• Journal of Trauma and Injury
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• v.26 no.3
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• pp.198-206
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• 2013

Purpose: This study was performed to calculate and analyze the effective radiation doses from computed tomography (CT) and radiologic intervention in patients in the emergency department (ED) with trauma critical pathway (CP) activation and further to estimate the lifetime attributable risks (LARs) for the incidence of and mortality from cancers induced by the radiation dose. Methods: Through a retrospective electrical chart review of 104 injured patients who trauma critical pathway were activated from November 2012 to March 2013, we calculated effective radiologic doses by taking the product of the dose-linear product of the scan and the conversion coefficient. After a determination of the image results, we divided the patients into two groups, negative or positive, and calculated the effective dose for each group. With these results, we estimated the LARs for the incidence of and the mortality from cancers by using the table in the Biologic Effects of Ionizing Radiation (BEIR)-VII report. Results: A total of 76 patients were enrolled. The mean age was $49.0{\pm}8.5$ years. The mean injury severity score (ISS) was $12.7{\pm}8.4$. The cumulative effective dose (CED) for individual patients varied from 2.8 mSv to 238.8 mSv, and the mean was $47.6{\pm}39.9$ mSv. The CED in patients with an $ISS{\geq}16$($63.2{\pm}26.6$ mSv) was higher than that of patients whose ISS<16($33.5{\pm}23.1$ mSv) (p<0.001). The CED in patients who were treated with surgery or intervention($69.0{\pm}45.2$ mSv) was higher than that of patients who were treated conservatively($33.6{\pm}22.4$ mSv) (p<0.001). The LARs for cancer incidence and mortality were $328.5{\pm}308.6$ and $189.0{\pm}159.3$ per 100,000 people, respectively. Conclusion: The CED and the LAR for trauma CP-activated patients in the ED were significant, so efforts should be made to decrease the effective dose received by severely injured patients.

• Progress in Medical Physics
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• v.13 no.4
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• pp.187-194
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• 2002

In this work we investigated through Monte Carlo calculations the physical characteristics of the absorbed dose from the Ir-192 source used in brachytherapy The Monte Carlo calculations were performed using the code EGS4, which was extensively modified in order to handle cylindrical sources, phantoms, and energy distributions to suit out own purpose. From the results of the calculations for the $\beta$ -rays, it was found that they contribute on the average 0.02% to The total absorbed dose in the distance range of 0.5-5.0 cm from the source. This is due to the face that, although most of the primary $\beta$ -rays are absorbed in the source and encapsulation material, the resulting low energy braking radiation from them contribute to such a distance. The absorbed dose in the encapsulation material varied on the average from 2.8% for platinum down to 1.1% for iron. The radial dose functions obtained by our Monte Carlo calculations were consistent within $\pm$3% with those of the TG-43 report for the radial distance interval 0.5-10.0 cm from the source. The user code we wrote in this work can be used for other sources of different sizes and so it can be very useful in designing and producing the sources for brachytherapy.

• Progress in Medical Physics
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• v.5 no.2
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• pp.57-68
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• 1994

Purpose : The purposes are to discuss the reason to measure dose distributions of circular small fields for stereotactic radiosurgery based on medical linear accelerator, finding of beam axis, and considering points on dosimetry using home-made small water phantom, and to report dosimetric results of 10MV X-ray of Clinac-18, like as TMR, OAR and field size factor required for treatment planning. Method and material : Dose-response linearity and dose-rate dependence of a p-type silicon (Si) diode, of which size and sensitivity are proper for small field dosimetry, are determined by means of measurement. Two water tanks being same in shape and size, with internal dimension, 30${\times}$30${\times}$30cm$^3$ were home-made with acrylic plates and connected by a hose. One of them a used as a water phantom and the other as a device to control depth of the Si detector in the phantom. Two orthogonal dose profiles at a specified depth were used to determine beam axis. TMR's of 4 circular cones, 10, 20, 30 and 40mm at 100cm SAD were measured, and OAR's of them were measured at 4 depths, d$\sub$max/, 6, 10, 15cm at 100cm SCD. Field size factor (FSF) defined by the ratio of D$\sub$max/ of a given cone at SAD to MU were also measured. Result : The dose-response linearity of the Si detector was almost perfect. Its sensitivity decreased with increasing dose rate but stable for high dose rate like as 100MU/min and higher even though dose out of field could be a little bit overestimated because of low dose rate. Method determining beam axis by two orthogonal profiles was simple and gave 0.05mm accuracy. Adjustment of depth of the detector in a water phantom by insertion and remove of some acryl pates under an auxiliary water tank was also simple and accurate. TMR, OAR and FSF measured by Si detector were sufficiently accurate for application to treatment planning of linac-based stereotactic radiosurgery. OAR in field was nearly independent of depth. Conclusion : The Si detector was appropriate for dosimetry of small circular fields for linac-based stereotactic radiosurgery. The beam axis could be determined by two orthogonal dose profiles. The adjustment of depth of the detector in water was possible by addition or removal of some acryl plates under the auxiliary water tank and simple. TMR, OAR and FSF were accurate enough to apply to stereotactic radiosurgery planning. OAR data at one depth are sufficient for radiosurgery planning.

