• 한국의학물리학회지:의학물리
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• 제32권2호
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• pp.25-39
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• 2021

Brachytherapy, along with external beam radiation therapy (EBRT), is an essential and effective radiation treatment process. In brachytherapy, in contrast to EBRT, the radiation source is radioisotopes. Because these isotopes can be positioned inside or near the tumor, it is possible to protect other organs around the tumor while delivering an extremely high-dose of treatment to the tumor. Brachytherapy has a long history of more than 100 years. In the early 1900s, the radioisotopes used for brachytherapy were only radium or radon isotopes extracted from nature. Over time, however, various radioisotopes have been artificially produced. As radioisotopes have high radioactivity and miniature size, the application of brachytherapy has expanded to high-dose-rate brachytherapy. Recently, advanced treatment techniques used in EBRT, such as image guidance and intensity modulation techniques, have been applied to brachytherapy. Three-dimensional images, such as ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography are used for accurate delineation of treatment targets and normal organs. Intensity-modulated brachytherapy is anticipated to be performed in the near future, and it is anticipated that the treatment outcomes of applicable cancers will be greatly improved by this treatment's excellent dose delivery characteristics.

• Radiation Oncology Journal
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• 제17권3호
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• pp.179-187
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• 1999

치료선량의 증가와 주위 정상조직의 보호의 의미에서 근접치료의 효과는 입증되어 있다. 그러나 우리 나라에서는 아직 통상치료법으로 상용화가 되어 있지 않다. 저자는 저선량률 이리디움 근접조사치료의 임상적 경험을 바탕으로 두경부암에서의 근접조사치료의 역사, 사용되는 동위원소의 재원 및 특성, 시행 시 고려 하여야할 사항, 임상기술적인 문제, 방사선물리학적 문제 등을 검토하였고 저자의 임상 경험 185례의 치료성적을 분석하여 그 효과를 검증하였고 마지막으로 향후 발전방향을 제시하여 보았다.

• Radiation Oncology Journal
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• 제16권4호
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• pp.357-366
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• 1998

Brachytherapy is an essential part of radiotherapy for uterine cervical cancer. The low dose rate (LDR) regimen has been the major technique of intracavitary therapy for cervical cancer. However, there has been an expansion in the last 20 years of high dose rate (HDR) machines using Ir-192 sources. Since 1979, HDR brachytherapy has been used for the treatment of uterine cervical cancer in Korea. The number of institutions employing HDR has been increasing, while the number of low dose rate system has been constant. In 1995, there was a total 27 HDR brachytherapy units installed and 1258 cases of patients with cervical cancer were treated with HDR Most common regimens of HDR brachytherapy are total dose of 30-39 Gy at point A with 10-13 fractions in three fractions per week. 24-32 Gy with 6-8 fractions in two fractions per week, and 30-35 Gy with 6-7 fractions in two fractions per week. The average fractionation regimen of HDR brachytherapy is about 8 fractions of 4.1 Gy each to Point A. In Korea, treatment results for HDR brachytherapy are comparable with the LDR series and appears to be a safe and effective alternative to LDR therapy for the treatment of cervical carcinoma. Studies from the major centers report the five-year survival rate of cervical cancer as. 78-86$\%$ for Stage 1, 68-85$\%$ for stage 11, and 38-56$\%$ for Stage III. World-wide questionnaire study and Japanese questionnaire survey of multiple institutions showed no survival difference in any stages and dose-rate effect ratio (HDR/LDR) was calculated to be 0.54 to 0.58. However the optimum treatment doses and fractionation schemes appropriate to generate clinical results comparable to conventional LDR schemes have yet to be standardized. In conclusion, HDR intracavitary radiotherapy is increasingly practiced in Korea and an effective treatment modality for cervical cancer. To determine the optimum radiotherapy dose and fractionation schedule, a nation-wide prospective study is necessary in Korea. In addition, standardization of HDR application (clinical, computer algorithms, and dosimetric aspects) is necessary.

• Nuclear Medicine and Molecular Imaging
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• 제40권2호
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• pp.113-119
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• 2006

Coronary artery disease is a loading cause of morbidity and mortality across the world. Percutaneous coronary intervention has become the major technique of revascularization. However, restenosis remains a major limitation of this procedure. Recently the need for repeat intervention due to restenosis, the most vexing long-term failure of percutaneous coronary intervention, has been significantly reduced owing to the introduction of two major advances, intracoronary brachytherapy and the drug-eluting stents. Intracoronary brachytherapy has been employed in recent years to prevent restenosis lesions with effective results, principally in in-stent restenosis. Restenosis is generally considered as au excessive form of normal wound healing divided up in precesses: elastic recoil, neointimal hyperplasia, and negative vascular remodeling. Restenosis has previously been regarded as a proliferative process in which neointimal thickening, mediated by a cascade of inflammatory mediators and other factors, is the key factor. Ionizing radiation has been shown to decrease the proliferative response to injury in animal models of restenosis. Subsequently, several randomized, double blind trials have demonstrated that intracoronary brachytherapy can reduce the rates of both angiographic restenosis and clinical event rates in patients undergoing percutaneous coronary intervention for in stent restenosis. Some problems, such as late thrombosis and edge restenosis, have been identified as limiting factors of this technique. Brachytherapy is a promising method of preventing and treating coronary artery restenosis.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.7167-7170
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• 2015

