• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.155-160
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• 2005

Purpose : Many authors have been introduced field in field technique and 3-D conformal radiotherapy that increased the tumor dose as well as decreased the dose of abutting critical organ. These technique have multiple beam direction and small beam segments even below 10 MU(monitor unit)for each field. we have confirmed the influence of low MU on dose output and beam stability. Materials and Methods : To study the dose output, the dose for each field was always 90MU, but it divided into different segment size: 1, 2, 3, 5, 10, 15 segments, 90, 45, 30, 18, 9, 6 MU the measurements were carried out for X-ray energy 4 MV, 6 MV, 10 MV of three LINAC(Varian 600C, 2100C, 2100C, 2100C/D), in addition each measurement was randomly repeated three times for each energy. To study the field symmetry and flatness, X-omat V films were irradiated. After being developed, films were scanned and analyzed using densitometer. Results : Influence of low MU on dose is slightly more increase output about $1.2{\sim}2.9%$ in cGy/mu than 90MU, but may not changed beam quality(flatness or symmetry), Output stability depends on dose rate(PRF)rather than beam energy, field size. Conclusion : Presented result are under the limits(out put<3%, flatness<${\pm}3%$, symmetry<2%). The 3 accelerators are safe to use and to perform conformal radiotherapy treatments in small segments, small MU around 10MU. but Even if the result presented here under the limits, continuous adjustments and periodic QA should be done for use of small MU

• Korean Journal of Medicinal Crop Science
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• v.11 no.3
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• pp.232-235
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• 2003

To investigate effect of fruits of Hovenia dulcis Thunb. on learning ability of ethanol-induced rats, we divided rats into 3 groups; normal, control and sample groups. Control group administered ethanol at a dose 3 g/kg bw. (25 v/v %), while sample group administered the water extract of fruits of Hovenia dulcis Thunb. 30 min. before treating same dose of ethanol as control group orally. All groups were subjected to trials of straight channel on the 1st day and to those of multiple T-maze during the following 3 days. The time required in normal group for the straight channel of the 2nd and the 3rd trials was significantly shorter than that of the 1st, while control group showed no significance. In the time required for the multiple T-maze trials of control group, there were no significance. But in the straight channel or multiple T-maze trials, the sample group showed significant decrease in the time required against control group, and also showed significant decrease in the number of selecting errors.

• Korean Journal of Radiology
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• v.22 no.9
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• pp.1497-1513
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• 2021

The diagnostic and treatment methods of multiple myeloma (MM) have been rapidly evolving owing to advances in imaging techniques and new therapeutic agents. Imaging has begun to play an important role in the management of MM, and international guidelines are frequently updated. Since the publication of 2015 International Myeloma Working Group (IMWG) criteria for the diagnosis of MM, whole-body magnetic resonance imaging (MRI) or low-dose whole-body computed tomography (CT) and ¹⁸F-fluorodeoxyglucose positron emission tomography/CT have entered the mainstream as diagnostic and treatment response assessment tools. The 2019 IMWG guidelines also provide imaging recommendations for various clinical settings. Accordingly, radiologists have become a key component of MM management. In this review, we provide an overview of updates in the MM field with an emphasis on imaging modalities.

• Radiation Oncology Journal
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• v.31 no.2
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• pp.104-110
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• 2013

