• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.145-153
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• 2021

Purpose: The purpose of this study is to evaluate the ovarian dose during radiation therapy for breast cancer in women of childbearing age through an experiment. The ovarian dose is evaluated by comparing and analyzing between the calculated dose in the treatment planning system according to the treatment technique and the measured dose using a thermoluminescence dosimeter (TLD). The clinical usefulness of lead (Pb) apron is investigated through dose analysis according to whether or not it is used. Materials and Methods: Rando humanoid phantom was used for measurement, and wedge filter radiation therapy, 3D conformal radiation therapy, and intensity modulated radiation therapy were used as treatment techniques. A treatment plan was established so that 95% of the prescribed dose could be delivered to the right breast of the Rando humanoid phantom 3D image obtained using the CT simulator. TLD was inserted into the surface and depth of the virtual ovary of the Rando hunmanoid phantom and irradiated with radiation. The measurement location was the center of treatment and the point moved 2 cm to the opposite breast from the center of the Rando hunmanoid phantom, 5cm, 10cm, 12.5cm, 15cm, 17.5cm, 20cm from the boundary of the right breast to the center of treatment and downward, and the surface and depth of the right ovary. Measurements were made at a total of 9 central points. In the dose comparison of treatment planning systems, two wedge filter treatment techniques, three-dimensional conformal radiotherapy, and intensity-modulated radiation therapy were established and compared. Treatments were compared, and dose measurements according to the use of lead apron were compared and analyzed in intensity-modulated radiation therapy. The measured value was calculated by averaging three TLD values for each point and converting using the TLD calibration value, which was calculated as the point dose mean value. In order to compare the treatment plan value with the actual measured value, the absolute dose value was measured and compared at each point (%Diff). Results: At Point A, the center of treatment, a maximum of 201.7cGy was obtained in the treatment planning system, and a maximum of 200.6cGy was obtained in the TLD. In all treatment planning systems, 0cGy was calculated from Point G, which is a point 17.5cm downward from the breast interface. As a result of TLD, a maximum of 2.6cGy was obtained at Point G, and a maximum of 0.9cGy was obtained at Point J, which is the ovarian dose, and the absolute dose was 0.3%~1.3%. The difference in dose according to the use of lead aprons was from a maximum of 2.1cGy to a minimum of 0.1cGy, and the %Diff value was 0.1%~1.1%. Conclusion: In the treatment planning system, the difference in dose according to the three treatment plans did not show a significant difference from 0.85% to 2.45%. In the ovary, the difference between the Rando humanoid phantom's treatment planning system and the actual measured dose was within 0.9%, and the actual measured dose was slightly higher. This did not accurately reflect the effect of scattered radiation in the treatment planning system, and it is thought that the dose of scattered radiation and the dose taken by CBCT with TLD inserted were reflected in the actual measurement. In dosimetry according to the with or without a lead apron, when a lead apron was used, the closer the distance from the treatment range, the more effective the shielding was. Although it is not clinically appropriate for pregnancy or artificial insemination during radiotherapy, the dose irradiated to the ovaries during treatment is not expected to significantly affect the reproductive function of women of childbearing age after radiotherapy. However, since women of childbearing age have constant anxiety, it is thought that psychological stability can be promoted by presenting the data from this study.

• Journal of Chest Surgery
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• v.40 no.1 s.270
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• pp.45-51
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• 2007

