like growth factor-1, and superoxide dismutase were found in the LB-P9-treated groups, compared to those of the vehicle-treated group. Taken together, these results might demonstrate that the oral administration of LB-P9 promotes hair regeneration by the enhancement of dermal papilla proliferation through the stimulation of hair growth factor production.

Pulmonary passage of canine adipose tissue-derived mesenchymal stem cells through intravenous transplantation in mouse model

  • Jaeyeon Kwon;Mu-Young Kim;Soojung Lee;Jeongik Lee;Hun-Young Yoon
    • Journal of Veterinary Science
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    • v.25 no.3
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    • pp.36.1-36.15
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    • 2024
  • Importance: The intravenous administration of adipose tissue-derived mesenchymal stem cells (AdMSCs) in veterinary medicine is an attractive treatment option. On the other hand, it can result in severe complications, including pulmonary thromboembolism (PTE). Objective: The present study assessed the occurrence of PTE after the intravenous infusion of canine AdMSCs (cAdMSCs) into experimental animals. Methods: Five-week-old male BALB/c hairless mice were categorized into groups labeled A to G. In the control group (A), fluorescently stained 2×106 cAdMSCs were diluted in 200 µL of suspension and injected into the tail vein as a single bolus. The remaining groups included the following: group B with 5×106 cells, group C with 3×106 cells, group D with 1×106 cells, group E with 1×106 cells injected twice with a one-day interval, group F with 2×106 cells in 100 µL of suspension, and group G with 2×106 cells in 300 µL of suspension. Results: Group D achieved a 100% survival rate, while none of the subjects in groups B and C survived (p = 0.002). Blood tests revealed a tendency for the D-dimer levels to increase as the cell dose increased (p = 0.006). The platelet count was higher in the low cell concentration groups and lower in the high cell concentration groups (p = 0.028). A histological examination revealed PTE in most deceased subjects (96.30%). Conclusions and Relevance: PTE was verified, and various variables were identified as potential contributing factors, including the cell dose, injection frequency, and suspension volume.

Anti-SARS-CoV-2 receptor binding domain antibodies after the second dose of Sinovac and AstraZeneca vaccination

  • Marisca Evalina Gondokesumo;Anita Purnamayanti;Puri Safitri Hanum;Winnie Nirmala Santosa;Ardyan Prima Wardhana;Christina Avanti
    • Clinical and Experimental Vaccine Research
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    • v.12 no.3
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    • pp.224-231
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    • 2023
  • Purpose: The Sinovac and AstraZeneca vaccines are the primary coronavirus disease 2019 vaccines in Indonesia. Antibody levels in vaccine-injected individuals will decline substantially over time, but data supporting the duration of such responses are limited. Therefore, this study aims to quantitatively evaluate antibody responses resulting from the completion of Sinovac and AstraZeneca administration in Indonesian adults. Materials and Methods: Participants were divided into two groups based on their vaccine type. Both groups were then assessed on the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (anti-SRBD) concentrations. The anti-SRBD level was measured using Elecsys anti-SARS-CoV-2 S assay and analyzed every month until 3 months after the second vaccination. Results: The results presented significant differences (p=0.000) in immunoglobulin G (IgG) titers among the vaccines' measurement duration, where all samples observed a decrease in IgG titers over time. The mean titer levels of anti-SRBD IgG in the group given Sinovac were high in the first month after vaccination and decreased by 55.7% in 3 months. AstraZeneca showed lesser immune response with a slower decline rate. Adverse effects following immunization (AEFI) showed that systemic reactions are the most reported in both vaccines, with a higher percentage in the second dose of AstraZeneca type vaccines. Conclusion: Sinovac induced more significant titers of anti-SRBD IgG 1 month after the second dose but generated fewer AEFIs. In contrast, AstraZeneca generated more AEFIs, in mild to moderate severity, but provided lower levels of anti-SRBD IgG.

