전자선 치료시 Lead cut-out 사용에 따른 산란선 감쇄효과

방동완,조정희,윤성익,박재일 대한방사선치료학회 1996 大韓放射線治療技術學會誌 Vol.8 No.1

필름과 BIS 영상장치를 이용한 광/방사선조사야 일치성 비교평가

방동완,석진용,정윤주,최병돈,박진홍,Bang, Dong-Wan,Seok, Jin-Yong,Jeong, Yun-Ju,Choi, Byeong-Don,Park, Jin-Hong 대한방사선치료학회 2004 大韓放射線治療技術學會誌 Vol.16 No.2

목적 : 선형가속기의 정도관리 항목 중 광조사야와 방사선조사야의 일치성 검사는 기존에 필름을 이용하여 측정하였다. 하지만 필름을 이용한 측정은 측정관찰자에 따라 오차가 크게 발생하여 이를 개선하기 위해 BIS(Beam Image System) 영상장치를 이용하여 필름과 조사야 일치성을 비교평가 하고자 하였다. 대상 및 방법 : 선형가속기를 이용하여 필름과 BIS 영상장치에 6, 15MV의 광자선을 조사하여 측정하였다. 조사야는 각각 $50{\times}50,\;100{\times}100,\;200{\times}200mm^2$지었고, 갠트리 각도는 필름을 사용시 $0^{\circ}$에서 측정하였고, BIS 영상장치를 사용시에는 $0^{\circ}$와 $270^{\circ}$에서 측정하였다. 그리고 조사야 일치성 측정은 필름을 사용시 눈금자와 필름 스캐너를 이용하였고, BIS 영상장치에서는 스캔된 광조사야와 방사선조사야의 폭을 X축과 Y축으로 각각 측정하여 그 오차값을 구하였다. 결과 : 필름을 이용한 관찰자의 시각적인 측정에서는 광조사야보다 방사선조사야가 더 크게 측정되었으며, 최대 1.9mm의 오차값을 보였다. 필름 스캐너를 이용한 측정에서도 방사선조사야가 더 크게 측정되었으며, 평균 오차값의 크기는 더 작은 값을 보였다. BIS 영상장치를 이용한 측정에서는 필름 사용시와는 반대로 갠트리 $0^{\circ}$와 $270^{\circ}$에서 광조사야가 방사선조사야보다 더 크게 측정되었고, 최대 0.96mm의 오차값을 보였다. ${\Delta}X$, Y축 모두 허용오차의 범위는 $<{\pm}2mm$로 나타났다. 측정된 평균 ${\Delta}X$, Y 오차값은 시각적인 필름측정, 필름스캐너 측정, BIS 순으로 작게 나타났다. 결론 : 본 연구의 측정결과, 필름을 이용한 시각적인 조사야 일치성 평가시에는 관찰자에 따른 측정오차의 값이 크게 나타날 수 있으므로 정확한 정도관리를 위해서는 세심한 주의로 측정할 것과 필요하다면 다른 영상장치의 도움이나 측정도구의 개발로 정확한 측정이 필요하다 하겠다. Purpose : Film has been the primary tool in coincidence testing between the light field and the radiation field, which constitutes the quality assurance list of a linear accelerator. But there is a great chance of errors being different among the observer when using film. Thus this study set out to use the BIS(Beam Image System) in addition to film in comparing and evaluating coincidence results between the two fields and in searching for the improvement measures. Materials & Methods : Photon beam of 6 and 15MV was exposed to film and the BIS using a linear accelerator. The light and radiation fields were each $50{\times}50,\;100{\times}100,\;and\;200{\times}200mm^2$. The gantry angle was $0^{\circ}$ when using film and $0^{\circ}\;and\;270^{\circ}$ when using the BIS. The devices adopted to test coincidence between the two fields were a ruler and film scanner when using film. With the BIS, the width of the scanned light and radiation fields was measured for errors with setting the X and Y axis. Results : The visual measurements of the observer with film resulted that the radiation field was bigger than the light field and that their maximum error was 1.9mm. The results were the same with the measurements using the film scanner except for the average error, which was less than 1.9mm. On the contrary, the measurements using the BIS showed that the light field was bigger than the radiation field at the gantry angle of $0^{\circ}\;and\;270^{\circ}$. The maximum error was 0.96mm, and the error range was $<{\pm}2mm$ both in the X and Y axis. The average error of ${\Delta}X$, Y was the smallest in the order of the visual film measurements, film scanner measurements, and BIS measurements Conclusion . This requires a careful measurement for accurate quality assurance since errors are much different according to each observer that tests coincidence between visual fields with film. And an observer needs to use another image device or develop a measuring device of his own if it seems necessary for accurate measurements.

