• Progress in Medical Physics
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• v.21 no.2
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• pp.223-231
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• 2010

We have taken surveys about total 72 departments of radiation oncology which is performing the treatment with linear accelerator and brachytherapy unit in Korea. The survey was included the research about the linear accelerator, brachytherapy, Also, we surveyed the various performance (QA period, manpower, time) of quality control for understanding of efficiency. The survey results show that the QA test of daily and weekly are almost same comparing to USA and Europe but the QA performance of monthly and yearly in Korea are 15.5 which is less than USA and Europe recommended QA item number of 17 to 21. The manpower and QA time in Korea also lower than 50% of USA and Europe recommended because the manpower and QA time limitation in Korea. It will be expected that the manual of quality management in each clinic could be appropriately established when combining the present results with previously published AAPM TG-40 and other protocols.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.68-76
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• 1998

Background: Patients with centrally recurred bronchogenic carcinoma make a complaint of many symptoms like hemoptysis, cough & dyspnea. At these conditions, the goal of treatment is only to relieve their symptoms. High dose rate brachytherapy(HDR-BT) is the palliative treatment modality of centrally located endobronchial tumor regardless of previous external irradiation(XRT) on the same site in symptomatic patients. Methods: We studied the effects of HDR-BT in 26 patients with symptomatic recurrent lung cancer. Patients(male: 24, mean age: 54yrs)were treated with HDR-BT underwent bronchoscopic placement of $^{192}Ir$ HDR after loading unit(Gammamed$^{(T)}$, Germany) to deliver 500cGY intraluminal irradiation at a depth of 1cm every lwk on 3 occasions. Evaluation at base line and 4wks after HDR brachytherapy included chest X-ray, bronchscopy, symptoms (Standadized Scale for dyspnea,cough,hemoptysis), and Karnofsky performance scale. Results: Endobronchial obstruction was improved in 11/26 patients(37%). Atelectasis in chest X-ray was improved in 5/15 patients(33%). Hemoptysis, dyspnea & cough were improved in 5/10 patients (50%), 5/8 patients (62%) & 10/18 patients (56%) respectively. Karnofsky performance status was changed from 76.4 scores in pretreatment to 77.6 scores after treatment. During HDR-BT, massive hemoptysis (2 patients) and pneumothorax(1 patient) were occurred as complications. Conclusion: We concluded that HDR-BT gave additional benefits for the control of symptoms and general performance and endobronchial obstruction & atelectasis. And HDR-BT will be an additional treatment for the recurrent and endobronchial obstructive lung cancer.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.45-52
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• 1995

This study is to compare A point doses in human pelvic phantom by film dosimetry, computer planning and manual calculation by using of along-away table. We developed tissue equivalent human pelvic phantom composed of four pieces of cylindrical acryl tubes with water, to simulate intracavitary radiation (ICR) in patients with cervix cancer. When the phantom assembled from 4 pieces, it has a small space for inserting Fletcher-Suit-Delclos applicator like a human vagina. Fletcher-Suit-Delclos applicator inserted into the space was packed tightly with furacin gauzes, and three $^{137}Cs$ sources with radioactivity of $15.7mg\;Ra-eq$ were inserted into the tandem. For the film dosimetry, two pieces of X-OMAT V film (Kodak Co.) of which planes include point A, were arranged orthogonally in the slits between phantoms. A point dose and iso-dose curves were measured by means of optical densitometer. A point doses by film dosimetry, RTP system and manual calculation by using of along-away table were compared, and iso-dose curves by film dosimetry and computer planning were also compared. The dose of A point was 51.2cGy/hr by film dosimetry, 46.7cGy/hr by RTP system and 47.9 cGy/hr by along-away table. A point dose by computer planning was similar to the dose by calculation using of along-away table with acceptable accuracy $({\pm}3%)$, however, the dose by film dosimetry was different from two others with about 10% error. Since most clinical beams contains a scatter component of low energy photons, the correlation between optical density and dose becomes tenuous. In addition, film suffers from several potential errors such as changes in processing conditions, interfilm emulsion differences, and artifacts caused by air pockets adjacent to the film. For these reasons, absolute dosimetry with film is impractical, however, it is very useful for checking qualitative patterns of a radiation distribution. In future, solid state dosimeter such as TLD must be used for the dosimetry of ionizing radiation. When considerable care is used, precision of approximately 3% may be obtained using TLD.

