• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.489-492
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• 2014

본 논문에서는 컴퓨터 단층활영(CT)을 통해 발생되는 방사선 노출량의 관리를 위한 시스템의 소프트웨어 설계를 제안한다. 방사선 피폭량은 환자의 각 신체 부위별로 민감성의 차이에 따라 다르기 때문에 방사선의 노출량을 관리할 수 있게 되면 결과적으로 환자의 방사선 피폭량을 추정할 수 있다. 최근 일본 원전의 방사선 누출 사건이 국제적으로 뉴스가 되었고 원전 뿐 만아니라 의료용 방사선 피폭까지 폭넓게 관심이 커지고 있다. 현재 방사선 안전관리는 방사선 관계 종사자에 대해서만 관리되고 있지만, 이제는 환자에 대한 피폭 관리까지 요구되고 있다. 우리나라에서 방사선을 이용한 검사와 시술이 증가하여 이에 따른 의료 피폭이 증가하였으나 의료 기관에서는 환자에게 가해지는 방사선 피폭 수치를 알지 못하는 실정이다. 따라서 의료 기관에서 환자의 방사선 피폭을 관리할 수 있는 시스템이 필요하다. 본 논문에서는 의료 기관에서 방사선을 이용하는 대표적인 촬영 도구인 CT의 방사선 노출량을 관리할 수 있는 소프트웨어 설계를 제시한다. 방사선의 노출량을 확인하고 선량의 한도를 설정함으로써 환자의 의료 피폭량을 최적화 하는데 도움이 되고자 한다.

• 한국의학물리학회지:의학물리
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• 제22권4호
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• pp.178-183
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• 2011

본 연구에서는 토모테라피를 이용한 폐종양의 방사선수술 치료계획을 수립한 후 기존의 선형가속기를 사용하였을 경우와 비교, 분석하여 선량분포 측면에서 유효성 및 타당성을 살펴보았다. 종양의 움직임이 5 mm 이하인 10명의 환자 CT 영상을 대상으로 기존의 선형가속기를 이용한 세기조절방사선수술에서와 동일한 처방선량과 동일한 조건의 중요장기 선량제한치로 토모테라피 치료계획을 수립한 후 선량분포를 비교하였다. 토모테라피를 이용한 결과에서도 기존의 선형가속기를 이용한 세기조절방사선수술과 동일하게 중요장기의 선량제한치를 충족시키면서 GTV에 처방선량을 부여할 수있음을 확인하였다. 방사선조사로 인한 폐의 정상조직합병증확률과 종양 반대편 폐의 등가균일선량 측면에서는 토모테라피가 기존 선형가속기보다 상대적으로 더 우수한 결과를 보였으나, 종양 내 치료선량 분포의 균일도에서는 기존 선형 가속기가 더 양호한 결과를 보였다. 치료 빔 전달 시간측면에서는 토모테라피가 기존 선형가속기 경우보다 2배 이상의 시간이 소요되었다. 이와 같은 본 연구의 결과 분석을 통해 폐종양 부위의 움직임이 적은 경우, 환자의 상태와 선량분포의 적합성 등을 고려한 최적의 치료계획을 세운다면 토모테라피를 사용하는 방사선 수술이 유효성 및 타당성이 있음을 확인할 수 있었다.

• Radiation Oncology Journal
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• 제34권2호
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• pp.88-95
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• 2016

Purpose: The purpose of this study was to estimate the clinical utilization of radiation therapy (RT) in Korea between 2009 and 2013. Materials and Methods: We analyzed open claims data from the Health Insurance Review and Assessment Service. The subjects were patients who had diagnostic codes C00-C97 or D00-D48 according to the 10th revision of the International Classification of Diseases, with procedure codes indicating RT treatment. Results: The total number of patients who received RT in 2009, 2010, 2011, 2012, and 2013 were 45,571, 49,593, 54,671, 59,172, and 61,485, respectively. Among them, the total numbers of male and female patients were 20,780/24,791 in 2009, 22,711/26,882 in 2010, 24,872/29,799 in 2011, 27,101/32,071 in 2012, and 27,941/33,544 in 2013. The five cancers that were most frequently treated with RT between 2009 and 2012 were breast, lung, colorectal, liver, and uterine cervical cancers. However, the fifth most common cancer treated with RT that replaced uterine cervical cancer in 2013 was prostate cancer. The three leading types of cancer among the male patients were lung, colorectal, and liver cancers, whereas in female patients, they were breast, uterine cervical, and lung cancers. The type of cancer most commonly treated by RT was cancer of the central nervous system in patients aged 20 years or less, breast cancer in patients aged 30-50 years, and lung cancer in patients aged 60 years or more. Conclusion: Data from this study provided the clinical utilization of RT in Korea between 2009 and 2013.