Purpose: Intensity modulated arc therapy (IMAT) is a form of intensity modulated radiation therapy (IMRT) that delivers dose in single or multiple arcs. We compared IMRT plans versus single-arc field (1ARC) and multi-arc fields (3ARC) IMAT plans in high-risk prostate cancer. Materials and Methods: Sixteen patients were studied. Prostate ($PTV_P$), right pelvic ($PTV_{RtLN}$) and left pelvic lymph nodes ($PTV_{LtLN}$), and organs at risk were contoured. $PTV_P$, $PTV_{RtLN}$, and $PTV_{LtLN}$ received 50.40 Gy followed by a boost to $PTV_B$ of 28.80 Gy. Three plans were per patient generated: IMRT, 1ARC, and 3ARC. We recorded the dose to the PTV, the mean dose ($D_{MEAN}$) to the organs at risk, and volume covered by the 50% isodose. Efficiency was evaluated by monitor units (MU) and beam on time (BOT). Conformity index (CI), Paddick gradient index, and homogeneity index (HI) were also calculated. Results: Average Radiation Therapy Oncology Group CI was 1.17, 1.20, and 1.15 for IMRT, 1ARC, and 3ARC, respectively. The plans' HI were within 1% of each other. The $D_{MEAN}$ of bladder was within 2% of each other. The rectum $D_{MEAN}$ in IMRT plans was 10% lower dose than the arc plans (p < 0.0001). The GI of the 3ARC was superior to IMRT by 27.4% (p = 0.006). The average MU was highest in the IMRT plans (1686) versus 1ARC (575) versus 3ARC (1079). The average BOT was 6 minutes for IMRT compared to 1.3 and 2.9 for 1ARC and 3ARC IMAT (p < 0.05). Conclusion: For high-risk prostate cancer, IMAT may offer a favorable dose gradient profile, conformity, MU and BOT compared to IMRT.

• Clinical and Experimental Reproductive Medicine
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• v.44 no.4
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• pp.232-238
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• 2017

Objective: To determine whether reducing the cetrorelix dose in the antagonist protocol to 0.125 mg had any deleterious effects on follicular development, the number and quality of retrieved oocytes, or the number of embryos, and to characterize its effects on the affordability of assisted reproductive technology. Methods: This randomized controlled study was conducted at the Fertility Unit of Tanta Educational Hospital of Tanta University, the Egyptian Consultants' Fertility Center, and the Qurrat Aien Fertility Center, from January 1 to June 30, 2017. Patients' demographic data, stimulation protocol, costs, pregnancy rate, and complications were recorded. Patients were randomly allocated into two groups: group I (n = 61) received 0.125 mg of cetrorelix (the study group), and group II (n = 62) received 0.25 mg of cetrorelix (the control group). Results: The demographic data were comparable regarding age, parity, duration of infertility, and body mass index. The dose of recombinant follicle-stimulating hormone units required was $2,350.43{\pm}150.76$ IU in group I and $2,366.25{\pm}140.34$ IU in group II, which was not a significant difference (p= 0.548). The duration of stimulation, number of retrieved oocytes, and number of developed embryos were not significantly different between the groups. The clinical and ongoing pregnancy rates likewise did not significantly differ. The cost of intracytoplasmic sperm injection per cycle was significantly lower in group I than in group II (US $ $494.66{\pm}4.079$ vs. US $ $649.677{\pm}43.637$). Conclusion: Reduction of the cetrorelix dose in the antagonist protocol was not associated with any significant difference either in the number of oocytes retrieved or in the pregnancy rate. Moreover, it was more economically feasible for patients in a low-resource country.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.71-71
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• 2003

The study on magnetic field combined radiation therapy, as a new technique to modify the dose distributions using external magnetic field, has been investigated. The goal of the study is to develop the techniques for dose localization, as a particle beam, from the strong magnetic fields. In this study, in order to study the principle of dose deposition in external fields, as a basic approach, we have calculated approximately the paths of traveling electrons in water under external magnetic fields with numerical methods. The calculations are performed for a primary particle by cumulating the steps which are defined as small path lengths which energy loss can be ignored. In this calculation, the energy loss and direction change for a step was calculated by using total stopping power and Lorentz force equation respectively. We have examined the deflected paths of the electron through water as a function of external magnetic field and incident electron s energy. Since we did not take account of the multiple scattering effects for electrons through water, there are errors in this calculation. However, from the results we can explain the principle of dose variation and dose focusing for electron beams under strong magnetic fields in water.