• Radiation Oncology Journal
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• v.18 no.2
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• pp.150-156
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• 2000

Purpose : Stereotactic radiation therapy (SRT) can deliver highly focused radiation to a small and spherical target lesion with very high degree of mechanical accuracy. For non-spherical and large lesions, however, inclusion of the neighboring normal structures within the high dose radiation volume is inevitable in SRT This is to report the beam shaping using the partial closure of the independent jaw in SRT and the verification of dose calculation and the dose display using a home-made soft ware. Materials and Methods : Authors adopted the idea to partially close one or more independent collimator jaw(5) in addition to the circular collimator cones to shield the neighboring normal structures while keeping the target lesion within the radiation beam field at all angles along the arc trajectory. The output factors (OF's) and the tissue-maximum ratios (TMR's) were measured using the micro ion chamber in the water phantom dosimetry system, and were compared with the theoretical calculations. A film dosimetry procedure was peformed to obtain the depth dose profiles at 5 cm, and they were also compared with the theoretical calculations, where the radiation dose would depend on the actual area of irradiation. Authors incorporated this algorithm into the home-made SRT software for the isodose calculation and display, and was tried on an example case with single brain metastasis. The dose-volume histograms (DVH's) of the planning target volume (PTV) and the normal brain derived by the control plan were reciprocally compared with those derived by the plan using the same arc arrangement plus the independent collimator jaw closure. Results : When using 5.0 cm diameter collimator, the measurements of the OF's and the TMR's with one independent jaw set at 30 mm (unblocked), 15.5 mm, 8.6 mm, and 0 mm from th central beam axis showed good correlation to the theoretical calculation within 0.5% and 0.3% error range. The dose profiles at 5 cm depth obtained by the film dosimetry also showed very good correlation to the theoretical calculations. The isodose profiles obtained on the home-made software demonstrated a slightly more conformal dose distribution around the target lesion by using the independent jaw closure, where the DVH's of the PTV were almost equivalent on the two plans, while the DVH's for the normal brain showed that less volume of the normal brain receiving high radiation dose by using this modification than the control plan employing the circular collimator cone only. Conclusions : With the beam shaping modification using the independent jaw closure, authors have realized wider clinical application of SRT with more conformal dose planning. Authors believe that SRT, with beam shaping ideas and efforts, should no longer be limited to the small spherical lesions, but be more widely applied to rather irregularly shaped tumors in the intracranial and the head and neck regions.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.1
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• pp.69-73
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• 2004

Mucormycosis is an acute opportunistic infection caused by a saprophytic fungus found in soil, decaying fruits and vegetables. Numerous predisposing risk factors are associated with mucormycosis, although most cases have been reported in poorly controlled diabetics or in patients with hematologic malignant conditions. Throughout the history of mucormycosis, from the first case in humans reported in 1885 by Paltauf, through publication by Gregory et al of the first observation of rhino-orbital cerebral mucormycosis in 1943, to the report by Harris in 1955 of the first known survivor, little has changed in the diagnosis and outcome of this disease. Without treatment, the patient may die after an interval ranging from a few days to a few weeks. Regulation of diabetes mellitus and a decrease in the dose of immunosuppressive drugs facilitate the treatment of Mucormycosis. Extensive debridement of craniofacial lesions appears to be very important. intravenous amphotericin B is clearly of value. This is a case report of a patient with mucormycosis in maxilla. He was an uncontrolled DM patient, and for the treatment of intravenous amphotericin B and sequestrectomy were applied.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.1
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• pp.108-125
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• 2014