• Radiation Oncology Journal
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• 제13권1호
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• pp.79-85
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• 1995

Purpose : To assess the efficacy of recombinant human granulocyte-macrophage colony-stimulating factor(GM-CSF) in the neutropenia by radiotherapy. Materials and Methods : Eleven patients with various solid tumor were treated with a daily subcutaneous dose of GM-CSF(3-7microgram/kg) for 5days during the radiotherapy. Before and during the course of the study all the patients were monitored by the recording of physical examination, the complete blood count with differential and reticulocyte count and liver function test. Eight patients received prior or concurrent chemotherapy. Results : In 10 patients, the neutrophilic nadir was significantly elevated and the lenght of time that Patients had a neutrophil count below $10^3/mm^3$ a threshold known to be critical to acquiring infective complications was shortened following GM-CSF injection. A significant rise (two fold or greater) of neutrophil count was seen in 10 of 11 patients. In most patients, discontinuation of GM-CSF resulted in a prompt return of granulocyte counts toward baseline. However the neutrophil count remained elevated over $10^3/mm^3$ during radiation therapy, and radiotherapy delays were avoided. Other peripheral blood components including monocytes and platelets also increased after GM-CSF treatment. No significant toxicity was encountered with subcutaneous GM-CSF treatment. Conclusion : GM-CSF was well tolerated by subcutaneous route and induced improvement in the neutropenia caused by radiotherapy.

• Journal of Radiation Protection and Research
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• 제34권1호
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• pp.25-30
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• 2009

Micro-columnar CsI(Tl) is the most popular scintillator material which is used for many indirect digital X-ray imaging detectors. The light scattering at the surface of micro-columnar CsI(Tl) scintillator was studied to find the correlation between the surface roughness and the resultant image resolution of indirect X-ray imaging detectors. Using a commercially available optical simulation program, Light Tools, MTF (Modulation Transfer Function) curves of the CsI(Tl) film thermally evaporated on glass substrate with different thickness were calculated and compared with the experimental estimation of MTF values by the edge X-ray image method and CCD camera. It was found that the standard deviation value of Gaussian scattering model which is determined by the surface roughness of micro-columns could certainly change the MTF value of image sensors. This model and calculation methodology will be beneficial to estimate the overall performance of indirect X-ray imaging system with CsI(Tl) scintillator film for optimum design depending on its application.

• 대한방사선기술학회지:방사선기술과학
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• 제42권2호
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• pp.105-111
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• 2019

A medical personnel could be placed beside a patient together in CT room to do Ambu-bag for a seriously ill patients or emergency patient. At this time, the medical personnel can be exposed indirect radiation unnecessarily. In this case, it is necessary to recognize indirect radiation dose levels and methods to reduce them using actual clinical CT protocols such as Chest, Abdomen, and Brain CT. We researched surface radiation dose with or without radiation protectors such as apron and goggles according to different distances far from gantry using two different CT scanners (Fixed MDCT and mobile CT). As a result, for Chest, Abdomen, and Brain CT with Fixed MDCT, indirect radiation dose on thorax portion were 0.047, 0.089, 0.034 mSv without apron. Also, those with apron were 0.007, 0.012, 0.006 mSv. In case of mobile CT, it was 0.014 mSv without apron and 0.005 mSv with apron. By using protectors and increasing the distance, we could reduce it to 97%. Systematic management is necessary based on the measured data in order to minimize radiation damage due to indirect exposure dose.

• Journal of Radiation Protection and Research
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• 제38권2호
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• pp.52-59
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• 2013

전베타 방사능 분석법을 이용한 내부오염 스크리닝법을 검증하였고 실제 의료용 동위원소 생산시설 종사자 내부오염을 판단하는데 적용하였다. 종사자의 작업 종료 후 첫 번째로 채취된 뇨시료(spot 시료)와 24시간 동안 취합된 뇨시료(24 h 시료)를 채취하여 측정하였다. 특정 종사자의 경우를 제외하고 대부분의 측정결과는 일반인 체내 기저준위인 100 Bq $kg^{-1}$을 기준으로 22% 이내로 변동폭이 작았다. 측정결과 작업종료 후 수 시간 이내 종사자 뇨시료의 전베타 농도가 전반적으로 35% 이상 상승하는 경향이 있었다. 또한 스크리닝 결과와 작업일지를 바탕으로 작업장내부 구조상 오염을 유발하는 요인을 추정 할 수 있었으며 추가 세부 핵종별 분석법을 바탕으로 내부피폭선량을 평가해야 할 것으로 판단되었다. 한편 사업장에서 신속히 적용 가능한 내부오염평가 절차를 수립하였다.

