• Journal of radiological science and technology
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• v.31 no.1
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• pp.11-16
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• 2008

Purpose : The aim of this study was to predict radiation dose at 1 meter with BMI(body mass index) in thyroid cancer patients treated with radio-iodine and provide the efficient guideline in the management of patients. Methods : 140 patients from thyroidectomy for thyroid cancer were enrolled. All subjects under went 150 mCi radio-iodine therapy and performed whole body scan 1 week later. BMI(weight divided by square of height) was calculated to evaluate the amount of fatty tissue indirectly. The radiation dose at 1 meter was measured initially and on 2nd days. the relation of values with BMI were analyzed statically. As for the method of statistical analysis, using Med calc Version 9,2,2,0 Program. Results : (1) The initial effective dose was inversely correlated with the BMI. Significance level was 0.0004. (2) We obtained the following formula from the data of initial effective dose and BMI: Y = -30.91X + 350.4(${\mu}Sv/h$)(Y: initial radiation dose, x: Group). (3) After 21.55 hours, than radiation dose was less than those recommended by ICRP or NRC in 53% of the population. Conclusion : Using BMI, the initial radiation dose and 2nd days dose can be predicted in thyroid cancer patients before radio-iodine therapy. It may be used for predicting the time of discharge and control the isolation room. We were able to predict the radiation exposure after discharge using this calculated value.

• Journal of the Korean Arthroscopy Society
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• v.10 no.1
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• pp.26-32
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• 2006

Purpose: We evaluated the result of the degree of reduction and anterior instability after arthroscopic treatment of tibial spine fractures. Materials and Methods: Thirty-two cases of tibial spine fractures treated with arthroscopic procedure could be evaluated and the mean follow-up period was $18\;(12{\sim}48)$ months. Evaluations included Lachman test, rotatory instability examination and side to side difference (SSD) using KT-2000 arthrometer. The degree of radiologic reduction was classified as accurate reduction, anterior elevation and reduction failure, according to which the degree of anterior instability was measured. Results: There were twenty three cases (71%) of accurate duction, eight cases (25%) of anterior elevation and one case (4%) of education failure. Eight (29%) of twenty eight cases with pull-out method showed anterior elevation. The SSDs of the accurate reduction and the anterior elevation group were 2.0 mm and 2.8 mm, respectively showing no significant difference. However, the percent age of grade 0 Lachman test and SSD less than 3 mm of the accurate reduction group were significantly higher. Conclusion: Accurate reduction is important in reducing anterior instability especially in unstable fractures. Therefore, arthroscopic pull-out method should be performed with great caution to avoid anterior elevation of the fracture fragment.

• Journal of Radiation Protection and Research
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• v.21 no.2
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• pp.125-129
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• 1996

The energy response of HPGe detector for low energy Photons was determined by using three Monte Carlo codes. MCNP4A. EGS4, and CYLTRAN in ITS3. In this study. bare HPGe detector$(100 mm^2{\times}10mm)$ was used and a pencil beam was incident perpendicularly on the center of the detector surface. The photopeak efficiency, $K_{\alpha}$ and $K_{\beta}$ escape fractions were calculated as a function of incident X-ray energies ranging from 12 to 60 keV in 2-keV increments. Since the Compton. elastic. ana penetration fraction were negligible in this energy range. they were ignored in the calculation. Although MCNP. EGS, and CYLTRAN codes calculated slightly different energy response of HPGe detector for low energy Photons, it appears that the three Monte Carlo codes can Predict the low energy Photon scattering Processes accurately. The MCNP results, which are generally known as to be less accurate at low energy ranges than the EGS and ITS results. are comparable to the results of EGS and ITS and are applicable to the calculation of the low energy response data of a detector.

