• Progress in Medical Physics
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• v.26 no.3
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• pp.185-191
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• 2015

As radiation therapy is one of three major cancer treatment methods, many cancer patients get radiation therapy. Because of the invisible and scattering characteristics of radiation, it is impossible to identify the quality and the amount of radiation and secondary cancer could be induced by scattered radiation. Because of advanced technique of radiation therapy and the reasons mentioned above, quality assurance of radiotherapy machine should be performed completely. International organizations such as International Atomic Energy Agency (IAEA), American Association of Physicists in Medicine (AAPM) suggest report of quality assurance to recommend united method of radiotherapy machine quality assurance. Domestic society of medical physics, however, is too small to make such a report, domestic hospitals selectively choose some of contents in global suggestions. As there are no suggestions for domestic hospitals and global suggestions are being updated, we did a survey about quality assurance for radiotherapy machine. The questionnaire is composed of possession of radiotherapy machine, items performed for quality assurance and manpower, etc. 37 of 72 hospitals answered to survey. These results could be used for making domestic standard quality assurance procedure.

• Progress in Medical Physics
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• v.21 no.1
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• pp.99-112
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• 2010

In Republic of Korea, there are many Quality Assurance protocol for general radiation treatment machine such as linac. However, Quality Assurance protocol for radiosurgery treatment system is not ready perfectly. One of the radiation treatment machine for radiosurgery, novalis system needs to suitable Quality Assurance protocol for using it right way during radiation treatment and maintaining suitable accuracy for daily, weekly, monthly and annually periods. Therefore, in this article, we develop Quality Assurance protocol for novalis system. We collected and analysed domestic and foreign novalis Quality Assurance protocol. After that, we selected essential QA items and each tolerance range for developing proper QA protocol, and we made anatomical phantom for execution of selected QA items and evaluation of overall state of QA, and then, we use this measured value as a reference. Quality Assurance items are consisted of Mechanical accuracy QA part and Radiation delivery QA part. Mechanical accuracy QA part is comprised of radiation generation machine part, assistive devices part and multi-leaf collimator part. Radiation delivery QA part is divided into radiation isocenter accuracy and dosimetric evaluation. After that, developed novalis QA tables are made by using these QA items. These novalis QA tables would be used to good standard in order to maintain apt accuracy for radiosurgery in daily, weekly, monthly and annually periods.

• Progress in Medical Physics
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• v.26 no.4
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• pp.294-303
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• 2015

American Association of Physicists in Medicine (AAPM) Published Task Group 40 report which includes recommendations for comprehensive quality assurance (QA) for medical linear accelerator in 1994 and TG-142 report for recommendation for QA which includes procedures such as intensity-modulated radiotherapy (IMRT), stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT) in 2010. Recently, Nuclear Safety and Security Commission (NSSC) published NSSC notification no. 2015-005 which is "Technological standards for radiation safety of medical field". This notification regulate to establish guidelines for quality assurance which includes organization and job, devices, methods/frequency/tolerances and action levels for QA, and to implement quality assurance in each medical institution. For this reason, all of these facilities using medical machine for patient treatment should establish items, frequencies and tolerances for proper QA for medical treatment machine that use the techniques such as non-IMRT, IMRT and SRS/SBRT, and perform quality assurance. For domestic, however, there are lack of guidelines and reports of Korean Society of Medical Physicists (KSMP) for reference to establish systematic QA report in medical institutes. This report, therefore, suggested comprehensive quality assurance system such as the scheme of quality assurance system, which is considered for domestic conditions, based the notification of NSSC and AAPM TG-142 reports. We think that the quality assurance system suggested for medical linear accelerator also help establishing QA system for another high-precision radiation treatment machines.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.330-332
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• 2006

방사선의 조사 유무에 따른 배추와 상추의 발아지수를 평가함으로써 60일 간의 퇴비화 공정에서의 퇴비 품질과 독성을 평가하고자 하였다. 또한 온도, 휘발성 유기화합물, 퇴비 숙성도 등을 평가함으로써 방사선 조사의 퇴비화 에 대한 영향을 분석하였다. 방사선의 높은 에너지는 하수슬러지 내 미생물을 사멸하고 독성유기물을 분해하여 하수슬러지 퇴비 품질을 향상시키는 것으로 확인했다.