• Progress in Medical Physics
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• v.15 no.2
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• pp.94-99
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• 2004

Radiochromic film has several advantages; high spatial resolution, relatively low spectral sensitivity, near tissue equivalence and requires no special development procedure. The object of this study was to measure the anisotropy of an Ir-192 source (microSelectron manufactured by Nucletron) in a few mm regions from the source, using the GafChromic film. The GafChromic film was calibrated in the range of 0∼105 Gy, using a 4 MV photon beam, and the anisotropy function measured in an acrylic phantom using the GafChroimic film. The data obtained gave agreement to within 4.4% of the Monte Calro calculation, by J. F. Williamson, at a radial distance of 2.5 mm with polar angles of 50 to 130$^{\circ}$, while a maximum deviation of 17.6% was observed at angles near 140$^{\circ}$and agreement within 3.7% at a radial distance of 5 mm at polar angles between 35 to 150$^{\circ}$ and a maximum deviation of 7.6% was observed at angles near 30$^{\circ}$. A GafChromic film can be used as a more efficient detector for measuring the anisotropy of an HDR $^{192}$ Ir source at close distances than any other detector.

• Radiation Oncology Journal
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• v.29 no.2
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• pp.71-82
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• 2011

Purpose: To evaluate the biochemical control rate and the rate of side effects after performing permanent brachytherapy of localized prostate cancer. Materials and Methods: 67 patients with localized prostate cancer were treated with brachytherapy between April 2007 and December 2008. Of these, 43 patients who were followed up and did not receive external radiotherapy were evaluated for the change in prostate specific antigen (PSA) level and the occurrence of side effects. In total, 18 patients were classified as low risk, 19 patients as intermediate risk, and 6 patients as high risk. The prescription dose was 145 Gy. Results: A PSA increase greater than 2 ng/mL occurred in 2 patients (4.7%). Radiation Therapy Oncology Group (RTOG) grade 1 and 2 acute urologic complications (UC) occurred in 40 and 3 patients, respectively. Further, 5 patients had RTOG grade 1 acute rectal complication (RC). The numbers of RTOG grade 1, 2, and 3 chronic UC were 1, 4, and 1, respectively. The numbers of RTOG grade 1, 2, and 4 chronic RC were 5, 10, and 3, respectively. The statistically significant risk factors (RF) of acute RC were the minimal dose in the most irradiated 0.1 cc volume ($D_{0.1cc}$, p=0.041) and absolute volume receiving 150% of the prescribed dose ($V_{150cc}$, p=0.038) in the entire rectum (ER). The percentage ($V_{100%}$, p=0.019) and absolute volume ($V_{100cc}$, p=0.047) in the involved rectum (IR) were also statistically significant. The RF of chronic RC were $V_{100%}$ (p=0.011) in the ER and the $D_{0.1cc}$ (p=0.049), $V_{100cc}$ (p=0.023) in the IR. The number of used seeds were related with acute UC (p=0.028). Conclusion: Permanent brachytherpy of localized prostate cancer showed a favorable short term biochemical control rate. As such, selective intermediate and high risk patients can be managed with permanent brachytherapy. The effort to reduce rectal complication is also necessary.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.43-51
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• 1999

Purpose : To discuss the technical aspect of interstitial brachytherapy including method of implant, insertion time of radioactive source, total radiation dose, and complication, we reviewed patients who had diagnoses of soft tissue sarcoma and were treated by conservative surgery, interstitial implant and external beam radiation therapy Materials and Methods : Between May 1995 and Dec. 1997, ten patients with primary or recurrent soft tissue sarcoma underwent surgical resection (wide margin excision) and received radiotherapy including interstitial brachytherapy. Catheters were placed with regular intervals of 1 ~l.5 cm immediately after tumor removal and covering the critical structures, such as neurovascular bundle or bone, with gelform, muscle, or tissue expander in the cases where the tumors were close to those structures. Brachytherapy consisted of high dose rate, iridium-192 implant which delivered 12~15 Gy to 1 cm distance from the center of source axis with 2~2.5 Gy/fraction, twice a day, starting on 6th day after the surgery, Within one month after the surgery, total dose of 50~55 Gy was delivered to the tumor bed with wide margin by the external beam radiotherapy. Results : All patients completed planned interstitial brachytherapy without acute side effects directly related with catheter implantation such as infection or bleeding. With median follow up duration of 25 months (range 12~41 months), no local recurrences were observed. And there was no severe form of chronic complication (RTOGIEORTC grade 3 or 4). Conclusion : The high dose rate interstitial brachytherapy is easy and safe way to minimize the radiation dose delivered to the adjacent normal tissue and to decrease radiation induced chronic morbidity such as fibrosis by reducing the total dose of external radiotherapy in the management of soft tissue sarcoma with conservative surgery.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.253-263
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• 1991