• Journal of Yeungnam Medical Science
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• v.13 no.2
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• pp.261-271
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• 1996

Introduction: Osteoporosis, the most common metabolic bone disorder, is a condition of reduced bone density and increased susceptibility to fractures. Osteoporosis is a major public health problem and a significant cause of morbidity in postmenopausal women. Therefore family physicians as primary care physicians are in a key position for preventing and treating this disorder. So we studied the factors affecting to bone mineral density in postmenopausal women. Materials and Methods: A total of 136 spontaneous postmenopausal women were participated in the study. They have measured spinal bone mineral density by dual energy x-ray absorptiometry from January 1992 to June 1995 at Yeungnam University Hospital. Age, height, weight, age at menarche and menopause, number of child and breast feeding child, history of oral pill ingestion, family history of osteoporosis, amount of milk and coffee ingestion, consumption of tobacco and alcohol and physical activity were assessed by qustionnaire and medical records. Results: The mean age is 55.2 and mean age at menopause is 47.9. Height, weight and physical activity were significantly positive correlated to bone mineral density. But age, duration after menopause and number of child were significantly negative correlated. Also age, height, weight, physical activity and duration after menopause were significantly correlated to % age-matched bone mineral density. In multiple regression analysis, which dependent variable is bone mineral density, duration after menopause, physical activity and weight were significant contributors. Duration after menopause is most the largest contributor. In multiple regression analysis, which dependent variable is % age-matched bone mineral density to adjust the age effect, physical activity and weight were significant contributors. Physical activity is most the largest contributor. Conclusions: Among factors affecting to BMD in postmenopausal women, physical activity and weight were more important factors. Therefore continuous physical activity is significant factor to prevent osteoporosis in postmenopausal women.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.236-241
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• 2005

To investigate the bioactivities of Solidago virga-aurea var. gigantea Mig. Root (SVR), we studied the effect of a SVR methanol extract on the activity of bone metabolism. Spraque-Dawley three-week-old female rats were randomly assigned to groups as follows : non-supplemented rats and supplemented with SVR at 10, 50, 100 mg/kg bw/day. Every week determined weight gain and food intake, urine and blood examination of mineral content of calcium and phosphorus was performed each at experimental periods of 3 and 9 weeks respectively; bone mineral density and bone mineral content were also assayed. There were no significant differences in body weight or feed efficiency ratio levels. However, the biological value of calcium and phosphorus excretion in the group supplemented with SVR extract decreased significantly more than that in the group not supplemented with SVR extract. Also, spine BMD, femur BMC and pelvis BMC per weight were significantly greater on SVR extract supplemented groups than that of the control group. In conclusion, it might be expected that methanol extract of SVR does not impair the growth of rats and may improve bone metabolism in rats.

• Journal of Oral Medicine and Pain
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• v.31 no.4
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• pp.275-281
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• 2006

The purpose of this study was to investigate whether there were any changes in taste function with buring mouth syndrome(BMS). 133 subjects (31 males and 99 females) were included for the study and they were categorized into 2 groups BMS 33 persons, control 100 persons) and investigated in the Dept. of Oral Medicine, Pusan National University Hospital from April,2005 to February,2006. The electrical taste thresholds were measured using an electrogustometer of 4 different sites in oral cavity (tongue tip, tongue lateral, circumvallate papillar and soft palate). The results were as follows : 1. The electrical taste threshold in BMS group was very significantly low. 2. The electrical taste thresholds in male and female of BMS group were significantly lower each other than those of control group 3. The electrical taste threshold of BMS group according to single/multiple lesions and chronicity were not different. 4. After treatment, electrical taste threshold and NAS decreased more significantly.

• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.429-435
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• 2010

Objectives: The aim of this study was to investigate average working lengths of Korean posterior teeth and evaluate validity of endodontic file length. Materials and Methods: The endodontic working length of the posterior teeth of 670 Korean patients were measured than each mean value and standard deviation were investigated than the frequency deviation and standard deviation per each length were calculated. Results: Among the canals of premolar, 66.5% of canal length was marked under 20 mm by endodontic working length and 95.4% could be measured under 22 mm and Among the canals of molars, 95.5% of canal length was marked under 20 mm endodontic working length. Conclusions: With the result of measurement of endodontic working length of premolars of Korean, it suggested that 23 mm endodontic file is more proper than the 21 mm and 25 mm file on the market.