Although South Korea had managed fishery resources based on elements included in the fishery like fisheries licence, after agreeing on UN Convention on the law in 1999, it became inevitable to adopt TAC that regulates yield. Therefore, currently operating an indecisive system by maintaining the fisheries license system while applying TAC only to some fisheries. However, it became imperative to find ways to improve the current system as it dose not solve problems such as decrease of fishery resources and catch per unit effort, excessive input of fishing boats, rising costs for fishery management, and shortage of fishery population. For those reasons, it is time to review ITQs, which is recognized globally as the most innovative fisheries management system. To adopt the ITQs, it seems necessary to compare how the fisheries act of New Zealand which is currently most successfully operated and Fisheries Resources Management Act of Korea. To do so, in this study, the provisions on TAC of the two countries are compared to analyze the institutional necessity for Korea to adopt ITQs. The following conclusions have been made : First, it will be necessary to gradually expand the species and fisheries for which TAC is enforced, and accumulate correct data on fisheries resources. Second, while forcing traders to obtain license as well, the species and quantity of traded fisheries must be reported separately for cross-checking with the catch reported by the fisheries. Third, the number of observers must be increased and report the species and quantity of the catch to person in charge at the relevant port, and observers must check the report before disembarkation. Fourth, penalty for violating Fisheries resources management act must be enhanced, especially regarding false report of fishery activities and catch.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1276-1280
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• 1996

Because of paucity of primary cardiac tumors, primary cardiac tumors are of much interest to the pathologist, cardiologist and cardiac surgeon. A cardiac chondrosarcoma, which very rare, is presented as follows: This 37 year-old female patient was admitted under the diagnosis of a left atrial tumor(myxoma) on July 3, 1993. Using the CPB, she underwent complete removal of tumor including the atrial septum. And final pathology report was chondrosarcoma. The adjuvant irradiation with total dose of 5040 cGy(28 fractiations for 2 months) and chemotherapy(VP-16 and ifosfamide) was completed. She had no evidence of recurrence until May 2, 1995. when she was admitted due to brain metastasis, which was detected by MRI scan with a tumor free interval for 2 years. A tumor, located around the frontoparital cortex was removed neurosurgern on Sep. 13, 1995 and the final pathology report was also a chondrosarcoma on pathologic exam. The postoperative course was uneventful.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.32-36
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• 2016

Purpose In nuclear medicine examination, $^{131}I$ is widely used in nuclear medicine examination such as diagnosis, treatment, and others of thyroid cancer and other diseases. $^{131}I$ conducts examination and treatment through emission of ${\gamma}$ ray and ${\beta}^-$ ray. Since $^{131}I$ (364 keV) contains more energy compared to $^{99m}Tc$ (140 keV) although it displays high integrated rate and enables quick discharge through kidney, the objective of this study lies in comparing the difference in exposure dose of $^{131}I$ before and after wearing apron when handling $^{131}I$ with focus on 3 elements of external exposure protection that are distance, time, and shield in order to reduce the exposure to technicians in comparison with $^{99m}Tc$ during the handling and administration process. When wearing apron (in general, Pb 0.5 mm), $^{99m}Tc$ presents shield of over 90% but shielding effect of $^{131}I$ is relatively low as it is of high energy and there may be even more exposure due to influence of scattered ray (secondary) and bremsstrahlung in case of high dose. However, there is no special report or guideline for low dose (74 MBq) high energy thus quantitative analysis on exposure dose of technicians will be conducted based on apron wearing during the handling of $^{131}I$. Materials and Methods With patients who visited Department of Nuclear Medicine of our hospital for low dose $^{131}I$ administration for thyroid cancer and diagnosis for 7 months from Jun 2014 to Dec 2014 as its subject, total 6 pieces of TLD was attached to interior and exterior of apron placed on thyroid, chest, and testicle from preparation to administration. Then, radiation exposure dose from $^{131}I$ examination to administration was measured. Total procedure time was set as within 5 min per person including 3 min of explanation, 1 min of distribution, and 1 min of administration. In regards to TLD location selection, chest at which exposure dose is generally measured and thyroid and testicle with high sensitivity were selected. For preparation, 74 MBq of $^{131}I$ shall be distributed with the use of $2m{\ell}$ syringe and then it shall be distributed after making it into dose of $2m{\ell}$ though dilution with normal saline. When distributing $^{131}I$ and administering it to the patient, $100m{\ell}$ of water shall be put into a cup, distributed $^{131}I$ shall be diluted, and then oral administration to patients shall be conducted with the distance of 1m from the patient. The process of withdrawing $2m{\ell}$ syringe and cup used for oral administration was conducted while wearing apron and TLD. Apron and TLD were stored at storage room without influence of radiation exposure and the exposure dose was measured with request to Seoul Radiology Services. Results With the result of monthly accumulated exposure dose of TLD worn inside and outside of apron placed on thyroid, chest, and testicle during low dose $^{131}I$ examination during the research period divided by number of people, statistics processing was conducted with Wilcoxon Signed Rank Test using SPSS Version. 12.0K. As a result, it was revealed that there was no significant difference since all of thyroid (p = 0.345), chest (p = 0.686), and testicle (p = 0.715) were presented to be p > 0.05. Also, when converting the change in total exposure dose during research period into percentage, it was revealed to be -23.5%, -8.3%, and 19.0% for thyroid, chest, and testicle respectively. Conclusion As a result of conducting Wilcoxon Signed Rank Test, it was revealed that there is no statistically significant difference (p > 0.05). Also, in case of calculating shielding rate with accumulate exposure dose during 7 months, it was revealed that there is irregular change in exposure dose for inside and outside of apron. Although the degree of change seems to be high when it is expressed in percentage, it cannot be considered a big change since the unit of accumulated exposure dose is in decimal points. Therefore, regardless of wearing apron during high energy low dose $^{131}I$ administration, placing certain distance and terminating the administration as soon as possible would be of great assistance in reducing the exposure dose. Although this study restricted $^{131}I$ administration time to be within 5 min per person and distance for oral administration to be 1m, there was a shortcoming to acquire accurate result as there was insufficient number of N for statistics and it could be processed only through non-parametric method. Also, exposure dose per person during lose dose $^{131}I$ administration was measured with accumulated exposure dose using TLD rather than through direct-reading exposure dose thus more accurate result could be acquired when measurement is conducted using electronic dosimeter and pocket dosimeter.

