• International journal of thyroidology
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• v.11 no.2
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• pp.78-81
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• 2018

Lenvatinib, an oral multi-kinase inhibitor, is a valuable treatment option for advanced differentiated thyroid carcinoma. However, severe treatment-related adverse events occur up to 30% of the patients receiving lenvatinib, making it a challenge for clinicians to maintain this drug and therefore affecting the outcome of therapy. Blood vessel related events, such as hypertension or proteinuria, are among the most frequent adverse events. We present a case of 65-year-old man with radioactive iodine refractory papillary thyroid carcinoma with cervical lymph node metastasis and tracheal invasion receiving lenvatinib who developed proteinuria and worsening of hypertension. Management with repeated dose reductions and using supportive medications allowed this patient to continue lenvatinib with his disease stably controlled. Early detection of patients at risk for these adverse events and cautious administration of lenvatinib at appropriate level are crucial in managing patients receiving lenvatinib.

• The Journal of Internal Korean Medicine
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• v.40 no.1
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• pp.154-163
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• 2019

Objective: We report on the administration progression and adverse event of Er-Xian decoction for menopausal hot flushes. A hot flush is a rapid and intense heat-dissipation reaction that involves considerable sweating, enlargement of the peripheral blood vessels, and internal body heat. Er-Xian decoction is a prescription for treating menopausal hot flush symptoms in postmenopausal women. We report administration progression and adverse event of Er-Xian decoction for menopausal hot flush. Methods: We used the Menopause Rating Scale and Menopause-Specific Quality of Life questionnaire to evaluate the progression of hot flushes, and we conducted a literature review to determine the effective dosage of Er-Xian decoction. Result: In all cases, Facial hot flushes and evaluation variables were improved by the administration of EXD. However, in Case 1, a rise of liver function indexes which may be related to EXD administration was observed. Conclusion: Considering that menopausal flushing usually lasts for several years, The resluts are meaningful that the short-term administration of EXD led to improvement of symptoms. In order to further use EXD in the future, it will be necessary to conduct follow-up studies on the subject of safety verification, such as repeated dose toxicity studies.

• Progress in Medical Physics
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• v.25 no.1
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• pp.31-36
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• 2014

We aimed to evaluate the dosimetric characteristics of reproducibility, linearity and dose dependence of optical stimulated luminance dosimeter (OSLD) in the Co-60 Gamma-rays and to analyze with a precedent study in field of the diagnostic radiography and radiotherapy. The reproducibility was 0.76% of the coefficient of variation, the homogeneity was within 1.5% of the coefficient of variation and OSLD had supra-linear response more than 3 Gy. So the correlation between dose and count was fitted by quadratic function. The count depletion by repeated reading was 0.04% per reading regardless of the irradiated dose. And the half time of decay curve according to the irradiated dose was 0.68 min. with 1 Gy, 1.04 min. with 5 Gy, and 1.10 min. with 10 Gy, respectively. In case of annealing for 30 min, the removal rate was 88% with 1 Gy, 90% with 5 Gy, and 92% with 10 Gy, respectively and 99% in case of annealing time for 4 hour. It is feasible to use OSLDs for dose evaluation in Co-60 Gamma-rays when considering the uncertainty on the procedure according to the irradiated dose.

• Progress in Medical Physics
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• v.26 no.1
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• pp.28-35
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• 2015

In this study, we investigated the effects of an iterative reconstruction algorithm and an automatic exposure control (AEC) technique on image quality and radiation dose through phantom experiments with coronary computed tomography (CT) angiography protocols. We scanned the AAPM CT performance phantom using 320 multi-detector-row CT. At the tube voltages of 80, 100, and 120 kVp, the scanning was repeated with two settings of the AEC technique, i.e., with the target standard deviations (SD) values of 33 (the higher tube current) and 44 (the lower tube current). The scanned projection data were reconstructed also in two ways, with the filtered back projection (FBP) and with the iterative reconstruction technique (AIDR-3D). The image quality was evaluated quantitatively with the noise standard deviation, modulation transfer function, and the contrast to noise ratio (CNR). More specifically, we analyzed the influences of selection of a tube voltage and a reconstruction algorithm on tube current modulation and consequently on radiation dose. Reduction of image noise by the iterative reconstruction algorithm compared with the FBP was revealed eminently, especially with the lower tube current protocols, i.e., it was decreased by 46% and 38%, when the AEC was established with the lower dose (the target SD=44) and the higher dose (the target SD=33), respectively. As a side effect of iterative reconstruction, the spatial resolution was decreased by a degree that could not mar the remarkable gains in terms of noise reduction. Consequently, if coronary CT angiogprahy is scanned and reconstructed using both the automatic exposure control and iterative reconstruction techniques, it is anticipated that, in comparison with a conventional acquisition method, image noise can be reduced significantly with slight decrease in spatial resolution, implying clinical advantages of radiation dose reduction, still being faithful to the ALARA principle.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.77-83
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• 2020

