• Progress in Medical Physics
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• v.4 no.1
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• pp.17-21
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• 1993

근접방사선치료는 방사성동위원소를 종양에 밀착시키거나 또는 종양내에 직접 삽입하여 치료하는 방법으로서 종양에는 일시에 많은 선량을 주는 반면 주위 정상조직에는 선량을 최소화시킬 수 있는 장점이 있다. 따라서 근래에 들어 종양치료에 있어서 외부방사선치료와 병행하여 근접방사선치료를 시행하는 병원이 증가하고 있다. 그러나 근접방사선치료는 방출 방사선의 에너지가 낮고, 대부분 짧은 반감기를 가지며, 소형의, 수 mCi에서 수Ci 정도의 방사능을 가진 방사성동위원소들을 인체에 직접 삽입하는 것으로 정확한 선량 분포를 위해서는 방사성동위원소의 방사능량, 위치, 분포 등의 정확성 확보가 절실히 요구된다. 따라서 이 논문은 근접방사선치료시스템의 QA프로그램 개발을 위하여 작성하였다.

• The Journal of Korean Society for Radiation Therapy
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• v.23 no.1
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• pp.7-12
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• 2011

Purpose: To analyze availability of MR images before and after external beam radiotherapy in brachytherapy, we will acquire MR images before and after external beam radiotherapy and compare the change of direction of uterine cavity and analyze the accuracy of applicator insertion. Materials and Methods: From January 2009 to December 2010, we compared MR images before and after external beam radiotherapy for uterine cervical cancer only with radical purpose treatment. MR images which was acquired after external beam radiotherapy has done with inserted status of CT/MR applicator. Results: As a consequence, the tumor was markedly reduced after external beam radiotherapy. The change of anteflexion of uterus turned into retroflexion of the uterine cavity was 17.1%. The case of wrong insertion of tandem include direction or length was 14.3%. Conclusion: According to MR images taken after external beam radiotherapy, we recognized not only reduced the tumor volume but the marked change of exact direction or length of the uterine cavity. So the confirmation of accurate insertion based on MR images before brachytherapy could be very helpful for optimal brachytherapy treatment planning with reduced applicator insertion errors.

• The Journal of Korean Society for Radiation Therapy
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• v.18 no.2
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• pp.119-125
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• 2006

Purpose: To measure the dose for dose optimization at the reference point (A, B) and the critical organ with multi Purpose brachytherapy phantom (MPBP). For this wort the MPBP was custom made, and designed to reconstruct the treatment applicator using multi function applicator (MFA) in the same way as the treatment of patient. Materials and Methods: Dose measurements were made at the reference points (A, B) and the bladder with thermoluminescence dosimeter (TLD) for four patients with tandem and ovoid of uterine cervix cancer using the phantom. In Phantom, Total 20 times of the measurements were made with 5 times a patient. Results: The results of TLD measurements in MPBP phantom showed the relative error ranging from -3.2% to 3.8% at A point, and -1.4% to 4% at B point and 1.3% to 7.15% at the bladder of reference point. Conclusion: The reproducibility of dose measurement under the same condition as the treatment could be achieved using the custom-made MFA in phantom and the dose at the reference point (A, B) and bladder could be analyzed accurately. The measured dose acquired in MPBP can apply for the dose optimization.

• 대한방사선치료학회:학술대회논문집
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• 1996.06a
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• pp.9-11
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• 1996

• Radiation Oncology Journal
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• v.17 no.3
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• pp.179-187
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• 1999

Brachytherapy has been proved to be an effective method for the purpose of increasing radiation dose to the tumor and reducing the dose to the surrounding normal tissue. In head and neck cancer, the rationale of brachytherapy is as follows; Firstly, early small lesion is radiocurative and the major cause of failure is local recurrence. Seondly, it can diminish evidently the dose to the normal tissue especially masseteric muscle and salivary gland. Thirdly, the anatomy of head and neck is suitable to various technique of brachytherapy. On background of accumulated experience of LDR iridium brachytherapy of head and neck cancer for the last 15 years, the author reviewed the history of radioisotope therapy, the characteristics of radionuclides, and some important things in the method, clinical technique and treatment planning. The author analyzed the clinical result of 185 cases of head and neck cancer treated in the Korea Cancer Center Hospital. Finally the future prospect of brachytherapy of head and neck cancer is discussed.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.57-57
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• 2003

목적 : 미국 NRC 의 위험도 평가 방법론(NUREG/CR-6642)에 국내에서 시행되는 고선량율 근접치료의 표준입력 자료를 대입하여 고선량율 근접치료시 위험도를 정량적으로 산출하고 그 값을 비교하고자 한다. 대상 및 방법 : 고선량율 근접치료 시스템에 대한 위험도 평가를 위해 국내에서 고선량율 근접치료를 시행하고 있는 17개 의료기관으로부터 방사성동위원소의 설치와 폐기시의 방사능, 선원의 유형, 연간 총 치료회수 등 기초 자료를 수집하였다. 이로부터 방사성동위원소의 평균세기 연간 치료회수 등을 미국 NRC의 위험도 평가 방법론의 데이터베이스에 입력하여 고선량율 근접치료의 직무별, 피폭인의 종류, 정상상태와 사고 등의 형태에 따라 그 위험도를 구하였다. 결과 : 국내 고선량율 근접치료의 위험도는 미국 NRC의 위험도 평가 방법론에 따른 데이터베이스의 입력 결과 일반인의 정상상태와 사고 그리고 방사선종사자의 정상상태와 사고 시에 따라 그 위험도가 1.52-01, 2.96-03, 8.64-01, 3.32-02 rem/yr로 산출되었고 그 값을 미국 NRC의 값과 비교하였다. 결론 : 고선량율 근접치료 시 미국 NRC의 위험도 결과보다는 국내의 경우 수배 정도 높게 계산되었고 일반인과 방사선종사자, 정상상태와 사고, 직무별 패턴 등은 동일한 것으로 간주된다.