치료방사선사의 재교육 프로그램 개발 및 방향

방동완 대한방사선치료학회 2001 大韓放射線治療技術學會誌 Vol.13 No.1

방사선요법을 받는 암환자의 스트레스 지각에 따른 반응과 대처유형의 분석

방동완,BANG DONG WAN 대한방사선사협회 2001 대한방사선사협회지 Vol.27 No.2

I. Purpose : This study is performed to encourage cancer patients to identify, relieve and effectively overcome the stress caused by radiotherapy, by analyzing stress reactions and coping patterns of cancer patients who perceived stress due to radiotherap

다엽 콜리메이터(Multileaf Collimator)와 합금납 차폐물(Lead Alloy Block)의 반음영에 대한 선량분포의 특성비교

방동완,윤성익,조정희,박재일 대한방사선치료학회 1997 大韓放射線治療技術學會誌 Vol.9 No.1

암환자가 지각하는 건강통제위 성격과 삶의 질에 관한 관계연구 -방사선요법을 받는 암환자를 중심으로-

방동완,Bang, Dong-Wan 대한방사선치료학회 2000 大韓放射線治療技術學會誌 Vol.12 No.1

It has been reported that the cancer patient's quality of life is influenced by the perceived health state, self-esteem, health locus of control, social support, whether there is a pain or not, the stage of a disease, the period of a disease, etc, and however, there has been scarcely the research into the fact at home whose cultural and social backgrounds are entire1y different from those of American and European Countries. Accordingly, the author of this thesis performed this study. considering that it is necessary to know the relations between the health locus of control which make it possible to predict the object's behavior related to health and to make plans to induce the object or patient into sound behavior and the quality of life which is closely related to the cancer patient's health, emotion, society, economy, etc. on the whole. This study, a cross-sectional one, includes 135 subjects of $in{\cdot}out$ patients registered at Y University Hospital whose age are more than 20 years, From these patients, data were collected for two weeks through the questionnaire which content concerns about the quality of life and the health locus of control. All the collected data were processed and analyzed through Student's t-test, ANOVA, and the calculation of Pearson Correlation Coefficient, using the SAS program 1. It appeared that the disposition of health locus of control was mostly inclined to the disposition of powerful other health locus of control($28.37{\pm}4.24$), then inclined to internal health locus of control($27.03{\pm}4.17$), and next to chance health locus of control($19.71{\pm}4.97$) By the way. the disposition of powerful other health locus of control appeared a tittle bit higher than internal health locus of control 2. The degree of the quality of life appeared to be 137.54 points in the average of total points and 3.11 in the average evaluation mark. It appeared that the quality of life was most significantly influenced by a factor of 'relations with neighbors' and least significantly influenced by factors of physical conditions and functions. 3. It appeared that the relation between the disposition of health locus of control and the quality of life has nothing to do with the relation between internal health locus of control and the quality of life(r=.1446, P>.05) and also with the relation between the disposition of powerful other health locus of control(r=.0385, P>.05). In conclusion, in the study it has been found out that there is no correlation between the health locus of control and the quality of life, and however it is sound to induce the cancer patient to internal health locus of control. Therefore, it is necessary that under the special circumstances, the cancer patient's behavior should be predicted, thereby inducing the patient to the sound change of his or her behavior. Also in order that the patient enjoys his or her life satisfactorily while living, It is deemed that some kind of multilateral meditation in health and treatment is necessary so that the patient can feel the relief of pain, better health, etc.