Twenty-seven patients with unresectable extrahepatic bile duct carcinoma (n=21) or with microscopic evidence of tumor rest after aggressive surgery for extrahepatic bile duct carcinoma (n=6) between 1985 and 1990 were given radiotherapy consisting intentionally external radiotherapy and/or intraluminal therapy using Gamma-Med 12i (192-Ir) high dose rate (HDR) remote control afterloading system following bile drainage procedures and Gianturco stent insertion. The objectives of this study has been to assess the feasibility and effects on survival of a combination of external radiotherapy and brachytherapy with which we hope to achieve optimal loco-regional control for patients with unresectable extrahepatic bile duct tumors. Sixteen patients were men and eleven were women, and the mean age was 58 years (34-70). 10MV X-ray was used for radiation therapy, with the total dose ranging from 45 Gy to 55 Gy, and intraluminal brachytherapy performed after external radiotherapy, with the dose of total 15 Gy. The minimum follow up was 12 months. Failure were predominantly local-regional, without distant failure. Median survival was 10 months; 2-year actuarial survival rates was $21\%$. Median survival for common hepatic duct (CHD) cancer was 9 months; for common bile duct (CBD) cancer, was 16 months. And median survival for incomplete surgery/external radiotherapy group and external/intraluminal radiotherapy group was 10 months; for external radiotherapy alone group, was 6 months. Use of chemotherapy and/or hyperthermia were not affected in survival. Therefore, our result is that the survival rates in the group of external/intraluminal radiotherapy were comparable with ones in the group of incomplete resection/external radiotherapy, and so we believe that the aggressive local and regional radiotherapy can improve the quality of life and the survival length.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1239-1240
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• 2015

본 논문은 구강내 장치를 이용한 악정형 치료에 있어 환자가 장치를 장착하는 시간과 적용되는 응력과 변형률을 측정하여 치료결과의 완성도를 높이는 데에 있어, 근접무선통신 장치인 NFC(Near Field Communication)를 매개로하여 구강내외 장치의 상태를 모니터링하는 방안에 대한 고찰을 중점적으로 수행하였다. 구강내외에 상태를 계측하기 위한 센서를 설치하고 근접무선통신을 이용하여 병원에서 내원한 환자 상태의 모니터링을 구현하는 시스템을 설계하였으며 무선전력송신 시험을 수행하여 설계변수에 대한 민감도를 살펴보았다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.373-378
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• 1997

시험가동중인 다목적연구용 '하나로'를 이용하여 근접치료용으로 사용되는 $^{192}$ IR seed 제조실험을 하였다. '하나로'의 특성을 고려하여 제작된 조사표적용기에 표적용 Ir seed를 넣고 밀봉한 후 He 누출시험을 통과한 표적만 원자로의 HTS 조사공에서 중성자 조사시켰다. HTS 조사공의 평균 열중성자속은 측정결과 원자로출력 15 MWt일 때 2.54 $\times$ $10^{13}$ n/$\textrm{cm}^2$.sec였다. 5회에 걸쳐 5개의 조사표적을 사용하여 총 200개의 $^{192}$ Ir seed를 제조, 실험하였으며 2시간 조사후 14일간 냉각시킨 Ir seed의 r-ray spectrum을 분석한 결과 $^{l92}$Ir외의 불순핵종은 검출되지 않았다. Ir seed의 방사능은 이온전리함을 사용하여 측정하였으며 방사능 측정결과 개별 $^{192}$ Ir seed의 방사능값은 평균 방사능값으로부터 $\pm$5 % 이내오차의 방사능 균일도를 갖는 것이 확인되었다.차의 방사능 균일도를 갖는 것이 확인되었다.

• Nuclear industry
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• v.15 no.10 s.152
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• pp.73-78
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• 1995

이리듐-192(lr-192)는 각종 형태의 암조직의 특성에 맞게 변형하여 적절히 사용되는 특수치료용 동위원소로서, 반감기가 74일로 짧으며 에너지도 낮아 보관$\cdot$관리가 용이하고, 금속 철선 형태로 제작되어 인체내의 암조직에 바늘상태로 자입하는데 편리하게 사용되므로 근접치료에 가장 보편적으로 사용된다. 또한 라듐(Ra-226)이나 세슘(Cs-137)과 달리 시술하는 의료진의 방사선피폭에 전혀 문제가 없다. 원자력병원 연구팀은 최근 이를 이용, 안구 적출없이 안구암흑색종을 치료하는 신기술을 개발한 바 있다.