• Radiation Oncology Journal
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• v.25 no.3
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• pp.177-184
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• 2007

Purpose: To evaluate the palliative effect of endobronchial brachytherapy (EBB) for patients with lung cancer that previously received external beam radiotherapy (EBRT). Materials and Methods: From July 1992 to May 2003, 29 patients with a recurrent or persistent lung cancer were treated with palliative EBB at our institute. EBB consisted of three fractions (once a week) of a dose of 5 Gy using the high dose-rate remote afterloader. Symptomatic improvement was assessed subjectively, and patients were divided into two groups according to whether symptoms were improved or not. Factors such as age, performance status, duration from EBRT to EBB and the location of the tumor were compared between the improved and unimproved groups of patients. Results: Overall symptomatic improvement was found in 27 out of 52 symptoms (52%). Improvement as to the type of symptoms was seen in 41 %, 50%, 82% and 33% of patients with cough, dyspnea, hemoptysis, and obstructive pneumonia respectively. The rate of improvement of hemoptysis was more than that of cough (p<0.05). The median time to symptom relapse was 5 months. The improved patient group (n=17, 59%) had a better performance status and longer duration from EBRT to EBB than the unimproved patient group (p<0.05). Lesions located in the distal trachea and/or main bronchus were found more frequently in the improved group of patients than in the unimproved group of patients, but the difference was not statistically significant (p=0.06). Fatal complications developed in two patients (7%), which were a hemoptysis and bronchopleural fistula respectively. Conclusion: Symptom improvement was found in 60% of patients after EBB and improvement was maintained for 5 months. Palliative EBB, even when EBRT was given previously, can be effective for a patient that has an endobronchial symptom, such as hemoptysis, and for a patient with good performance and a long duration from previous EBRT to EBB.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.228-236
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• 2002

Purpose : Although high-dose-rate (HDR) brachytherapy regimens have been practiced with a variety of modalities and various degrees of success, few studies on the subject have been conducted. The purpose of this study was to compare the results of local control and late complication rate according to different HDR brachytherapy fractionation regimens in uterine cervical cancer patients. Methods and Materials : From November 1992 to March 1998, 224 patients with uterine conical cancer were treated with external beam irradiation and HDR brachytherapy. In external pelvic radiation therapy, the radiation dose was $45\~54\;Gy$ (median dose 54 Gy) with daily fraction size 1.8 Gy, five times per week. In HDR brachytherapy, 122 patients (Group A) were treated with three times weekly with 3 Gy to line-A (isodose line of 2 cm radius from source) and 102 patients (Group B) underwent the HDR brachytherapy twice weekly with 4 or 4.5 Gy to line-A after external beam irradiation. Iridium-192 was used as the source of HDR brachytherapy. Late complication was assessed from grade 1 to 5 using the RTOG morbidity grading system. Results : The local control rate (LCR) at 5 years was $80\%$ in group A and $84\%$ in group B (p=0.4523). In the patients treated with radiation therapy alone, LCR at 5 years was $60.9\%$ in group A and $76.9\%$ in group B (p=0.2557). In post-operative radiation therapy patients, LCR at 5 years was $92.6\%$ In group A and $91.6\%$ in group B (p=0.8867). The incidence of late complication was $18\%$ (22 patients) and $29.4\%$ (30 patients), of bladder complication was $9.8\%$ (12 patients) and $14.7\%$ (15 patients), and of rectal complication was $9.8\%$ (12 patients) and $21.6\%$ (22 patients), in group A and B, respectively. Lower fraction sized HDR brachytherapy was associated with decrease in late complication (p=0.0405) (rectal complication, p=0.0147; bladder complication, p=0.115). The same result was observed in postoperative radiation therapy patients (p=0.0860) and radiation only treated patients (0=0.0370). Conclusion : For radiation only treated patients, a greater number of itemized studies on the proper fraction size of HDR brachytherapy, with consideration for stages and prognostic factors, are required. In postoperative radiation therapy, the fraction size of HDR brachytherapy did not have much effect on local control, yet the incidence of late complication increased with the elevation in fraction size. We suggest that HDR brachytherapy three times weekly with 3 Gy could be an alternative method of therapy.

• Journal of radiological science and technology
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• v.33 no.3
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• pp.283-288
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• 2010

In order to evaluate radiation dose on the uterus and surrounding organs during brachytherapy for cervical cancer, of which the frequency of occurrence is high in Korean women, as well as radiation dose on medical staffs in proximity of patients receiving the therapy, a mathematical phantom based on reference Korean was established and the radiation dose was calculated accordingly. For simulation, $^{192}Ir$, which is useful in brachytherapy, was selected as radionuclide. Also, it was presumed that the intensity of initial radiation was 1 Ci. The result indicated the radiation of 4.92E-14 Gy/Ci in the uterus, the source organ. In addition, radiation on people around patient receiving the therapy was found to be 1.24E-07 Sv at a distance of 30 cm.

• 대한방사선방어학회:학술대회논문집
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• 2009.04a
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• pp.264-265
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• 2009