Background: Although 3D image based brachytherapy is currently the standard of treatment in cervical cancer, most of the centres in developing countries still practice orthogonal intracavitary brachytherapy due to financial constraints. The quest for optimum dose and fractionation schedule in high dose rate (HDR) intracavitary brachytherapy (ICBT) is still ongoing. While the American Brachytherapy Society recommends four to eight fractions of each less than 7.5 Gy, there are some studies demonstrating similar efficacy and comparable toxicity with higher doses per fraction. Objective: To assess the treatment efficacy and late complications of HDR ICBT with 9 Gy per fraction in two fractions. Materials and Methods: This is a prospective institutional study in Southern India carried on from $1^{st}$ June 2012 to $31^{st}$ July 2014. In this period, 76 patients of cervical cancer satisfying our inclusion criteria were treated with concurrent chemo-radiation following ICBT with 9 Gy per fraction in two fractions, five to seven days apart. Results: The median follow-up period in the study was 24 months (range 10.6 - 31.2 months). The 2 year actuarial local control rate, disease-free survival and overall survival were 88.1%, 84.2% and 81.8% respectively. Although 38.2% patients suffered from late toxicity, only 3 patients had grade III late toxicity. Conclusions: In our experience, HDR brachytherapy with 9 Gy per fraction in two fractions is an effective dose fractionation for the treatment of cervical cancer with acceptable toxicity.

• Asian Pacific Journal of Cancer Prevention
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• 제17권12호
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• pp.5281-5285
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• 2016

Background: Brachytherapy is the most commonly used conservative treatment for the uveal melanoma. The aim of this study was to evaluate therapeutic results of Ruthenium-106 plaque brachytherapy in the management of localized uveal melanoma cases. Methods: We reviewed retrospectively the clinical records of all patients treated in our department for an uveal melanoma, undergoing Ruthenium-106 plaque brachytherapy, from January 1996 to December 2015. We focused on clinical features, therapeutic characteristics, local and distant tumor control and side effects. Results: Nineteen patients were enrolled in our study. Mean age was 56.2 years (28-79) and the sex ratio was 1.37:1 males to females. Diagnosis was made on the basis of ophthalmological clinical examination, angiography, ultrasound and/or magnetic resonance. Median tumor diameter was 9.7 mm (6-13) and median thickness 4.4 mm (2.5-8). The dose of Ruthenium-106 plaque brachytherapy prescribed to the apex of each tumor was 70 Gy in all cases. The median radiation dose to the sclera surface was 226.4 Gy (range: 179.6-342.3) and the median total application time 115.2 hours (range: 27 to 237). After a median follow-up of 61.5 months, local control was achieved in 17 patients (89%): 16 demonstrated a partial tumor response and 1 tumor stabilization. Two patients suffered local progression leading to enucleation, one dying of hepatic metastasis. Radiation-induced complications were cataracts in 3 cases and vitreal hemorrhage in 2. Conclusion: Ruthenium-106 plaque brachytherapy is an efficient treatment for localized uveal melanoma, offering good local control with low toxicity.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권5호
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• pp.470-476
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• 2006

Low-dose rate brachytherapy(LDR) has been effective modality for treatment of oral cancer. But the disadvantage of LDR is radioexposure of medical staff. To overcome this problem, high dose rate(HDR) brachytherapy has been developed. Our study evaluates the outcomes of patients with tongue cancer as treated by HDR brachytherapy. Between 2002 and 2005, eight patients with carcinoma of the tongue were treated with HDR brachytherapy. Five patients had AJCC stage I or II disease and the remaining three patients had AJCC stage III or IV. The male-to-female ratio was 2:6 and the mean age was 60.1 years (range: 21-80 years).The median follow-up time was 23.8 months (range: 7-55 months). There was no local failure until now. Three patients showed some complications. Two patients showed soft tissue necrosis. There was no bone sequela in all cases. Our experience in treating tongue cancer with HDR brachytherapy is encouraging, because it gave a satisfactory local control. Prospective studies are necessary to delineate the optimum indication for this treatment modality and long-term outcome.

• Nuclear Engineering and Technology
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• 제45권5호
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• pp.695-700
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• 2013

Thirty-eight radiation safety reports for brachytherapy equipment were evaluated to determine the current status of brachytherapy units in Korea and to assess how radiation oncology departments in Korea complete radiation safety reports. The following data was collected: radiation safety report publication year, brachytherapy unit manufacturer, type and activity of the source that was used, affiliation of the drafter, exposure rate constant, the treatment time used to calculate workload and the HVL values used to calculate shielding design goal values. A significant number of the reports (47.4%) included the personal information of the drafter. The treatment time estimates varied widely from 12 to 2,400 min/week. There was acceptable variation in the exposure rate constant values (ranging between 0.469 and 0.592 ($R{\cdot}m^2/Ci{\cdot}hr$), as well as in the HVLs of concrete, steel and lead for Iridium-192 sources that were used to calculate shielding design goal values. There is a need for standard guidelines for completing radiation safety reports that realistically reflect the current clinical situation of radiation oncology departments in Korea. The present study may be useful for formulating these guidelines.

• 대한방사선치료학회지
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• 제10권1호
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• pp.30-44
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• 1998

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.

• Radiation Oncology Journal
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• 제6권2호
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• pp.277-281
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• 1988

Although widely used in external beam treatment planning, computed tomography scans are infrequent in incranial tumors by implanting of Radioactive isotope. This incranial brachytherapy has only become possible by using CT scans and stereotaxic operation methods. The coincidence of single source and tumor axes in brachytherapy is very important to determine the therapeutic dosages. Eventhough using the CT scan, according to spatial location of tumor tying, the section of tumor will be seen enlargement, cause the tumor will be cut off with slight angle to its axes. Correct analysis of tumor size from source is required for rotated axes in analytical geometry.