뇌종양환자의 방사선치료에 있어서 Vertex Field Verification Film 촬영기법

방동완,조정희,김동욱,박제일 대한방사선치료학회 1994 大韓放射線治療技術學會誌 Vol.6 No.1

방사선요법을 받는 암환자의 스트레스 지각에 따른 반응과 대체유형의 분석

방동완,김진수,박길용,손미숙,BANG DONG WAN,KIM JIN SU,PARK GIL YONG,SON MI SUK 대한방사선치료학회 2001 大韓放射線治療技術學會誌 Vol.13 No.1

I. Purpose This study is performed to encourage cancer patients to identify, relieve and effectively overcome the stress caused by radiotherapy, by analyzing stress reactions and coping patterns of cancer patients who perceived stress due to radiotherapy. II. Materials & Methods The study group was composed of 85 cancer patients of the age 20 or higher who were undergoing radiotherapy in four hospitals located in Seoul and Kyonggi-do. The survey questionnaire was used, which had 161 questions inquiring respondents of general status, perceived stress, stress reactions and coping patterns. The surveyed data were analyzed by a SAS program, which employed descriptive statistics. Pearson Correlation Coefficient, t-test, ANOVA and Stepwised Multiple Regression. III. Results The stress perception and reaction rates were low in cancer patients comparing to patients of the other study. In the coping patterns. the problem-focused coping patterns were significantly higher than emotion-focused coping patterns. The statistically meaningful differences were observed in the stress perception and reactions depending on the time of diagnosis and perceived health level. As for the problem-focused coping patterns, significant differences were found depending on age, marital status, education, income and the number of family members as well as perceived health level of patients. The level of perceived stress and that of stress reactions was found to have positively significant correlation(r=.764, p<.001) while the perceived stress and the problem-focused coping patterns was correlated negatively (r=-.288, p<.01). The stress reactions and the problem-focused coping patterns was found to have negatively significant correlation(r=-.289, p<.01). IV. Conclusion The problem-focused coping behavior, which cooperated with doctors, technologists, nurses and families of cancer patients, is advisable for the cancer patients to overcome uncertainty and uneasiness by effectively release the stress.

고선량율 근접치료의 정도관리

방동완,조정희,박재일,Bang, Dong-Wan,Cho, Chung-Hee,Park, Jae-Il 대한방사선치료학회 1998 大韓放射線治療技術學會誌 Vol.10 No.1

Accurate delivery of doses using a high dose rate(HDR) brachytherapy, remote afterloading system(RALS) depends on knowing the strength of the radioactive source at the time of treatment, the precision and consistency of the timer, and the ability of the unit to position the source at the proper dwell location along the applicator. Periodic Quality Assurance(QA) on HDR machines is a part of the standard protocol of any user. The safety of the patient & staff, positional accuracy, temporal accuracy, and dose delivery accuracy are periodically(weekly, quarterly, monthly) estimated using HDR source(Ir-192), treatment planning devices, measurement devices, and overall treatment devices with regard to treatment delivery. The overall measurement results are estimated successfully and assessed its clinical significance. As a result, our HDR brachytherapy units has been very accurate until now. The QA program protocol permits routine clinical use and provides a high confidence level in the accurate operation of HDR units. Therefore, regular QA of HDR brachytherapy is essential for successful treatment.

조사면내 공동의 존재에 따른 선량분포의 변화측정

조정희,방동완,박재일,Jo, Jeong-Hui,Bang, Dong-Wan,Park, Jae-Il 대한방사선치료학회 1996 大韓放射線治療技術學會誌 Vol.8 No.1

When high energy photon beam is incident upon an air cavity interface the effect of ionization build-up observed . This phenomenon is resulting from the surface layers of the lesions are significant deficiency of electrons reaching the layers because of the replacement, of solid scattering material by the air cavity, that is lack of electronic equilibrium. Measurement have been made in an acrylic phantom with a parallel plate chamber and high energy photon beams, CO-60, 4MV, 6MV and 10MV X-rays have been investigated. The result of our study show that a significant effect was measured and was determined to be very dependent on field size, air cavity dimension and photon energy. The reductions were much larger for 10MV beam, underdosage at the interface was 12, 12.2, 16.9 and $20.6\%$ for the CO-60, 4MV, 6MV and 10MV, respectively. It was found that this non-equilibrium effect at the interface is more severe for the higher energy beams than that of lower energy beams and the larger cavity dimensions the larger beam reductions occur. This problem is of clinical concern when lesions such as carcinoma beyond air cavities are irradiated, such as larynx, glottic and the patients with maxillectomy and ethmoidectomy and so forth.