• Radiation Oncology Journal
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• v.8 no.1
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• pp.65-71
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• 1990

Between January,1974 and December 1980, fifty eight patients with locoregional recurrent breast carcinoma who did not have evidence of distant metastasis after initial treatment of surgery with or without adjuvant chemotherapy were treated with radiation therapy. Among them, five patients were excluded from this study because of incomplete record or incomplete treatment. The 5-year overall survival and disease free survival from the time of locoregional recurrence was $27\%\;and\;15\%$ respectively. In univariate analysis of prognostic variables, the clinical stage at initial diagnosis, recur duration, number of recurrence sites, size of recurrences, response to the treatment, remission duration were all found to have no significant effect on survival or disease free survival. On the other hand, menopausal status at initial diagnosis, number of positive node at initial surgery, whether or not the use of adjuvant chemotherapy after initial mastectomy had definite prognositc significance. In multivariate analysis of prognostic variables, remission duration, menopausal status at diagnosis, number of axillary node at mastectomy had definite prognostic significance. On the other hand, remission duration more than 12 months, premenopaus at initial mastectomy, less than four positive axillary lymph nodes at mastectomy predicted a good prognosis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.2
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• pp.185-190
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• 1999

It is difficult to estimate for deterioration of exterior wall by infrared thermography, because of amount of infrared-ray radiation effected by environmental factors such as temperature properties of materials, the outside air and the amount of solar radiation. Therefore we measured the distribution of temperature by times in the same reinforced-concrete structure in order to reduce problems, occasioned by environmental factors, then we analyzed physical influence factors of the infrared thermography. It is the aim of this study to suggest basic data with regard to method of estimation-system for deterioration of exterior wall in reinforced-concrete structures.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.231-237
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• 2012

This paper introduces a gamma-ray measurement system for a transportable tomography which is applicable for an industrial process diagnosis. The gamma-ray measurement system consists of pulse mode operating 72 channel CsI detectors, main AMP-pulse shaper, single channel analyzer, counter and control PC. The CsI crystal is coupled with a PIN diode which is connected to an amplifier and pulse shaper. For a compact design, the amplifier and pulse shaping circuit are included in a single package. 36 sets of CsI detectors are connected to a multi-channel counter through single channel analyzers. A computer controls and collects data from two multi-channel counters. This configuration results in 72 channel counting system in total. The CT rotator and radiation measurement system are controlled by a PC with LabVIEW program. Tomographic data were measured for a phantom by the measurement system and transportable gamma-ray CT. From the experimental data image reconstructions were performed by ML-EM algorithm. The result showed that the CsI detector system can be a suitable component for transportable gamma-ray CT system.

• Journal of radiological science and technology
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• v.30 no.4
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• pp.313-320
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• 2007

There are the Medical Radiation Health and Safety Act(the Patient Radiation Health and Safety Act, the Radiologic Technologist Act), the Medical Laboratory Technologist Act, the Physical Therapy Practice Act, and the Dental Hygienist Act, etc in America. However, Korea has only one Act for a medical radiologic technologist(including radiation therapy technologist, nuclear medicine technologist), medical laboratory technologist, physical therapist, occupational therapy examiner, dental hygienist, and so on. It is the Medical Technologist Act. Therefore, the Medical Radiation Health and Safety Act for a radiologic technologist(including radiation therapy technologist, nuclear medicine technologist) has to be enacted independently in Korea. It is the purpose of this Act to provide for the appropriate certification of persons using radioactive materials, equipment emitting ionizing radiation on humans or performing medical imaging for diagnostic and therapeutic purposes. In Korea, the radiologic technologist is a "fusion technologist" who is a person other than a licensed practitioner as a radiographer, radiation therapist, nuclear medicine technologist, computed tomography technologist, magnetic resonance technologist, mammographer, sonographer, medical dosimetrist, quality management technologist, etc. This Act will have some provisions related to the definitions, reserved title, scope of practice, specialized technologist, application for licensure, radiologic technology council, renewal, continuing education, the radiation control advisory commission, etc. This Act will ensure that quality radiation therapy treatments are delivered and that quality diagnostic information is presented for interpretation, which will lead to accurate diagnosis, treatment and cure. Accurate diagnosis can be provided only when a personnel is properly educated in technique, equipment operation and radiation safety. In the end, this Act will protect the civil right to health. By regulating the personnel responsible for performing those procedures, this Act will mean improved care for patients-higher quality images, improved accuracy, and less exposure to radiation.

• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.2046-2055
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• 2021

This paper analyzed the primary concerns about radiation among the Korean public with a big data analysis of questions posted at the section of "Knowledge iN" on the portal site NAVER in Korea from January 2010 to August 2020. First, we extracted questions about radiation and categorized them into the three categories with TF-IDF analysis: "Medical," "Career Counseling," and "General Interest". The "Medical" category includes questions about radiation diagnosis or treatment. The "Career Counseling" category includes questions about entering college and the prospect of finding jobs in radiation-related fields. The "General Interest" category includes questions about terminology and the basic knowledge of radiation or radioisotopes. Second, we extracted common questions for each category. Finally, we analyzed the temporal change in the numbers of questions for each category to confirm whether there is any correlation between radiation-related events and the number of questions. The analysis results demonstrate that major radiation-related events have little relevance to the number of questions except during March 2011.