Background: Although echocardiography is usually used for quantitative assessment of left ventricular function, the recently developed 16-slice multidetector computed tomography (MDCT) is not only capable of evaluating the coronary arteries but also left ventricular function. Therefore, the objective of our study was to compare the values of left ventricular function quantified by MDCT to those by echocardiography for evaluation of its regards to clinical applications. Material and Method: From 49 patients who underwent MDCT in our hospital from November 1, 2003 to January 31, 2005, we enrolled 20 patients who underwent echocardiography during the same period for this study. Left ventricular end-diastolic volume index (LVEDVI), left ventricular end-systolic volume index (LVESVI), stroke volume index (SVI), left ventricular mass index (LVMI), and ejection fraction (EF) were analyzed. Result: Average LVEDVI ($80.86{\pm}34.69mL$ for MDCT vs $60.23{\pm}29.06mL$ for Echocardiography, p<0.01), average LVESVI ($37.96{\pm}24.52mL$ for MDCT vs $25.68{\pm}16.57mL$ for Echocardiography, p<0.01), average SVI ($42.90{\pm}15.86mL$ for MDCT vs $34.54{\pm}17.94mL$ for Echocardiography, p<0.01), average LVMI ($72.14{\pm}25.35mL$ for MDCT vs $130.35{\pm}53.10mL$ for Echocardiography, p<0.01), and average EF ($55.63{\pm}12.91mL$ for MOCT vs $59.95{\pm}12.75ml$ for Echocardiography, p<0.05) showed significant difference between both groups. Average LVEDVI, average LVESVI, and average SVI were higher in MDCT, and average LVMI and average EF were higher in echocardiogram. Comparing correlation for each parameters between both groups, LVEDVI $(r^2=0.74,\;p<0.0001)$, LVESVI $(r^2=0.69,\;p<0.0001)$ and SVI $(r^2=0.55,\;p<0.0001)$ showed high relevance, LVMI $(r^2=0.84,\;p<0.0001)$ showed very high relevance, and $EF (r^2=0.45,\;p=0.0002)$ showed relatively high relevance. Conclusion: Quantitative assessment of left ventricular volume and function using 16-slice MDCT showed high relevance compared with echocardiography, therefore may be a feasible assessment method. However, because the average of each parameters showed significant difference, the absolute values between both studies may not be appropriate for clinical applications. Furthermore, considering the future development of MDCT, we expect to be able to easily evaluate the assessment of coronary artery stenosis along with left ventricular function in coronary artery disease patients.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.93-103
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• 1997

Background : Malnutrition is a common finding in patients with chronic obstructive pulmonary disease, especially in the emphysema group. Although the mechanism of malnutrition is not confirmed, it is believed to be a relative deficiency caused by hypermetabolism due to increased energy requirements of the respiratory muscles, rather than a dietary deficiency. Malnutrition in chronic obstructive pulmonary disease is not a merely coincidental finding. It is known that the nutritional status correlates with physiologic parameters including pulmonary function, muscular power, and exercise performance, and is one of the important and independent prognostic factors of the disease. Methods : Patients with chronic obstructive pulmonary disease Yongdong Severance Hospital from May, 1995 to March, 1996 and age-matched healthy control group were studied. Survey of nutritional intake, anthropometric measurements and biochemical tests were done to assess nutritional status. Relationship between nutritional status and FEV1 (forced expiratory volume at one second), which was a significant functional parameter, was assessed. Results : 1) The patient group was consisted of 25 males with mean age of 66.1years and FEV1 of $42{\pm}14%$ of predicted values. The control group was consisted of 26 healthy males with normal pulmonary function, whose mean age was 65.0 years. 2) The ratio of calorie intake/calorie requirement per day was $107{\pm}28%$ in the patient group, and $94{\pm}14%$ in the control group, showing a tendency of more nutritional intake in patient group(B=0.06). 3) There were significant differences between the patient group and control group in percent ideal body weight(92.8% vs 101.6%, p=0.024), body mass index($20.0kg/m^2$ VS $21.9kg/m^2$, p=0.015), and handgrip strength(29.0kg vs 34.3kg, p=0.003). However, there were no significant differences in triceps skinfold thickness, mid-arm muscle circumference, albumin, and total lymphocyte count between two groups. Percentage of underweight population was 40%(10/25) in the patient group, and 15%(4/26) in the control group. 4) The percent ideal body weight, triceps skinfold thickness, and mid-arm muscle circumference had significant correlation with FEV1. Conclusion : The patients with chronic obstructive pulmonary disease showed significant depletion in nutritional parameters such as body weight and peripheral muscle strength, while absolute amount of dietary intake was not insufficient. Nutritional parameters were well correlated with FEV1.

