• Radiation Oncology Journal
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• v.33 no.2
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• pp.89-97
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• 2015

Purpose: To evaluate the treatment results in early stage non-small cell lung cancer patients who have undergone fiducial-less CyberKnife radiosurgery (CKRS). Materials and Methods: From June 2011 to November 2013, 58 patients underwent CKRS at Asan Medical Center for stage I lung cancer. After excluding 14 patients, we retrospectively reviewed the records of the remaining 44 patients. All analyses were performed using SPSS ver. 21. Results: The median age at diagnosis was 75 years. Most patients had inoperable primary lung cancer with a poor pulmonary function test with comorbidity or old age. The clinical stage was IA in 30 patients (68.2%), IB in 14 (31.8%). The mean tumor size was 2.6 cm (range, 1.2 to 4.8 cm), and the tumor was smaller than 2 cm in 12 patients (27.3%). The radiation dose given was 48-60 Gy in 3-4 fractions. In a median follow-up of 23.1 months, local recurrence occurred in three patients (2-year local recurrence-free survival rate, 90.4%) and distant metastasis occurred in 13 patients. All patients tolerated the radiosurgery well, only two patients developing grade 3 dyspnea. The most common complications were radiation-induced fibrosis and pneumonitis. Eight patients died due to cancer progression. Conclusion: The results showed that fiducial-less CKRS shows comparable local tumor control and survival rates to those of LINAC-based SABR or CKRS with a fiducial marker. Thus, fiducial-less CKRS using Xsight lung tracking system can be effectively and safely performed for patients with medically inoperable stage I non-small cell lung cancer without any risk of procedure-related complication.

• 대한두경부종양학회:학술대회논문집
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• 2003.11a
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• pp.239-239
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• 2003

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.167-170
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• 2002

No Abstract, See Full Text

• Progress in Medical Physics
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• v.33 no.4
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• pp.180-180
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• 2022

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.85-85
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• 2006

• Radiation Oncology Journal
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• v.1 no.1
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• pp.69-77
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• 1983

20 cases of midline pineal tumors and 3 suprasellar germinomas received radiation therapy at Yonsei University Medical College, Severance hospital from 1971 to 1982 were reviewed. 12 cases were pathologically proved; 10 germinomas, 1 pineoblastoma, and 1 pineocytoma. 11 cases received radiotherapy without biopsy confirmation. Although treatment fields varied from small field to whole brain irradiation, but not to the spinal cord, most patients received 4000-5000 rads irradiation to the primary tumor site. 17 patients are alive without evidence of disease and 5 year actuarial NED survival is 73.2%. 9 of 10 biopsy proved germinomas and all 6 presumed germinomas are alive and well. Optimum radiation dose, adequate irradiation field, tumor response to radiation observed in serial CT scan and role of radiation therapy in the management of pineal tumors are also discussed.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.32-34
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• 2002

Over the past two decades there has been a tremendous growth in the number of synchrotron radiation facilities in the world and also in Japan. The high flux and brightness radiation which derive from the third generation low emittance rings provide an ideal source for many applications in the medical sciences. The application of synchrotron radiation to medical imaging started in the early 80's in U.S.A, followed by European countries such as Germany and Russia. In Japan, researchs on intravenous coronary angiography started in 1884 at the Institute for High Energy Phisics(KEK) in Tsukuba. At present, it is the only application of syncrotron radiation which is at the stage of human study. In '90s, newer techniques such as phase and refraction contrast imaging appeared which are at the in vitro or animal study stage. Various types of x-ray CT have also been developed for three-dimensional imaging of the subjects. The present status of medical applications of synchrotron radiation in Japan is reviewed.

• Progress in Medical Physics
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• v.33 no.3
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• pp.25-35
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• 2022

Purpose: Planning for radiotherapy relies on implicit estimation of the probability of tumor control and the probability of complications in adjacent normal tissues for a given dose distribution. Methods: The aim of this pilot study was to reconstruct dose-volume histograms (DVHs) from text files generated by the Eclipse treatment planning system developed by Varian Medical Systems and to verify the integrity and accuracy of the dose statistics. Results: We further compared dose statistics for intensity-modulated radiotherapy of the head and neck between the Eclipse software and software developed in-house. The dose statistics data obtained from the Python software were consistent, with deviations from the Eclipse treatment planning system found to be within acceptable limits. Conclusions: The in-house software was able to provide indices of hotness and coldness for treatment planning and store statistical data generated by the software in Oracle databases. We believe the findings of this pilot study may lead to more accurate evaluations in planning for radiotherapy.

• Radiation Oncology Journal
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• v.33 no.2
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• pp.83-88
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• 2015

Purpose: To evaluate the appropriateness of prophylactic inguinal nodal irradiation (PINI), we analyzed patterns of failure in anal cancer patients who were inguinal node-negative at presentation and did not receive PINI. Materials and Methods: We retrospectively reviewed the records of 33 anal cancer patients treated by definitive concurrent chemoradiation therapy (CCRT) between 1994 and 2013. Radiotherapy consisted of a total dose of 44-45 Gy (22-25 fractions in 5 weeks) on the whole pelvis, anus, and perineum. Except inguinal lymphadenopathy was present at initial diagnosis, the entire inguinal chain was not included in the radiation field. In other words, there was no PINI. Results: The median follow-up duration was 50 months (range, 4 to 218 months). Median survival and progression-free survival (PFS) were 57 months (range, 10 to 218 months) and 50 months (range, 4 to 218 months), respectively. Among the survival, the median follow-up duration was 51 months (range, 12 to 218 months). The 5-year overall survival and PFS rates were 93.4% and 88.8%, respectively. Although none of the patients received inguinal node irradiation for prophylactic purposes, there was no inguinal recurrence. Conclusion: Treatment of anal cancer by omitting PINI might be considered in selected patients with clinically uninvolved inguinal nodes.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.571-574
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• 2006

2006년 5월 국제전기기술위원회(International Electrotechnical Commission, IEC) TC62(의료용전기기기기술위원회) SC62A(의료용전기기기 공통특성에 관한 세부분과위원회)에서 의료기기 소프트웨어의 생명주기 프로세스에 관한 국제규격인 IEC 62304, Ed.1을 제정하였다. 전체 내용은 크게 일반적인 요구사항(General requirements)과 소프트웨어 개발과 유지보수에 대한 프로세스(Software development & maintenance process)로 구성되어 있다. 그리고 소프트웨어 개발과 유지보수 프로세스가 진행되는 동안에 기본적으로 확보되어야 하는 소프트웨어 위험관리와 형상관리에 대한 프로세스 Software risk management & configuration management process)를 규정하고, 또한 문제 발생 시 이를 해결하기 위한 소프트웨어 문제 해결 프로세스(Software problem resolution process)를 규정하고 있다. 이는 기존의 정보통신 분야에서 사용되던 소프트웨어 생명주기 프로세스인 ISO/IEC 12207 규격과 외형상 많은 차이를 나타내고 있다. 이에 본 논문에서는 의료기기 소프트웨어의 생명주기 프로세스에 관한 국제규격인 IEC 652304를 분석하여 실제 의료용 소프트웨어 개발 및 유지보수 작업들이 어떠한 방식으로 이루어지는지를 분석하고, 또한 기존의 소프트웨어 생명주기 프로세스인 ISO/IEC 12207 규격과의 차이점을 비교 분석하여 본 규격에 대한 근본적인 활용 방안을 모색하고자 한다.