• The Journal of Korean Society for Radiation Therapy
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• v.24 no.2
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• pp.197-203
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• 2012

Purpose: In this study, we considerate our radiation therapy process for the breast cancer patient implanted a pacemaker applying the machine movement surgery, shielding, beam selection. Materials and Methods: We perform radiation therapy to a 54 years old, breast cancer patient implanted a pacemaker. The patient underwent a surgery to move the position of a pacemaker to right side breast after consultation with cardiology department. Prescribed dose was 5,040 cGy and daily dose 180 cGy for 28 fractions. The 10 MV photon energy, field size 0/$9.5{\times}20$ cm, half beam and opposing portal irradiation are used. To find out appropriate thickness of shielding board, we carried out an experiment using a solid water phantom ($30{\times}30{\times}7$ cm), a Farmer-type chamber (TN30013, PTW, Germany) and a shielding board (Pb $28{\times}27{\times}0.1$ cm). We calculated expected absorbed dose to te pacemaker with absorb ratio and shielding ratio. In the PTP system (Eclipse, Varian, USA), we figured out how much radiation would be absorbed to the machine with and without shielding. First day of the radiation therapy, we measured head scatter to the pacemaker with MOSFET Dose Verification System (TN-RD-70-W, Medical Canada Ltd., Canada). Results: In the phantom measurement, we found out appropriate thickness was 2 mm of shielding board. In the RTP, when using 2 mm shielding the pacemaker will be absorbed 11.5~38.2 cGy and DVH is 77.3 cGy. In the first day of the therapy, 4.3 cGy was measured so 120.4 cGy was calculated during total therapy. The patient was free from any side effects, and the machine also normally functioned. Conclusion: As the report of association which have public confidence became superannuated, there is lack of data about new machine. We believe that radiation therapy to thiese kind of patients could be done successfully with co-operation, patient-suitable planning, accurate QA, frequent in-vivo dosimetry and monitoring.

• Childhood Kidney Diseases
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• v.21 no.1
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• pp.26-30
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• 2017

Newborn infants with huge and highly vascular sacrococcygeal teratoma (SCT) are frequently subjected to renal hypoperfusion secondary to high-output cardiac failure. Any underlying renal dysfunction is a significant risk factor for the development of contrast-induced nephropathy (CIN). However, reports on CIN in infants are rare. I report here a case of a premature infant born at 28 weeks and 3 days of gestation with a huge SCT who survived preoperative embolization and surgical resection but presented with persistent non-oliguric renal failure that was suggestive of CIN. During radiological intervention, a contrast medium had been administered at about 10 times the manufacturer-recommended dose for pediatric patients. Despite hemodynamic stabilization and normalization of urine output immediately following surgery, the patient's serum creatinine and cystatin-C levels did not return to baseline until 4 months after birth. No signs of reflux nephropathy were observed in follow-up imaging studies. Dosing guidelines for the use of a contrast medium in radiological interventions should be provided for infants or young patients.