• Journal of Nutrition and Health
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• v.10 no.2
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• pp.59-70
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• 1977

This study was designed to evaluate the changes and improvements in the Korean diet during the last thirty years (since independence in 1945), and to make recommendations for the improvement of their nutritional status, consequently contributing to the physical and mental welfare of the Korean people. The results and recommendations are as follows: 1. The total calorie and carbohydrate intake decreased by $8{\sim}12%$ in the 1970's, as compared with the 1940's and the 1950's. 2. The intake of calcium and vitamiu A increased $30{\sim}50%$ and $20{\sim}60%$ respectively in the 1960's and 1970's as compared with the 1940,s. But this intake level is still lower than the RDA values. 3. The vitamin C intake was somewhat higher in the mountainous and farming areas than in urban areas. 4. In the 1970's, the decrease of untriend intake due to seasonal variation was marked especially for protein, niacin, vitamin $B_1$, and vitamin C. 5. The consumption of protein foods (meats and legumes) increased in an amount of $15{\sim}36g$ per day. There was a marked increase in the intake of meat in farming areas and of milk in urban areas in the 1970's. This increased intake of animal proteins is a very desirable dietary change. 6. The cereal consumption was lowest in urban areal, but there was a general decrease in the intake of the cereal group in the entire area in the 1970's. For the farmers, the intake of cereal food decreased most, from 750 g to 576 g, but cereals still composed a high proportion of the entire diet. 7. Fruits and vegetables showed the highest intake for the urban people, as expected. For the whole area, this food group showed an increase of 8.7% in the 1970's, as compared with the 1960's. 8. The gradual ihcrease in the intake of the fats and oil group was a desirable dietary change. but the absolute amount was too low. 9. A 7% increase in height and a 9% incrrase in weight for growing children and adolescents was observed in the 1970's as compared with the 1940's, but several kinds of deficiency diseases, such as nutritional anemia and dental caries were still apparent in many areas. 10. To improve cur food life and to cope with food shortages faced in Korea, an efficient and nationwide nutrition education program should be implemented. This would maximize efficiency of intake from the limited food sources for a balanced diet. 11. As it is of utmost importance to provide growing children with a desirable physical, sccial mental, and especially nutritional environment, a well-planned and organized school feeding program should be practiced widely and efficiently. 12. Young mothers and pregnant women should be educated on the importance of their children's nutrition, especially for the critical fetal and infancy periods. 13. More thorough and continuous nutritional survey studies on the changes in dietary patterns for the entire nation should be pursued, evaluated and documented. This would Provide a good information guide for future nutritional study programs. 14. It is the nutritionistist's strong desire that national leaders, especially decision makers recognize the fact that improvement of the nutritional status of the People is one of the most economic and preventative ways of improving their physical and mental health. This is closely related to the economic development and strength of the nation.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1308-1314
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• 2006

Purpose : This study aimed to evaluate the usefulness of auditory evoked potential (AEP) in clarifying neuronal development in premature small for gestational age (SGA), and appropriate for gestational age (AGA) infants. Methods : A total of 183 premature infants who were born from August 2002 to July 2005, were examined with AEP. They were divided into three groups; AGA, symmetric-SGA and asymmetric-SGA group. Results : Statistically significant differences in the head circumference were observed in three groups. Among the risk factors, prevalence of hypoglycemia and hypoalbuminemia between AGA and asymmetric SGA infants were significantly different. V absolute peak latency (APL) in the right side of AGA infants was delayed were than that of asymmetric SGA infants. III-V interpeak latency (IPL) of asymmetric SGA infants was delayed more than that of symmetric SGA infants. Moreover, I-V IPL on both sides of symmetric SGA infants was shortened more than that of AGA infants. However, all the results of AEP were within the reference range, according to gestational age. Birth weight of, only asymmetric SGA, was related to the III APL on both sides and the III-V IPL on right side. Conclusion : This study shows that the values of APL and IPL of premature SGA infants are different than that of premature AGA infants. These data could be an indicator in evaluating the neurologic functions of small for gestational age infants.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.57-67
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• 2013