Increase in the Th1-Cell-Based Immune Response in Healthy Workers Exposed to Low-Dose Radiation - Immune System Status of Radiology Staff

  • Karimi, Gholamreza;Balali-Mood, Mahdi;Alamdaran, Seyed-Ali;Badie-Bostan, Hassan;Mohammadi, Elaheh;Ghorani-Azam, Adel;Sadeghi, Mahmood;Riahi-Zanjani, Bamdad
    • Journal of Pharmacopuncture
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    • v.20 no.2
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    • pp.107-111
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    • 2017
  • Objectives: Radiation is one of the most important sources of free radical (such as reactive oxygen species) production, which plays an essential role in the etiology of over hundred diseases. The aim of the study was to investigate some immune parameters and hematological indices in healthy workers of the Radiology Department, University Hospital of Mashhad, Iran. Methods: The study was performed on 50 healthy workers: 30 radiology staff as the case group and 20 laboratory workers as the control group. The radiation dose received by the radiology staff participating in the study was less than the annual maximum permissible level, 50 millisievert. Hematological parameters, lymphocyte proliferation and cytokine production were studied in both groups. Results: Among healthy radiology workers, the hematological indices did not differ statistically; however, their proliferation indices and $IFN-{\gamma}$ levels showed significant increases in parallel with decreases in the IL-4 levels as compared to controls. The immune system of workers exposed to low-dose ionizing radiation was found to be shifted from a Type 2 to a Type 1 response to promote cellular immunity. Conclusion: Based on our data, exposure to low-dose ionizing radiation may decrease the prevalence, frequency, and recurrence of various cancers and infectious diseases because of an increase in Th1-cell-based response, thus leading to more protection of the human body against tumor cells and foreign agents and possibly increased longevity. However, due to high rate of fluoroscopy use for interventional radiology, we suggest continuing research projects on radiation protection and hazards to prevent irreversible damage. As a recommendation, in future studies, radiology staff with a weakened immunity due to high radiation exposure should be considered as good choices to be treated using acupuncture techniques because acupuncture has been demonstrated to enhance the function and the number of immune cells.

Comparative and Feasibility Evaluation of Detection Ability of Relative Dosimeters using CsPbI2Br and CsPbIBr2 Materials in Brachytherapy QA (근접방사선치료 QA에서 CsPbI2Br과 CsPbIBr2를 이용한 상대 선량계들의 검출 능력 비교 및 적용가능성 평가)

  • Seung-Woo Yang;Sung-Kwang Park
    • Journal of the Korean Society of Radiology
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    • v.17 no.3
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    • pp.433-440
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    • 2023
  • High dose rate brachytherapy is a cancer treatment that intensively irradiates radiation to tumors by inserting isotopes with high dose rates into the body. For such a treatment, it is necessary to deliver an accurate dose to the tumor tissue through an accurate treatment plan while delivering only a minimum dose to the normal tissue. Therefore, it is very important to check the location accuracy of the source through accurate Quality Assurance (QA) in clinical practice. However, since the source position is determined using a ruler, automatic radiographer, video monitor, etc. in clinical practice, it yields inaccurate results. In this study, a semiconductor dosimeter using CsPbI2Br and CsPbIBr2 was fabricated. And, in order to analyze whether it is more suitable for the relative QA dosimeter for brachytherapy device among the two materials, the radiation detection ability of each was compared and evaluated. In order to evaluate the radiation detection ability in brachytherapy, the reproducibility and linearity of the two materials were evaluated in 192IR. In the reproducibility evaluation, CsPbI2Br presented a Relative Standard Deviatio(RSD) of 0.98% and CsPbIBr2 presented an RSD of 3.45%. In the linearity evaluation, the coefficient of determination (R2) of CsPbI2Br was presented as 0.9998, and the R2 of CsPbIBr2 was presented as 0.9994. As a result of the evaluation, it was found that CsPbI2Br was more stable in radiation detection while satisfying the evaluation criteria in the dosimeter manufactured in this experiment. Therefore, CsPbI2Br material is suitable for application as a relative dosimeter for radiation detection in brachytherapy devices.