• Progress in Medical Physics
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• v.20 no.4
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• pp.290-297
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• 2009

In case of radiation treatment using small field high-energy photon beams, an accurate dosimetry is a challenging task because of dosimetrically unfavorable phenomena such as dramatic changes of the dose at the field boundaries, dis-equilibrium of the electrons, and non-uniformity between the detector and the phantom materials. In this study, the absorbed dose in the phantom was measured by using an ion chamber and a diode detector widely used in clinics. $GAFCHROMIC^{(R)}$ EBT films composed of water equivalent materials was also evaluated as a small field detector and compared with ionchamber and diode detectors. The output factors at 10 cm depth of a solid phantom located 100 cm from the 6 MV linear accelerator (Varian, 6 EX) source were measured for 6 field sizes ($5{\times}5\;cm^2$, $2{\times}2\;cm^2$, $1.5{\times}1.5\;cm^2$, $1{\times}1\;cm^2$, $0.7{\times}0.7\;cm^2$ and $0.5{\times}0.5\;cm^2$). As a result, from $5{\times}5\;cm^2$ to $1.5{\times}1.5\;cm^2$ field sizes, absorbed doses from three detectors were accurately identified within 1%. Wheres, the ion chamber underestimated dose compared to other detectors in the field sizes less than $1{\times}1\;cm^2$. In order to correct the observed underestimation, a convolution method was employed to eliminate the volume averaging effect of an ion chamber. Finally, in $1{\times}1\;cm^2$ field the absorbed dose with a diode detector was about 3% higher than that with the EBT film while the dose with the ion chamber after volume correction was 1% lower. For $0.5{\times}0.5\;cm^2$ field, the dose with the diode detector was 1% larger than that with the EBT film while dose with volume corrected ionization chamber was 7% lower. In conclusion, the possibility of $GAFCHROMIC^{(R)}$ EBT film as an small field dosimeter was tested and further investigation will be proceed using Monte Calro simulation.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.2
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• pp.115-121
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• 2013

Purpose: Latest linear accelerator and the introduction of new measurement equipment to the agency that the introduction of this equipment in the future, by analyzing the process of confirming the usefulness of the preparation process for applying it in the clinical causes some problems, should be helpful. Materials and Methods: All measurements TrueBEAM STX (Varian, USA) was used, and a file specific to each energy, irradiation conditions, the dose distribution was calculated using a computerized treatment planning equipment (Eclipse ver 10.0.39, Varian, USA). Measuring performance and cause errors in MapCHECK 2 were analyzed and measured against. In order to verify the performance of the MapCHECK 2, 6X, 6X-FFF, 10X, 10X-FFF, 15X field size $10{\times}10$ cm, gantry $0^{\circ}$, $180^{\circ}$ direction was measured by the energy. IGRT couch of the CT values affect the measurements in order to confirm, CT number values : -800 (Carbon) & -950 (COUCH in the air), -100 & 6X-950 in the state for FFF, 15X of the energy field sizes $10{\times}10$, gantry $180^{\circ}$, $135^{\circ}$, $275^{\circ}$ directionwas measured at, MapPHAN allocated to confirm the value of HU were compared, using the treatment planning computer for, Measurement error problem by the sharp edges MapPHAN Learn gantry direction MapPHAN of dependence was measured in three ways. GANTRY $90^{\circ}$, $270^{\circ}$ in the direction of the vertically erected settings 6X-FFF, 15X respectively, and Setting the state established as a horizontal field sizes $10{\times}10$, $90^{\circ}$, $45^{\circ}$, $315^{\circ}$, $270^{\circ}$ of in the direction of the energy-6X-FFF, 15X, respectively, were measured. Without intensity modulated beam of the third open arc were investigated. Results: Of basic performance MapCHECK confirm the attenuation measured by Couch, measured from the measured HU values that are assigned to the MAP-PHAN, check for calculation accuracy for the angled edge of the MapPHAN all come in a range of valid measurement errors do not affect the could see. three ways for the Gantry direction dependence, the first of the meter built into the value of the Gantry $270^{\circ}$ (relative $0^{\circ}$), $90^{\circ}$ (relative $180^{\circ}$), 6X-FFF, 15X from each -1.51, 0.83% and -0.63, -0.22% was not affected by the AP/PA direction represented. Setting the meter horizontally Gantry $90^{\circ}$, $270^{\circ}$ from the couch, Energy 6X-FFF 4.37, 2.84%, 15X, -9.63, -13.32% the difference. By-side direction measurements MapPHAN in value is not within the valid range can not, because that could be confirmed as gamma pass rate 3% of the value is greater than the value shown. You can check the Open Arc 6X-FFF, 15X energy, field size $10{\times}10$ cm $360^{\circ}$ rotation of the dose distribution in the state to look at nearly 90% pass rate to emerge. Conclusion: Based on the above results, the MapPHAN gantry direction dependence by side in the direction of the beam relative dose distribution suitable for measuring the gamma value, but accurate measurement of the absolute dose can not be considered is. this paper, a more accurate treatment plan in order to confirm, Reduce the tolerance for VMAT, such as lateral rotation investigation in order to measure accurate absolute isodose using a combination of IMF (Isocentric Mounting Fixture) MapCHEK 2, will be able to minimize the impact due to the angular dependence.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.97-106
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• 2015