Purpose: Replacing the film which used to be used for checking the set-up of the patient and dosimetry during radiation therapy, more and more EPID equipped devices are in use at present. Accordingly, this article tried to evaluated the accuracy of the position check-up and the usefulness of dosimetry during the use of an electronic portal imaging device. Materials and Methods: On 50 materials acquired with the search of Korea Society Radiotherapeutic Technology, The Korean Society for Radiation Oncology, and Pubmed using "EPID", "Portal dosimetry", "Portal image", "Dose verification", "Quality control", "Cine mode", "Quality - assurance", and "In vivo dosimetry" as indexes, the usefulness of EPID was analyzed by classifying them as history of EPID and dosimetry, set-up verification and characteristics of EPID. Results: EPID is developed from the first generation of Liquid-filled ionization chamber, through the second generation of Camera-based fluoroscopy, and to the third generation of Amorphous-silicon EPID imaging modes can be divided into EPID mode, Cine mode and Integrated mode. When evaluating absolute dose accuracy of films and EPID, it was found that EPID showed within 1% and EDR2 film showed within 3% errors. It was confirmed that EPID is better in error measurement accuracy than film. When gamma analyzing the dose distribution of the base exposure plane which was calculated from therapy planning system, and planes calculated by EDR2 film and EPID, both film and EPID showed less than 2% of pixels which exceeded 1 at gamma values (r%>1) with in the thresholds such as 3%/3 mm and 2%/2 mm respectively. For the time needed for full course QA in IMRT to compare loads, EDR2 film recorded approximately 110 minutes, and EPID recorded approximately 55 minutes. Conclusion: EPID could easily replace conventional complicated and troublesome film and ionization chamber which used to be used for dosimetry and set-up verification, and it was proved to be very efficient and accurate dosimetry device in quality assurance of IMRT (intensity modulated radiation therapy). As cine mode imaging using EPID allows locating tumors in real-time without additional dose in lung and liver which are mobile according to movements of diaphragm and in rectal cancer patients who have unstable position, it may help to implement the most optimal radiotherapy for patients.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.50-59
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• 2006

The risk of fault reactivation in the Gippsland Basin was calculated using the FAST (Fault Analysis Seal Technology) technique, which determines fault reactivation risk by estimating the increase in pore pressure required to cause reactivation within the present-day stress field. The stress regime in the Gippsland Basin is on the boundary between strike-slip and reverse faulting: maximum horizontal stress $({\sim}\;40.5\;Mpa/km)$ > vertical stress (21 Mpa/km) ${\sim}$ minimum horizontal stress (20 MPa/km). Pore pressure is hydrostatic above the Campanian Volcanics of the Golden Beach Subgroup. The NW-SE maximum horizontal stress orientation $(139^{\circ}N)$ determined herein is broadly consistent with previous estimates, and verifies a NW-SE maximum horizontal stress orientation in the Gippsland Basin. Fault reactivation risk in the Gippsland Basin was calculated using two fault strength scenarios; cohesionless faults $(C=0;{\mu}=0.65)$ and healed faults $(C=5.4;\;{\mu}=0.78)$. The orientations of faults with relatively high and relatively low reactivation potential are almost identical for healed and cohesionless fault strength scenarios. High-angle faults striking NE-SW are unlikely to reactivate in the current stress regime. High-angle faults oriented SSE-NNW and ENE-WSW have the highest fault reactivation risk. Additionally, low-angle faults (thrust faults) striking NE-SW have a relatively high risk of reactivation. The highest reactivation risk for optimally oriented faults corresponds to an estimated pore pressure increase (Delta-P) of 3.8 MPa $({\sim}548\;psi)$ for cohesionless faults and 15.6 MPa $({\sim}2262\;psi)$ for healed faults. The absolute values of pore pressure increase obtained from fault reactivation analysis presented in this paper are subject to large errors because of uncertainties in the geomechanical model (in situ stress and rock strength data). In particular, the maximum horizontal stress magnitude and fault strength data are poorly constrained. Therefore, fault reactivation analysis cannot be used to directly measure the maximum allowable pore pressure increase within a reservoir. We argue that fault reactivation analysis of this type can only be used for assessing the relative risk of fault reactivation and not to determine the maximum allowable pore pressure increase a fault can withstand prior to reactivation.

