• Title/Summary/Keyword: Re-irradiation

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Thoracic Re-irradiation for Locally Recurrent Lung Cancer

  • Aktan, Meryem;Kanyilmaz, Gul;Koc, Mehmet;Aras, Serhat
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.5041-5045
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    • 2016
  • Background: Patients with recurrent or progressive lung cancer experience a significant symptom burden, negatively affecting quality of life and reducing life expectancy. Thoracic re-irradiation can be used for palliative treatment to relieve symptoms or as a curative treatment. Methods: Using patient charts, we identified and reviewed 28 cases that had received palliative thoracic re-irradiation for recurrent lung cancer. Results: Before re-irradiation, 32% of patients had stage III non-small cell lung cancer and six had small cell lung cancer. The median interval between treatments was 18.7 months. Median follow-up was 31.2 months from the initial radiotherapy and 5 months after re-irradiation. A better performance status before re-irradiation (<80 vs >80, p=0.09) and a lower overlap 90% isodose (<70 vs >70, p=0.09) showed trends toward improved survival. Grade 1-2 toxicity from re-irradiation was recorded in 12/28 patients, and no grade 3 or 4 acute toxicity was encountered. Conclusion: The role of palliative treatment in survival is not clear but it can provide symptomatic relief in patients, with no high grade toxicity. Further studies with greater patient numbers and longer follow-up times should facilitate determination of the role of this treatment in toxicity and effects on survival.

Appraisal of re-irradiation for the recurrent glioblastoma in the era of MGMT promotor methylation

  • Kim, Il Han
    • Radiation Oncology Journal
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    • v.37 no.1
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    • pp.1-12
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    • 2019
  • Despite recent innovation in treatment techniques and subsequently improved outcomes, the majority of glioblastoma (GBL) have relapses, especially in locoregional areas. Local re-irradiation (re-RT) has been established as a feasible option for recurrent GBL of all ages with safety, tolerability, and effectiveness both in survival and quality of life regardless of fractionation schedule. To keep adverse effects under acceptable range, cumulative dose limit in equivalent dose at 2 Gy fractions by the linear-quadratic model at α/β = 2 for normal brain tissue (EQD2) with narrow margin should be observed and single/hypofractionated re-RT should be undertaken very carefully to recurrent tumor with large volume or adjacent to the brainstem. Promising outcome of re-operation (re-Op) plus re-RT (re-Op/RT) need to be validated and result from re-RT with temozolomide/bevacizumab (TMZ/BV) or new strategy is expected. Development of new-concept prognostic scoring or risk group is required to select patients properly and make use of predictive biomarkers such as O(6)-methylguanine-DNA methyltransferase (MGMT) promotor methylation that influence outcomes of re-RT, re-Op/RT, or re-RT with TMZ/BV.

Improved Uniformity of Resistive Switching Characteristics in Ag/HfO2/Pt ReRAM Device by Microwave Irradiation Treatment (Microwave Irradiation 처리를 통한 Ag/HfO2/Pt ReRAM에서의 메모리 신뢰성 향상에 대한 연구)

  • Kim, Jang-Han;Nam, Ki-Hyun;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.2
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    • pp.81-84
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    • 2014
  • The bipolar resistive switching characteristics of resistive random access memory (ReRAM) based on $HfO_2$ thin films have been demonstrated by using Ag/$HfO_2$/Pt structured ReRAM device. MIcrowave irradiation (MWI) treatment at low temperature was employed in device fabrication with $HfO_2$ thin films as a transition layer. Compared to the as-deposited Ag/$HfO_2$/Pt device, highly improved uniformity characteristics of resistance values and operating voltages were obtained from the MWI treatment Ag/$HfO_2$/Pt ReRAM device. In addition, a stable DC endurance (> 100 cycles) and a high data retention (> $10^4$ sec) were achieved.

Re-irradiation of recurrent esophageal cancer after primary definitive radiotherapy

  • Kim, Young Suk;Lee, Chang Geol;Kim, Kyung Hwan;Kim, Taehyung;Lee, Joohwan;Cho, Yona;Koom, Woong Sub
    • Radiation Oncology Journal
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    • v.30 no.4
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    • pp.182-188
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    • 2012
  • Purpose: For recurrent esophageal cancer after primary definitive radiotherapy, no general treatment guidelines are available. We evaluated the toxicities and clinical outcomes of re-irradiation (re-RT) for recurrent esophageal cancer. Materials and Methods: We analyzed 10 patients with recurrent esophageal cancer treated with re-RT after primary definitive radiotherapy. The median time interval between primary radiotherapy and re-RT was 15.6 months (range, 4.8 to 36.4 months). The total dose of primary radiotherapy was a median of 50.4 Gy (range, 50.4 to 63.0 Gy). The total dose of re-RT was a median of 46.5 Gy (range, 44.0 to 50.4 Gy). Results: The median follow-up period was 4.9 months (range, 2.6 to 11.4 months). The tumor response at 3 months after the end of re-RT was complete response (n = 2), partial response (n = 1), stable disease (n = 2), and progressive disease (n = 5). Grade 5 tracheoesophageal fistula developed in three patients. The time interval between primary radiotherapy and re-RT was less than 12 months in two of these three patients. Late toxicities included grade 1 dysphagia (n = 1). Conclusion: Re-RT of recurrent esophageal cancer after primary radiotherapy can cause severe toxicity.