Purpose : This study evaluate the thermal changes caused by use of the chemoport for drug administration and blood sampling during radiofrequency hyperthermia. Materials and Methods : 20cm size of the electrode radio frequency hyperthermia (EHY-2000, Oncotherm KFT, Hungary) was used. The materials of the chemoport in our hospital from currently being used therapy are plastics, metal-containing epoxy and titanium that were made of the diameter 20 cm, height 20 cm insertion of the self-made cylindrical Agar phantom to measure the temperature. Thermoscope(TM-100, Oncotherm Kft, Hungary) and Sim4Life (Ver2.0, Zurich, Switzerland) was compared to the actual measured temperature. Each of the electrode measurement position is the central axis and the central axis side 1.5 cm, 0 cm(surface), 0.5 cm, 1.8 cm, 2.8 cm in depth was respectively measured. The measured temperature is $24.5{\sim}25.5^{\circ}C$, humidity is 30% ~ 32%. In five-minute intervals to measure the output power of 100W, 60 min. Results : In the electrode central axis 2.8 cm depth, the maximum temperature of the case with the unused of the chemoport, plastic, epoxy and titanium were respectively $39.51^{\circ}C$, $39.11^{\circ}C$, $38.81^{\circ}C$, $40.64^{\circ}C$, simulated experimental data were $42.20^{\circ}C$, $41.50^{\circ}C$, $40.70^{\circ}C$, $42.50^{\circ}C$. And in the central axis electrode side 1.5 cm depth 2.8 cm, mesured data were $39.37^{\circ}C$, $39.32^{\circ}C$, $39.20^{\circ}C$, $39.46^{\circ}C$, the simulated experimental data were $42.00^{\circ}C$, $41.80^{\circ}C$, $41.20^{\circ}C$, $42.30^{\circ}C$. Conclusion : The thermal variations were caused by radiofrequency electromagnetic field surrounding the chemoport showed lower than in the case of unused in non-conductive plastic material and epoxy material, the titanum chemoport that made of conductor materials showed a slight differences. This is due to the metal contents in the chemoport and the geometry of the chemoport. And because it uses a low radio frequency bandwidth of the used equipment. That is, although use of the chemoport in this study do not significantly affect the surrounding tissue. That is, because the thermal change is insignificant, it is suggested that the hazard of the chemoport used in this study doesn't need to be considered.