Postoperative chemoradiotherapy in high risk locally advanced gastric cancer

  • Song, Sanghyuk;Chie, Eui Kyu;Kim, Kyubo;Lee, Hyuk-Joon;Yang, Han-Kwang;Han, Sae-Won;Oh, Do-Youn;Im, Seock-Ah;Bang, Yung-Jue;Ha, Sung W.
    • Radiation Oncology Journal
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    • v.30 no.4
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    • pp.213-217
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    • 2012
  • Purpose: To evaluate treatment outcome of patients with high risk locally advanced gastric cancer after postoperative chemoradiotherapy. Materials and Methods: Between May 2003 and May 2012, thirteen patients who underwent postoperative chemoradiotherapy for gastric cancer with resection margin involvement or adjacent structure invasion were retrospectively analyzed. Concurrent chemotherapy was administered in 10 patients. Median dose of radiation was 50.4 Gy (range, 45 to 55.8 Gy). Results: The median follow-up duration for surviving patients was 48 months (range, 5 to 108 months). The 5-year overall survival rate was 42% and the 5-year disease-free survival rate was 28%. Major pattern of failure was peritoneal seeding with 46%. Locoregional recurrence was reported in only one patient. Grade 2 or higher gastrointestinal toxicity occurred in 54% of the patients. However, there was only one patient with higher than grade 3 toxicity. Conclusion: Despite reported suggested role of adjuvant radiotherapy with combination chemotherapy in gastric cancer, only very small portion of the patients underwent the treatment. Results from this study show that postoperative chemoradiotherapy provided excellent locoregional control with acceptable and manageable treatment related toxicity in patients with high risk locally advanced gastric cancer. Thus, postoperative chemoradiotherapy may improve treatment result in terms of locoregional control in these high risk patients. However, as these findings are based on small series, validation with larger cohort is suggested.

Evaluation of Vasodilative Effects on 10 Traditional Herbal Formulas for Treatment of Hypertension (고혈압 치료를 위한 상용하는 한약 처방 10종의 혈관이완 평가)

  • Bumjung Kim
    • The Korea Journal of Herbology
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    • v.39 no.3
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    • pp.69-76
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    • 2024
  • Objectives : Hypertension (high blood pressure), one of the world's major chronic diseases, has a high mortality rate due to its high prevalence and complications, but its control rate is low. The proper management and control through appropriate exercise, diet management, and optimal drug choice can reduce the risk of death from hypertension. Although various antihypertensive drugs are used to treat hypertension, they also have numerous adverse effects. Alongside increased interest in the use of Traditional Herbal Formulas (THF) for hypertension treatment, the purpose of this study was to examine the vasodilative effects of 10 THF in the rat thoracic artery pre-contracted by potassiumchloride (KCl). Methods : THF were extracted with distilled water for 2 hours. The rat thoracic artery was suspended and contracted by KCl in the organ bath which contained 10 ml Krebs Henseleit (KH) buffer. THF extracts were added in a dose-dependent increase (10-1,000 ㎍/mL) to examine vasodilative effects. The vasodilative effects produced by THF were expressed as the percentage in response to KCl-induced contraction. Results : Among the 10 THF, Banhasasim-tang, Buhnsimgieum, Sagunja-tang, and Samul-tang showed vasodilative effects. And, Sipjeondaebo-tang, Ssanghwa-tang, Ojeok-san, Onkyung-tang, Yongdamsagan-tang, and Hyangsayukgunja-tang showed no significant vasodilative effects. Also, in co-administration with amlodipine, Banhasasim-tang showed higher vasodilative effects than amlodipine alone, and Buhnsimgieum showed greater vasodilative effects at low concentrations, but inhibited amlodipine's vasodilative effects at high concentrations. Conclusion : As a result of these studies, they will be expected to provide useful data to establish guidelines of combined administration of THF and western antihypertensive drugs for the treatment of hypertension.