This study investigated the radiation protection of therapeutic radiologists. Based on the change in X-ray energy and MU value, the space dose rate in the treatment room after the irradiation was measured. 6MV, 10MV and 15MV photon beams were exposed to radiation inside the treatment room based on 300MU, 600MU and 1000MU using a linear accelerator. And repeated 10 times under the same conditions. As a result of the experiment, 0.1555 μSv/h for 6MV 300MU, 0.157 μSv /h for 300sec, 0.152 μSv/h, 0.156 μSv/h for 600MU, and 0.157 μSv/h 0.152 μSv/h for 1000MU. 300MU of 10MV was 0.49 μSv/h, 0.309 μSv/h, and 0.69 μSv/h, 0.416 μSv/h for 600MU, respectively, and 1000MU was 0.977 μSv/h and 0.478 μSv/h, respectively. The 300MU of 15MV was 3.02 μSv/h, 1.2 μSv/h, 5.459 μSv/h at 600MU, 7.34 μSv/h at 1.836 μSv/h 1000MU, and 2.709 μSv/h. The average spatial dose rate of 6MV was not significantly different from the natural spatial dose rate in the treatment room. High spatial dose rates were measured at 10 MV and 15 MV and were attenuated over time. Therefore, entering the treatment room after a certain period of time (more than 60 seconds) is considered to be effective to prevent the exposure dose of radiation workers.

• Korean Journal of Ecology and Environment
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• v.36 no.4 s.105
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• pp.447-454
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• 2003

Aluminum coagulant was applied to two eutrophic lakes (Lake Sukchon, in Seoul, and a pond on the campus of Kangwon National University), to precipitate suspended particles and phosphate from the water column. Aluminum sulfate (alum) was used for seven treatments and polyaluminum chloride (PAC) was used for one treatment. The effect of treatment varied depending on the dose of alumium coagulant. Particles and phosphate were completely precipitated from the water column with a dose of 10.0 mgAl/l. Partial removal was observed at doses of 3.3 and 1.8 mgAl/l, but not at 0.45 mgAl/l. Therefore, coagulant should be applied at a dose over the threshold in order to remove particles effectively, which seems to be between 1.8 and 10.0 mgAl/l. The length of treatment effect was determined by new inputs of nutrients and particles from external sources. Renewal of pond water by stream water caused recovery of algal growth in Lake Sukchon, and rainfall runoff and ground water pumping caused a return of turbid water in the campus pond. During treatment there was no sign of decreasing pH, or harmful effects on fish or mussels. Aluminum coagulant may be an economically feasible alternative for water quality improvement when the external control of pollutant sources is difficult. However, repeated application is required when there is a renewal of lake water or new input of nutrients.

• Radiation Oncology Journal
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• v.33 no.4
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• pp.276-283
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• 2015

Purpose: We evaluated the efficacy and toxicity of repeated high dose 3-dimensional conformal radiation therapy (3D-CRT) for patients with unresectable hepatocellular carcinoma. Materials and Methods: Between 1998 and 2011, 45 patients received hepatic re-irradiation with high dose 3D-CRT in Samsung Medical Center. After excluding two ineligible patients, 43 patients were retrospectively reviewed. RT was delivered with palliative or salvage intent, and equivalent dose of 2 Gy fractions for ${\alpha}/{\beta}=10Gy$ ranged from $31.25Gy_{10}$ to $93.75Gy_{10}$ (median, $44Gy_{10}$). Tumor response and toxicity were evaluated based on the modified Response Evaluation Criteria in Solid Tumors criteria and the Common Terminology Criteria for Adverse Events (CTCAE) ver. 4.0. Results: The median follow-up duration was 11.2 months (range, 4.1 to 58.3 months). An objective tumor response rate was 62.8%. The tumor response rates were 81.0% and 45.5% in patients receiving ${\geq}45Gy_{10}$ and $<45Gy_{10}$, respectively (p = 0.016). The median overall survival (OS) of all patients was 11.2 months. The OS was significantly affected by the Child-Pugh class as 14.2 months vs. 6.1 months (Child-Pugh A vs. B, p < 0.001), and modified Union for International Cancer Control (UICC) T stage as 15.6 months vs. 8.3 months (T1-3 vs. T4, p = 0.004), respectively. Grade III toxicities were developed in two patients, both of whom received ${\geq}50Gy_{10}$. Conclusion: Hepatic re-irradiation may be an effective and tolerable treatment for patients who are not eligible for further local treatment modalities, especially in patients with Child-Pugh A and T1-3.

