• Title/Summary/Keyword: Brachytherapy

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High Dose Rate Cobalt-60 After Loading Intracavitary Therapy of the Uterine Cervical Carcinoma in Srinagarind Hospital, Analysis of Residual Disease

  • Pesee, Montien;Krusun, Srichai;Padoongcharoen, Prawat
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4835-4837
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    • 2012
  • Objectives: To evaluate residual disease in uterine cervical cancer patients treated with teletherapy using combined high dose rate Cobalt-60 brachytherapy. Materials and Methods: A retrospective study of uterine cervical cancer patients, FIGO stages IB-IVB (International Federation of Gynecologists and Obstetricians recommendations), treated by radiotherapy alone between April 1986 and December 1988 was conducted and the outcomes analysed. The patients were treated using teletherapy 50 Gy/25 fractions, five fractions per week to the whole pelvis together with HDR Cobalt -60 afterloading brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions. Results: The study covered 141 patients with uterine cervical cancer. The mean age was 50.0 years with a range of 30-78 years. The mean tumor size was 4.1 cm in diameter (range 1-8 cm). Mean follow - up time was 2.94 years (range 1 month-6.92 years). The overall incidence of residual locoregional disease was 3.5%. Residual disease, according to stage IIB, IIIB and IVA was present in 2.78%, 3.37% and 50.0%. It was noted that there was no evidence of residual disease in stage IB and IIA cases. Conclusion: Combined teletherapy along with high dose rate Cobalt -60 brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions resulted in overall 3.5% residual disease and a 96.5% complete response. The proposed recommendation for improving outcome is initiation of measurements for early detection of disease.

Radiation Dose Calculation in the Surrounding Organs during Brachytherapy of Prostate Cancer (전립선암 근접시료시 주변 장기 선량 평가)

  • Kim, Jung-Hoon;Lim, Chang-Seon;Whang, Joo-Ho
    • Progress in Medical Physics
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    • v.19 no.3
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    • pp.172-177
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    • 2008
  • As a part of estimating quantitative radiation treatment doses, we produced a mathematical phantom based on the standard Korean male. Then, with the prostate as the source organ, we calculated the absorbed dose in the prostate and surrounding organs forecasted to occur during brachytherapy for prostate cancer. To simulate the procedure, we selected $^{25}I$ and $^{103}Pd$ useful in brachytherapy of the prostate as the radionucleids and made an assumption that 1 Ci of initial radioactivity is administered. As a result, we found that the prostate, as the source organ, indicated 101 Gy/Ci and 7.24 Gy/Ci, respectively, in case of $^{125}I$ and $^{103}Pd$. With the exception of the prostate, organs with high absorbed doses were found to be in the order of the penis and scrotum, sigmoid colon, testicles and the urinary bladder, which are relatively close to the prostate.

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Evaluation of Dosimetric Effect and Treatment Time by Plan Parameters for Endobronchial Brachytherapy

  • Choi, Chang Heon;Park, Jong Min;Park, So-Yeon;Kang, SungHee;Cho, Jin Dong;Kim, Jung-in
    • Progress in Medical Physics
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    • v.28 no.2
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    • pp.39-44
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    • 2017
  • This study aims to analyze dose distribution and treatment time of endobronchial brachytherapy (EBBT) by changing the position step size of the dwell position. A solid water phantom and an intraluminal catheter were used in the treatment plan. The treatment plans were generated for 3, 5, 7, and 10 cm treatment lengths, respectively. For each treatment length, the source position step sizes were set as 2.5, 5, and 10 mm. Three reference points were set 1 cm away from the central axis of the catheter, along the axis, for uniform dose distribution. Volumetric dose distribution was calculated to evaluate the dosimetric effect. The total radiation delivery time and total dwell time were estimated for treatment efficiency, which were increased with position step sizes. At half-life time, the differences between the position step sizes in the total radiation delivery time were 18.1, 15.4, 18.0, and 24.0 s for 3, 5, 7, and 10 cm treatment lengths, respectively. The dose distributions were more homogenous by increasing the position step sizes. The dose difference of the reference point was less than 10%. In brachytherapy, this difference can be negligible. For EBBT, the treatment time is the key factor while considering the patient status. To reduce the total treatment time, EBBT can be performed with 2.5 mm position step size.

Image Guided Brachytherapy in Cervix Cancer

  • Park, Sung-Yong;Shin, Kyung-Hwan;Park, Dahl;Cho, Jung-Keun;Kim, Dae-Yong;Kim, Jong-Won;Cho, Kwan-Ho;Kim, Tae-Hyun;Chie, Eui-Kyu
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2002.09a
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    • pp.154-156
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    • 2002
  • Brachytherapy has a long history in the treatment of cancer. However, the treatment planning technique for brachytherapy has lagged somewhat behind the corresponding developments for external beam therapy as far as the imaging technique is concerned. Currently, the orthogonal-film-based treatment planning is performed at most institutions even though the CT-based planning is available. The aim of this study is to evaluate the CT-based vs. the orthogonal-film-based treatment planning in cervix cancer. The doses to point A, point B, rectum and bladder points according to ICRU 38 were calculated for the two methods above. In addition, the volumetric studies such as 3D dose computation and DVH were obtained for the CT-based planning. For the bulky tumor, the isodose lines of point A prescription were not fairly covered for the CTV. The CT -based dose planning can overestimate the maximum dose delivered to bladder and rectum by 30%. The CT-based planning has several advantages over the orthogonal-film-based such as 3D dose display, DVH, and more accurate target delineation. It is suggested that the prescription point in cervix cancer be revised especially for the bulky tumor.