Comparison of Beam Delivery Modes in Prostate Cancer Proton Therapy: A Treatment Planning Comparison Study (전립선암 환자 양성자치료 시 빔 전달방식에 따른 치료계획 비교)

  • Kim, Youn Young;Youm, Doo Seok;Jang, Yo Jong;Kang, Dong Yun;Park, Jeong Hoon
    • The Journal of Korean Society for Radiation Therapy
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    • v.25 no.2
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    • pp.153-158
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    • 2013
  • Purpose: After making two plans, the Double Scattering (DS) Mode and The Pencil Beam Scanning (PBS) Mode, of patients on early prostate cancer, we not only compare the dose conformity and the dose homogeneity by analyzing each DVH, CN and HI, but also evaluate normal structures's sparing effect on each mode. Materials and Methods: Planes about nine patients, who did proton therapy, on prostate cancer was setted using the Eclipse proton external beam planning system. The prescription dose, every $2.5 Gy{\times}28$ fractions=70 Gy, was delivered to the PTV. The CN and the HI were getted by anlazing each DVHs for the DS Plan and the PBS Plan. Also, normal structures' %volumes according to dose of the PBS are campared with those of the DS. Results: The average CN of the PTV is increase 16.63% from DS $0.68{\pm}0.07$ to PBS $0.79{\pm}0.01$, and the average IN of the PTV is decrease -22.66 % from DS $0.12{\pm}0.03$ to PBS $0.09{\pm}0.01$. The PBS has litter %Volumes of normal structures than the DS about every patient except Rectum. The average %Volume of Left Femoral Head receiving ${\geq}30$ Gy shows most high decreasing rate, -79.93%, from DS to PBS and the average %Volume of Rectum receiving ${\geq}70$ Gy shows most low decreasing rate, -3.03%, from DS to PBS. Conclusion: Therefore, the PBS is more effective achieving the dose conformity and the dose Homogeneity than DS, and better to reduce unnecessary dose arriving normal structures, especially the femoral heads.

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Evaluation of Factors Used in AAPM TG-43 Formalism Using Segmented Sources Integration Method and Monte Carlo Simulation: Implementation of microSelectron HDR Ir-192 Source (미소선원 적분법과 몬테칼로 방법을 이용한 AAPM TG-43 선량계산 인자 평가: microSelectron HDR Ir-192 선원에 대한 적용)

  • Ahn, Woo-Sang;Jang, Won-Woo;Park, Sung-Ho;Jung, Sang-Hoon;Cho, Woon-Kap;Kim, Young-Seok;Ahn, Seung-Do
    • Progress in Medical Physics
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    • v.22 no.4
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    • pp.190-197
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    • 2011
  • Currently, the dose distribution calculation used by commercial treatment planning systems (TPSs) for high-dose rate (HDR) brachytherapy is derived from point and line source approximation method recommended by AAPM Task Group 43 (TG-43). However, the study of Monte Carlo (MC) simulation is required in order to assess the accuracy of dose calculation around three-dimensional Ir-192 source. In this study, geometry factor was calculated using segmented sources integration method by dividing microSelectron HDR Ir-192 source into smaller parts. The Monte Carlo code (MCNPX 2.5.0) was used to calculate the dose rate $\dot{D}(r,\theta)$ at a point ($r,\theta$) away from a HDR Ir-192 source in spherical water phantom with 30 cm diameter. Finally, anisotropy function and radial dose function were calculated from obtained results. The obtained geometry factor was compared with that calculated from line source approximation. Similarly, obtained anisotropy function and radial dose function were compared with those derived from MCPT results by Williamson. The geometry factor calculated from segmented sources integration method and line source approximation was within 0.2% for $r{\geq}0.5$ cm and 1.33% for r=0.1 cm, respectively. The relative-root mean square error (R-RMSE) of anisotropy function obtained by this study and Williamson was 2.33% for r=0.25 cm and within 1% for r>0.5 cm, respectively. The R-RMSE of radial dose function was 0.46% at radial distance from 0.1 to 14.0 cm. The geometry factor acquired from segmented sources integration method and line source approximation was in good agreement for $r{\geq}0.1$ cm. However, application of segmented sources integration method seems to be valid, since this method using three-dimensional Ir-192 source provides more realistic geometry factor. The anisotropy function and radial dose function estimated from MCNPX in this study and MCPT by Williamson are in good agreement within uncertainty of Monte Carlo codes except at radial distance of r=0.25 cm. It is expected that Monte Carlo code used in this study could be applied to other sources utilized for brachytherapy.