VERIFICATION OF COSMOS CODE USING IN-PILE DATA OF RE-INSTRUMENTED MOX FUELS

  • Lee, Byung-Ho;Koo, Yang-Hyun;Cheon, Jin-Sik;Oh, Je-Yong;Joo, Hyung-Kook;Sohn, Dong-Seong
    • Proceedings of the Korean Nuclear Society Conference
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    • 2002.05a
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    • pp.242-242
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    • 2002
  • Two MIMAS MaX fuel rods base-irradiated in a commercial PWR have been reinstrumented and irradiated at a test reactor. The fabrication data for two MOX roda are characterized together with base irradiation information. Both Rods were reinstrumented to be fitted with thermocouple to measure centerline temperature of fuel. One rod was equipped with pressure transducer for rod internal pressure whereas the other with cladding elongation detector. The post irradiation examinations for various items were performed to determine fuel and cladding in-pile behavior after base irradiation. By using well characterized fabrication and re-instrumentation data and power history, the fuel performance code, COSMOS, is verified with measured in-pile and PIE information. The COMaS code shows good agreement for the cladding oxidation and creep, and fission gas release when compared with PIE dad a after base irradiaton. Based on the re-instrumention information and power history measured in-pile, the COSMOS predicts re-instrumented in-pile thermal behaviour during power up-ramp and steady operation with acceptable accuracy. The rod internal pressure is also well simulated by COSMOS code. Therfore, with all the other verification by COSMOS code up to now, it can be concluded that COSMOS fuel performance code is applicable for the design and license for MaX fuel rods up to high burnup.

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Histological Change and Collagen Formation on Laser Wounded Rat using 808 nm Diode Laser and $CO_2$ Laser

  • Chung, Phil-Sang;Shin, Jang-In;Chang, So-Young;Ahn, Jin-Chul
    • Biomedical Science Letters
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    • v.15 no.1
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    • pp.81-86
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    • 2009
  • Lasers are necessity in our life related to the fields of medicine and cosmetic surgery. With 808 nm diode laser and $CO_2$ laser, we made some wounds on a dorsum of rat by laser irradiation. All of irradiations shows thermal effects on the whole region of skin tissues. They make wound damage depending on laser power and irradiation time. Because a collagen is plays an important role in tissue repair, we studied collagen accumulation in wound tissue. For wound healing, collagen accumulation was found in the near region of damage in epidermis and dermis layer of the rat skin. In case of the quantitative analysis of collagen in wound tissue, the amount of collagen in wound tissue by $CO_2$ laser irradiation is higher than that of 808 nm diode laser irradiation. And re-epithelialization was significantly faster in wound by $CO_2$ laser irradiation compared with that of 808 nm diode laser irradiation.

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[ $^{188}Re$ ]-Labeled Radiopharmaceuticals ($^{188}Re$ 표지 방사성의약품)

  • Jeong, Jae-Min
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.5
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    • pp.293-300
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    • 2001
  • The search for an ideal radioisotope for radiotherapy continues. As a generator-produced radioisotope emitting both beta and gamma rays with a short physical half-life of 16.9 hr, $^{188}Re$ is an excellent candidate for radiotherapy. Its applications Include the irradiation of coronary artery to prevent restenosis, treatment of rheumatoid arthritis, treatment of peritoneal effusion, palliation of metastatic bone pain, and treatment of liver cancer.

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Beryllium oxide utilized in nuclear reactors: Part II, A systematic review of the neutron irradiation effects

  • Ming-dong Hou;Xiang-wen Zhou;Bing Liu
    • Nuclear Engineering and Technology
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    • v.55 no.2
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    • pp.408-420
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    • 2023
  • Beryllium oxide (BeO) is being re-emphasized and utilized in Micro Modular Reactors (MMR) because of its prominent nuclear and high temperature properties in recent years. The implications of the research about effects of neutron irradiation on the microstructure and properties of BeO are significant. This article comprehensively reviews the effects of neutron irradiation on BeO and proposes the maximum permissible neutron doses at different temperatures for BeO without cracks in appearance according to the data in the previous literature. This maximum permissible neutron dose value has important reference significance for the experimental study of BeO. The effects of neutron irradiation on the thermal conductivity and flexural strength of BeO are also discussed. In addition, microstructure evolution of irradiated BeO during post-irradiation annealing is summarized. This review article has important implications for the application of BeO in MMR.

Dosimetry and MIRD for Re-188 Liquid Balloons (Re-188-DTPA 풍선 주위 선량분포와 의용내부피폭선량)

  • Lee, Dong-Soo;Lee, Jin
    • 대한핵의학회:학술대회논문집
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    • 1999.05a
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    • pp.222-227
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    • 1999
  • Re-188 is suitable for endovascular liquid-balloon brachytherapy for the prevention of restenosis after angioplasty. Re-188 was concentrated to 3700 MBq/ml and labeled with DTPA. According to dosimetric calculation, it took 420 seconds using Re-188 solution with concentration of 3700 MBq/ml to irradiate 17.6 Gy to the target at 1 mm from the balloon surface. Software was made to estimate the irradiation time. MIRD calculation with dynamic bladder model yielded the whole body dose of Re-188-DTPA as 0.005 mGy/MBq in case of balloon rupture and release of the whole amount into the blood.

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