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Assessment of Radiation Dose for Surrounding Organs and Persons Approaching Patients upon Brachytherapy of Cervical Cancer with $^{192}Ir$ ($^{192}Ir$를 사용한 자궁경부암 치료시 주변 장기 및 근접한 사람의 선량 평가)

  • Kang, Se-Sik
    • 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.

Feasibility Study of Source Position Verification in HDR Brachytherapy Using Scintillating Fiber

  • Moon, Sun Young;Jeong, EunHee;Lim, Young Kyung;Chung, Weon Kyu;Huh, Hyun Do;Kim, Dong Wook;Yoon, Myonggeun
    • Progress in Medical Physics
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    • v.27 no.4
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    • pp.213-219
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    • 2016
  • The position verification of the radiation source utilized in brachytherapy forms a critical factor in determining the therapeutic efficiency. Currently, films are used to verify the source position; however, this method is encumbered by the lengthy time interval required from film scanning to analysis, which makes real-time position verification difficult. In general, the source position accuracy is usually tested in a monthly quality assurance check. In this context, this study investigates the feasibility of the real-time position verification of the radiation source in high dose rate (HDR) brachytherapy with the use of scintillating fibers. To this end, we construct a system consisting of scintillating fibers and a silicon photomultiplier (SiPM), optimize the dosimetric software setup and radiation system characteristics to obtain maximum measurement accuracy, and determine the relative ratio of the measured signals dependent upon the position of the scintillating fiber. According to the dosimetric results based on a treatment plan, in which the dwell time is set at 30 and 60 s at two dwell positions, the number of signals is 31.5 and 83, respectively. In other words, the signal rate roughly doubles in proportion to the dwell time. The source position can also be confirmed at the same time. With further improvements in the spatial resolution and scintillating fiber array, the source position can be verified in real-time in clinical settings with the use of a scintillating fiber-based system.

Evaluation of Absorbed Dose According to the Nanoparticle in Prostate Cancer Brachytherapy (전립선암의 근접치료 시 나노입자에 따른 흡수선량평가)

  • Park, Eun-tae;Lee, Deuk-hee;Im, In-chul
    • Journal of the Korean Society of Radiology
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    • v.12 no.2
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    • pp.167-172
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    • 2018
  • This study evaluated absorbed dose of brachytherapy according to the nanoparticle in prostate cancer which many occurred in Korean man and provided basic data. Absorbed dose evaluation was using MCNPX program which was applied Monte Carlo simulation. Source was applied $^{192}Ir$ which was many using in Korean HDR machine and gold, ferric oxide, gadolinium and iodine nanoparticle were applied. Prostate absorbed dose result was increased when using nanoparticle, in particular gold nanoparticle was the highest result as $3.13E-03J/kg{\cdot}e$. Absorbed dose of surrounding organs and distance was similar between using nanoparticle and non-using nanoparticle. Therefore, brachytherapy was used nanoparticle was increased therapeutic ratio and efficiency of radiation therapy.

Measurements of relative depth dose rates for a brachytherapy Ir-192 sourceusing an organic scintillator fiber-optic radiation sensor (유기 섬광체-광섬유 방사선 센서를 이용한 근접 방사선원 Ir-192의 상대 깊이 선량율 측정)

  • Shin, Sang-Hun;Jang, Kyoung-Won;Cho, Dong-Hyun;Yoo, Wook-Jae;Seo, Jeong-Ki;Lee, Bong-Soo;Moon, Joo-Hyun;Kim, Sin;Park, Byung-Gi
    • Journal of Sensor Science and Technology
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    • v.17 no.6
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    • pp.462-469
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    • 2008
  • In this study, we have fabricated a fiber-optic radiation sensor using an organic scintillator and plastic optical fiber for brachytherapy dosimetry. Also, we have measured relative depth dose rates of Ir-192 source using a fiber-optic sensor and compared them with the results obtained using a conventional EBT film. Cerenkov lights which can be a noise in measuring scintillating light with a fiber-optic sensor are measured and eliminated by using of a background optical fiber. It is expected that a fiber-optic radiation sensor can be used in brachytherapy dosimetry due to its advantages such as a low cost, simple usage and a small volume.

Evaluation of Absorbed Dose According to the Gold Nanoparticle Density in Prostate Cancer Brachytherapy (전립선암의 근접치료 시 금 나노입자 밀도에 따른 흡수선량평가)

  • Lee, Deuk-Hee;Kim, Jung-Hoon
    • Journal of the Korean Society of Radiology
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    • v.13 no.2
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    • pp.247-252
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    • 2019
  • This study was evaluated absorbed dose according to the gold nanoparticle density in prostate brachytherapy which was constantly occurred in Korean men. Absorbed dose evaluation was using MCNPX program which was applied Monte Carlo simulation. Source were applied $^{192}Ir$ which was temporary insertion source and $^{103}Pd$ which was permanently insertion source. And gold nanoparticle density was applied 0 mg, 7 mg, 18 mg and 30 mg. The prostate absorbed dose was increased in proportion to the density 2.95E-14 Gy/e to 4.42E-14 Gy/e in $^{192}Ir$ and showed the same tendency in $^{103}Pd$. And surrounding organ absorbed dose was inversely proportional to the density. Therefore using nanoparticle in brachytherapy was increased therapeutic ratio.