• Radiation Oncology Journal
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• v.31 no.3
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• pp.147-154
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• 2013

Purpose: To evaluate the role of salvage radiotherapy (RT) for the treatment of regional lymph node recurrence (RLNR) after radical surgery in advanced gastric cancer. Materials and Methods: We retrospectively analyzed medical records of 26 patients who underwent salvage treatment after diagnosis of RLNR between 2006 and 2011. Patients with peritoneal seeding or distant metastasis were excluded. Eighteen patients received RT with or without chemotherapy and the other 8 did chemotherapy only without RT. A three-dimensional conformal RT was performed with median dose of 56 Gy (range, 44 to 60 Gy). Sixteen patients had fluoropyrimidine-based chemotherapy, 5 did taxane-based chemotherapy, and irinotecan was applied in 4. Results: With a median follow-up of 20 months (range, 5 to 57 months), median overall survival (OS) and progression-free survival (PFS) after diagnosis of RLNR were 29 months and 12 months in the entire patients, respectively. Radiotherapy (p = 0.007) and disease-free interval (p = 0.033) were statistically significant factors for OS in multivariate analysis. Median OS was 36 months in patients who received RT and 16 months in those who did not. Furthermore, delivery of RT (p < 0.001), complete remission after salvage treatment (p = 0.040) and performance status (p = 0.023) were associated with a significantly better PFS. Gastrointestinal toxicities from RT were mild in most patients. Conclusion: Salvage RT combined with systemic chemotherapy may be an effective treatment managing RLNR from advanced gastric cancer.

• Imaging Science in Dentistry
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• v.54 no.3
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• pp.283-288
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• 2024

Purpose: Given the growing use of cone-beam computed tomography (CBCT) scans, this study assessed radiation exposure from these scans in the context of national guidelines and recommended dose limits. Materials and Methods: The current literature was reviewed to quantify the benefit of opportunistic diagnosis of carotid artery calcification relative to the potential risk of radiation-induced cancer. Results: The average radiation from CBCT at its largest field of view and highest resolution possible amounts to a reasonable but still low ionizing radiation exposure. This exposure is comparable to 22 days of background radiation and is notably lower than the radiation exposure from medical CT scans. According to the risk assessment analysis, the risk of stroke events involving internal and external carotid artery calcification (CAC) was 202 and 67 per 100,000 individuals, respectively. In contrast, the estimated risk of radiation-induced cancer associated with CBCT was notably lower, at 0.6 per 100,000. Conclusion: The present study advocates for a comprehensive assessment of CBCT scans encompassing the areas of the internal and external carotid arteries by a knowledgeable professional, given the potential advantages of early detection of vascular abnormalities. Dental professionals who take scans involving these areas need to be mindful of reporting these findings and refer patients to their primary care physician for further investigation.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.592.1-592
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• 2001

Conventional intraoral radiography continues to be the most widely used for the diagnosis of dental caries. But conventional intraoral film has several shortcomings, including processing error, increased radiation dose, etc. Recently, various digital radiographs substitude for conventional radiography to overcome these disadvantages. The digital radiographies are numerous advantages, including elimination of processing errors, lower radiation dose, image quality enhancements such as contrast and density modulation.(omitted)

• Journal of Radiation Protection and Research
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• v.28 no.4
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• pp.263-270
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• 2003

Monte Carlo simulation has been peformed to induce optimized parameters of the detector head of gamma camera for the diagnosis of breast cancer and to evaluate it under the diagnosis condition of the breast cancer. For the simulation, we used Tungsten collimator, having a lattice structured array with holes of $3mm{\times}3mm$ and septal thickness of 0.25 mm, which are corresponding to the pixellated photosensor. For driving optimum parameters we used Trade-Offs procedure between the geometric efficiency and the spatial resolution, varying the detector head components. In order to pre-evaluate the performance of the optimized detector head, we assumed diagnosis condition that the breast tumor is located in the middle of phantom with various sizes and its location is 25 mm from the collimator surface, considering background count caused by radiation sources from other organs. It was shown that the performance of the optimized detector head can be degraded according to the breast cancer size and the background count under real diagnosis conditions of breast cancer. Therefore, it is concluded that the spatial resolution, which is used as an indicator to distinguish the various sizes of breast cancer and is dependent on the characteristic of the detector head, appears to be meaningless in early diagnosis of the breast cancer.

• Journal of Radiation Industry
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• v.18 no.3
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• pp.177-182
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• 2024

The purpose of this study is to develop a CNN based deep learning model that can effectively detect pneumonia by analyzing chest X-ray images of adults over the age of 20 and compare it with VUNO, LUNIT a commercialized AI model. The data of chest X-ray image was evaluate based on accuracy, precision, recall, F1 score, and AUC score. The CNN model recored an accuracy of 82%, precision 76%, recall 99%, F1 score 86%, and AUC score 0.7937. The VUNO model recordded an accuracy of 84%, precision 81%, recall 94%, F1 score 87%, and AUC score 0.8233. The LUNIT model recorded an accuracy of 77%, precision 72%, recall 96%, F1 score 83%, and AUC score 0.7436. As a result of the Confusion Matrix analysis, the CNN model showe FN (3), showing the highest recall rate (99%) in the diagnosis of pneumonia. The VUNO model showed excellent overall perfomance with high accuracy (84%) and AUC score (0.8233), and the LUNIT model showed high recall rate (96%) but the accuracy and precision showed relatively low results. This study will be able to provide basic data useful for the development of a pneumonia diagnosis system by comprehensively considers the perfomance of the medel is necessary to effectively discriminate between penumonia and normal groups.