• 한국의학물리학회지:의학물리
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• 제21권4호
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• pp.360-366
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• 2010

최근 정밀한 암 치료를 위해 방사선 치료기술이 강도변도 방사선치료, 영상유도 방사선치료 등의 눈부신 발전을 이루어 왔다. 2000년 이후로는 치료실에서 환자의 실제 치료위치를 정확히 파악하여 정밀한 치료를 가능하게 하는 영상 유도방사선 치료기술이 사용되고 있으며 가장 중요한 기술 중 하나가 방사선 치료 전에 다양한 방법의 의료 영상을 이용하여 환자의 치료 위치를 보정하는 것으로 가장 최근의 기술로는 선형가속기에 장착된 2차원 평면검출기를 이용한 콘빔CT (Cone Beam CT: CBCT)가 사용되고 있다. 본 연구에서는 기존의 CBCT의 "half fan" 조건에서 획득된 projection영상을 이용하여 360도 회전한 모든 영상이 아닌 제한된 각도에서 획득한 투사영상을 이용하여 환자의 해부학적 정보를 볼 수 있는 디지털 영상합성영상(Digital Tomosynthesis) 기술을 구현하였고 실제 위치교정을 위해 촬영된 환자 데이터를 이용하여 방사선 치료 환자 위치 교정을 위한 효용성을 검증하였다. 그 결과 동일 단층상에서의 해부학적 정보 표현에서 CBCT 영상과 비교하였을 때 유사성을 보였고 선량적인 측면에서 우월성을 나타냈다. 이러한 DTS의 장점을 극대화 하고 최적화가 이루어진다면 방사선 치료 위치 보정용으로 CBCT를 대체 할 수 있는 기술이 될 수 있을 것이라 기대한다.

• Radiation Oncology Journal
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• 제37권3호
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• pp.215-223
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• 2019

Purpose: To determine prognostic significance of lymphovascular invasion (LVI) in prostate cancer patients who underwent adjuvant or salvage postoperative radiotherapy (PORT) after radical prostatectomy (RP) Materials and Methods: A total of 168 patients with prostate cancer received PORT after RP, with a follow-up of ≥12 months. Biochemical failure after PORT was defined as prostate-specific antigen (PSA) ≥0.2 ng/mL after PORT or initiation of androgen deprivation therapy (ADT) for increasing PSA levels regardless of the value. We analyzed the clinical outcomes including survivals, failure patterns, and prognostic factors affecting the outcomes. Results: In total, 120 patients (71.4%) received salvage PORT after PSA levels were >0.2 ng/mL or owing to clinical failure. The 5-year biochemical failure-free survival (BCFFS), clinical failure-free survival (CFFS), distant metastasis-free survival (DMFS), overall survival, and cause-specific survival rates were 78.3%, 94.3%, 95.0%, 95.8%, and 97.3%, respectively, during a follow-up range of 12-157 months (median: 64 months) after PORT. On multivariate analysis, PSA level of ≤1.0 ng/mL at the time of receiving PORT predicted favorable BCFFS, CFFS, and DMFS. LVI predicted worse CFFS (p = 0.004) and DMFS (p = 0.015). Concurrent and/or adjuvant ADT resulted in favorable prognosis for BCFFS (p < 0.001) and CFFS (p = 0.017). Conclusion: For patients with adverse pathologic findings, PORT should be initiated as early as possible after continence recovery after RP. Even after administering PORT, LVI was an unfavorable predictive factor, and further intensive adjuvant therapy should be considered for these patients.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4871-4875
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• 2013

This meta-analysis was performed to evaluate and compare the outcomes of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for treating gastric cancer. A systematic literature search was carried out using the PubMed database, Web of Knowledge, and the Cochrane Library database to obtain comparative studies assessing the safety and efficiency between RG and LG in May, 2013. Data of interest were analyzed by using of Review Manager version 5.2 software (Cochrane Collaboration). A fixed effects model or random effects model was applied according to heterogeneity. Seven papers reporting results that compared robotic gastrectomy with laparoscopic gastrectomy for gastric cancer were selected for this meta-analysis. Our metaanalysis included 2,235 patients with gastric cancer, of which 1,473 had undergone laparoscopic gastrectomy, and 762 had received robotic gastrectomy. Compared with laparoscopic gastrectomy, robotic gastrectomy was associated with longer operative time but less blood loss. There were no significant difference in terms of hospital stay, total postoperative complication rate, proximal margin, distal margin, numbers of harvested lymph nodes and mortality rate between robotic gastrectomy and laparoscopic gastrectomy. Our meta-analysis showed that robotic gastrectomy is a safe technique for treating gastric cancer that compares favorably with laparoscopic gastrectomy in short term outcomes. However, the long term outcomes between the two techniques need to be further examined.