• Toxicological Research
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• v.23 no.2
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• pp.151-158
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• 2007

tert-Butyl acetate is an organic solvent used for coatings, industrial cleaning, and surface treatment applications. This study investigated the potential adverse effects of tert-butyl acetate on pregnant dams and embryo-fetal development after maternal exposure on gestational days 6 through 19 in rats. The test chemical was administered to pregnant rats by gavage at dose levels of 0, 500, 1,000, 1,500, and 2,000 mg/kg/day. All dams were subjected to a caesarean section on day 20 of gestation and their fetuses were examined for any external, visceral, and skeletal abnormalities. At 2,000 mg/kg, treatment-related clinical signs, including piloerection, abnormal gait, decreased locomotor activity, loss of fur, reddish tear, anorexia, nasal discharge, vocalization and coma, were observed in a dose-dependent manner. All dams died between the 2nd day and 5th day of treatment due to a severe systemic toxicity. At 1,500 mg/kg, minimal maternal toxicity including an increase in the incidence of decreased locomotor activity and loss of fur, and an increase in the weights of adrenal glands and liver was observed. On the contrary, no significant adverse effect on the embryo-fetal development was detected. There were no adverse effects on either pregnant dams or embryo-fetal development at <1,000 mg/kg. These results show that a 14-day repeated oral dose of tert-butyl acetate in rats caused a minimal maternal toxicity including increases in the incidence of clinical signs and the weights of adrenal glands and liver, but no embryotoxicity and teratogenicity at 1,500 mg/kg/day. Under these experimental conditions, the no-observed-adverse-effect level (NOAEL) of tert-butyl acetate is estimated to be 1,000 mg/kg per day for dams and 1,500 mg/kg per day for embryo-fetal development.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.267-271
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• 1998

It is required to measure air density correction factor at the time of absorbed dose calibration or measurement. In general, thermometer and barometer are widely used for air density correction. However, this can be done using the radioactive check device with better accuracy. The measurements of air density correction were performed by using the radioactive check device, Unidos electrometer, and 0.6 cc Farmer-type ion chamber of PTW under the different environmental conditions. Above experiments were repeated with thermometer and barometer. By comparing the two methods, they were within the difference of 0.2 %. The overall uncertainty for the dose found in thermometer and barometer was 1.2 - 1.6 %, depending upon either one step or two, whereas the overall uncertainty for the radioactive check device was 1.02 %. This method may reduce the possible error which could occur when thermometer and barometer are not calibrated at regular basis.

• Journal of Radiation Protection and Research
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• v.20 no.3
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• pp.181-186
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• 1995

UV irradiation causes a variety of biologic effects on the skin. These effects can be devided to acute reactuons and chronic reacxtions by duration of UV irradiation. Acute reactions are erythema reaction, pigment reactions and changes in epidermal thickness. Among them erythema reaction is most common and conspicuous acute effects of the skin. Upon exposure to sun or artificial UV soures, a faint redness response of skin may begin. Larger exposure causes sunburn reaction which is exaggerated erythema reactionassociated with pain, swelling, vesicle and dulla. Extent and time course of erythema reaction depend upon several factors including wavelength and dose of UVR, skin conditions likeas skin type, site, color, temperature, humidity and environmental factors. Evaluation of erythema erythema induced by UV irradiation is difficult to quantify. Degree of redness of skin are usually estimated by subjective visual evaluation. The lowest exposure dose required to protuce erythema is called minimal erythema dose (mod). Repeated exposures of UVR result in photaging skin. In this condition we can see wrinkling, skin atrophy, dilated blood vessels and keratoses. In sensitive persons photocarcinogenesis is can Be developed on exposed area of skin. Recently skin canser is increasing now in our country. An effective public education and photopreventive method must be developed.