• Radiation Oncology Journal
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• v.37 no.3
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• pp.193-200
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• 2019

Purpose: To explore the role of salvage radiotherapy (RT) for recurrent thymoma as an alternative to surgery. Materials and Methods: Between 2007 and 2015, 47 patients who received salvage RT for recurrent thymoma at Yonsei Cancer Center were included in this study. Recurrent sites included initial tumor bed (n = 4), pleura (n = 19), lung parenchyma (n = 10), distant (n = 9), and multiple regions (n = 5). Three-dimensional conformal and intensity-modulated RT were used in 29 and 18 patients, respectively. Median prescribed dose to gross tumor was 52 Gy (range, 30 to 70 Gy), with equivalent doses in 2-Gy fractions (EQD₂). We investigated overall survival (OS), progression-free survival (PFS), and patterns of failure. Local failure after salvage RT was defined as recurrence at the target volume receiving >50% of the prescription dose. Results: Median follow-up time was 83 months (range, 8 to 299 months). Five-year OS and PFS were 70% and 22%, respectively. The overall response rate was 97.9%; complete response, 34%; partial response, 44.7%; and stable disease, 19.1%. In multivariate analysis, histologic type and salvage RT dose (≥52 Gy, EQD₂) were significantly associated with OS. The high dose group (≥52 Gy, EQD₂) had significantly better outcomes than the low dose group (5-year OS: 80% vs. 59%, p = 0.046; 5-year PFS: 30% vs. 14%, p=0.002). Treatment failure occurred in 34 patients; out-of-field failure was dominant (intra-thoracic recurrence 35.3%; extrathoracic recurrence 11.8%), while local failure rate was 5.8%. Conclusion: Salvage RT for recurrent thymoma using high doses and advanced precision techniques produced favorable outcomes, providing evidence that recurrent thymoma is radiosensitive.

• Tuberculosis and Respiratory Diseases
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• v.68 no.5
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• pp.286-289
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• 2010

A 55-year old woman with advanced stage non-small cell lung cancer was admitted to hospital for the management of severe chest pain, which measured 7 out of 10 on a numerical rating scale (NRS). Despite palliative radiation and the application of multiple epidural blocks, she continued to experience severe cancer pain. We gradually increased the dose of transdermal fentanyl patches from $500{\mu}g/hr$ to $3,650{\mu}g/hr$, for 3 months without any significant side effects. Concomitantly, adjuvant therapy with antidepressants and anticonvulsants were added, decreasing the patient's pain to NRS 3~4 down from 7. After being transferred to a hospice clinic, her chest pain was well-controlled below NRS 4 by means of strong opioid medications, including the highest dose of transdermal fentanyl $4,050{\mu}g/hr$ for more than 16 months.

• Molecular & Cellular Toxicology
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• v.5 no.2
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• pp.165-171
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• 2009

Biomarkers indicating past exposure to radiation have not yet been entirely satisfactory. In this study, we validated several genes reported as radiation response genes, as biomarkers to detect past exposure to radiation in occupationally exposed workers, especially workers in the medical field. A total of 54 radiation workers in hospital were investigated for radiation exposure dose. Their average radiation dose of recent one year was 1.09 mSv ($\pm$1.63) with a 10.63 mSv ($\pm$12.91) cumulative dose. The results of the multiple regression analysis for the various variables indicate that the Hsc70 (P=0.0292) and ORAL (P=0.0045) may be candidate biomarkers for the recent 1 year radiation exposure in radiation workers, whereas AEN (P=0.0334) and PGAMI (P=0.0003) might be for cumulative exposure.

• Journal of Yeungnam Medical Science
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• v.29 no.2
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• pp.129-131
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• 2012

A 70-year-old male came to the emergency room of the authors' hospital because of sudden cardiac arrest due to inferior wall ST elevation myocardial infarction. His coronary angiography revealed multiple severe coronary spasms in his very long left anterior descending artery. After an injection of intracoronary nitroglycerine, his stenosis improved. The cardiac arrest relapsed, however, accompanied by ST elevation of the inferior leads, while the patient was on diltiazem and nitrate medication to prevent coronary spasm. Recovery was not achieved even with cardiac massage, intravenous injection of epinephrine and atropine, and intravenous infusion of nitroglycerine. The patient eventually recovered through high-dose nicorandil intravenous infusion without ST elevation of his inferior leads. Therefore, intravenous infusion of a high dose of nicorandil must be considered a treatment option for cardiac arrest caused by refractory coronary vasospasm.