• Progress in Medical Physics
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• v.22 no.2
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• pp.99-105
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• 2011

The purpose of this study is to evaluate the accuracy of IMRT in our clinic from based on TG119 procedure and establish action level. Five IMRT test cases were described in TG119: multi-target, head&neck, prostate, and two C-shapes (easy&hard). There were used and delivered to water-equivalent solid phantom for IMRT. Absolute dose for points in target and OAR was measured by using an ion chamber (CC13, IBA). EBT2 film was utilized to compare the measured two-dimensional dose distribution with the calculated one by treatment planning system. All collected data were analyzed using the TG119 specifications to determine the confidence limit. The mean of relative error (%) between measured and calculated value was $1.2{\pm}1.1%$ and $1.2{\pm}0.7%$ for target and OAR, respectively. The resulting confidence limits were 3.4% and 2.6%. In EBT2 film dosimetry, the average percentage of points passing the gamma criteria (3%/3 mm) was $97.7{\pm}0.8%$. Confidence limit values determined by EBT2 film analysis was 3.9%. This study has focused on IMRT commissioning and quality assurance based on TG119 guideline. It is concluded that action level were ${\pm}4%$ and ${\pm}3%$ for target and OAR and 97% for film measurement, respectively. It is expected that TG119-based procedure can be used as reference to evaluate the accuracy of IMRT for each institution.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.261-277
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• 2017

This study defines influencing sections as the part of the road section where passing vehicles are traveling with the lower speed compared to speed limit due to speed humps. The influencing section was divided into 3 parts; influencing section before the speed hump, interval section, and influencing section after the speed hump. This analysis focused on the changes of each part depending on installation types, vehicle types, and daytime or nighttime. For the interval section, especially, the ratio of distance traveled with lower speed than speed limit to interval section is defined as effective influencing section ratio to be analyzed. Vehicle speed profiles were collected with a speed gun to extract influencing section lengths. The survival analysis was applied and estimated survival functions are compared with each other by several statistical tests. As a consequence, the average length of influencing section on the 50m sequential speed humps was 75.3% longer during the deceleration than that of isolated speed hump, and 18.9% during the acceleration. The effective influencing section ratio for the 30m and 50m sequential speed humps had a small difference of 81.0% and 76.0% while the absolute values of the section that passing speed were less than the speed limit were longer on 50m sequential speed humps, each being 24.3m and 38.0m. Using the log rank test, it was evident that sequential speed humps were more effective to increase the length of influencing sections compared to the isolated speed hump. Vehicle type was the strong factor for influencing section length on the isolated speed hump, but daytime or nighttime was not the effective one. This research result can be used for improving the efficiency selecting the installation point of speed humps for road safety and estimating the standard of the distance between sequential speed humps.

• Progress in Medical Physics
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• v.21 no.2
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• pp.145-152
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• 2010

Inveon PET is a recently developed preclinical PET system for small animal. This study was conducted to measure the performance of Inveon PET as recommended by the NEMA NU 4-2008. We measured the spatial resolution, the sensitivity, the scatter fraction and the NECR using a F-18 source. A 3.432 ns coincidence window was used. A $1\;mm^3$ sized F-18 point source was used for the measurement of spatial resolution within an energy window of 350~625 keV. PET acquisition was performed to obtain the spatial resolution from the center to the 5 cm offset toward the edge of the transverse FOV. Sensitivity, scatter fraction, and NECR were measured within an energy window of 350~750 keV. For measuring the sensitivity, a F-18 line source (length: 12.7 cm) was used with concentric 5 aluminum tubes. For the acquisition of the scatter fraction and the NECR, two NEMA scatter phantoms (rat: 50 mm in diameter, 150 mm in length; mouse: 25 mm in diameter, 70 mm in length) were used and the data for 14 half-lives (25.6 hr) was obtained using the F-18 line source (rat: 316 MBq, mouse: 206 MBq). The spatial resolution of the F-18 point source was 1.53, 1.50 and 2.33 mm in the radial, tangential and axial directions, respectively. The volumetric resolution was $5.43\;mm^3$ in the center. The absolute sensitivity was 6.61%. The peak NECR was 486 kcps @121 MBq (rat phantom), and 1056 kcps @128 MBq (mouse phantom). The values of the scatter fraction were 20.59% and 7.93% in the rat and mouse phantoms, respectively. The performances of the Inveon animal PET scanner were measured in this study. This scanner will be useful for animal imaging.