• Progress in Medical Physics
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• v.26 no.2
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• pp.59-71
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• 2015

The goal of quality assurance (QA) is to minimize systematic errors in order to maintain the quality of a certain process. Statistical process control (SPC) has been utilized for QA in radiation therapy field since 2005 and is changing QA paradigm. Its purpose is to maintain a process within the given control limits while monitoring of error trends such as variation or dispersion. SPC can be applied to all QA aspects of radiotherapy; however, a medical physicist should have enough knowledge about the application of SPC to QC/QA procedures. In this paper, the author introduce a concept of SPC and review some previously reported studies those used SPC for QA in radiation therapy.

• Journal of radiological science and technology
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• v.11 no.2
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• pp.73-98
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• 1988

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.367-369
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• 2005

방사선 처리에 의한 슬러지의 기초 물성 변화 및 탈수율 증진에 대한 실험을 수행하였다. 또한 슬러지의 자원화를 위하여 슬러지 이용 퇴비를 제조하여 품질을 평가하였다. 방사선을 조사한 슬러지는 입자 내부에 존재하는 일부 수분이 유출되어 최종 탈수 케이크의 함유 수분이 약 7% 정도 감소하였으며, 이는 방사선 조사가 최종 슬러지 발생량을 저감시킬 수 있는 한 가지 방법임을 시사 하여준다. 슬러지를 이용한 퇴비화 실험을 통하여 방사선 처리를 한 퇴비의 품질이 비조사 퇴비에 비하여 퇴비 품질이 향상되었음을 입증하였다.

• Journal of radiological science and technology
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• v.33 no.4
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• pp.387-394
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• 2010

In the field of healthcare, the conventional sterilization treatments have been replaced by irradiation methods which are in accordance with internationally well established quality standards. The quality control in radiation sterilization assures that the absorbed dose of the irradiated material is in agreement with its requirements and standards. The electron beam irradiation requires technical assessments of more process parameters than gamma irradiation does. Korea has witnessed wide uses of electron accelerators since early 2000 but there hasn't been research experiences relating to quality system in accordance with international standards. The new large scale e-beam irradiation system with the specification of 10 MeV, 8 kW was installed and operated in 2008 by Seoul Radiology Services Co. It consists of the electron accelerator, product handling system, safety, documentation and control subsystems into an integrated system to meet the requirement of the Good Manufacturing Practice such as process quality assurance and management of product tracking records. To implement the international standard such as EN ISO11137, it is necessary to understand the purposes aimed in the standard and carry out the tests following the procedures required. This study presented the specification of the e-beam facility and showed what its design requirements and features are. The test results on a variety of process parameters were presented and validated it they are within the required limits.

• Proceedings of the Korean Society of Radiological Science
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• 1996.06a
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• pp.29-30
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• 1996

• Journal of radiological science and technology
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• v.40 no.1
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• pp.1-6
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• 2017

Visual evaluation of chest radiograph images is the most practical and effective method. This study compared the Body Mass Index, waist circumference, and mAs with chest radiographs of 351 women. The Bureau of Radiological Health method was used to evaluate the image quality of chest X-ray images by anatomical and physical methods. The average age of the subjects was $30.17{\pm}4.73$ and the average waist circumference was $66.91{\pm}4.67cm$. The mean Body Mass Index value was $20.21{\pm}2.23$, the mean value of mAs was $3.04{\pm}0.78$, and the mean value of Bureau of Radiological Health was $79.83{\pm}8.45$. When the Body Mass Index value increased, waist circumference and mAs mean value increased. The mean value of Body Mass Index was statistically significant(p<0.05) in Group 4 compared to Groups 1 and 2, with increasing Body Mass Index. Exposure control of the automatic exposure control system is considered to be well performed according to body thickness or Body Mass Index at the time of chest radiography. As the Body Mass Index increases, the thickness of the body increases and the breast thickness of the woman also increases. Therefore, it is considered that the exposure amount is changed by the automatic exposure control device to affect the image quality.