• 제목/요약/키워드: Korean Society of Radiation Oncology

검색결과 3,081건 처리시간 0.032초

Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

  • Cho, Oyeon;Chun, Mison;Park, Sung Ho;Oh, Young-Taek;Kim, Mi-Hwa;Park, Hae-Jin;Nam, Sang Soo;Heo, Jaesung;Noh, O Kyu
    • Radiation Oncology Journal
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    • 제31권1호
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    • pp.12-17
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    • 2013
  • Purpose: Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. Materials and Methods: From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Results: Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p < 0.001). Mean parotid dose of both glands ${\geq}20$ Gy were observed in 15 (28.3%) for CF and in 0 (0.0%) for MF. The whole brain percentage volumes receiving >98% of prescribed dose were 99.7% for CF and 99.5% for MF. Conclusion: Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

Radiological Characteristics of Materials Used in 3-Dimensional Printing with Various Infill Densities

  • Park, So-Yeon;Choi, Noorie;Choi, Byeong Geol;Lee, Dong Myung;Jang, Na Young
    • 한국의학물리학회지:의학물리
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    • 제30권4호
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    • pp.155-159
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    • 2019
  • Radiological properties of newly introduced and existing 3-dimensional (3D) printing materials were evaluated by measuring their Hounsfield units (HUs) at varying infill densities. The six materials for 3D printing which consisted of acrylonitrile butadiene styrene (ABS), a unique ABS plastic blend manufactured by Zortrax (ULTRAT), high impact polystyrene (HIPS), polyethylene terephthalate glycol (PETG), polylactic acid (PLA), and a thermoplastic polyester elastomer manufactured by Zortrax (FLEX) were used. We used computed tomography (CT) imaging to determine the HU values of each material, and thus assess its suitability for various applications in radiation oncology. We found that several material and infill density combinations resembled the HU values of fat, soft tissues, and lungs; however, none of the tested materials exhibited HU values similar to that of bone. These results will help researchers and clinicians develop more appropriate instruments for improving the quality of radiation therapy. Using optimized infill densities will help improve the quality of radiation therapy by producing customized instruments for each field of radiation therapy.

Stereotactic radiotherapy for early stage non-small cell lung cancer

  • Ricardi, Umberto;Badellino, Serena;Filippi, Andrea Riccardo
    • Radiation Oncology Journal
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    • 제33권2호
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    • pp.57-65
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    • 2015
  • Stereotactic body radiotherapy (SBRT) represents a consolidated treatment option for patients with medically inoperable early stage non-small cell lung cancer (NSCLC). The clinical evidence accumulated in the past decade supports its use as an alternative to surgery with comparable survival outcomes. Due to its limited toxicity, SBRT is also applicable to elderly patients with very poor baseline pulmonary function or other severe comorbidities. Recent comparative studies in operable patients raised the issue of the possible use of SBRT also for this subgroup, with quite promising results that still should be fully confirmed by prospective trials with long-term follow-up. Aim of this review is to summarize and discuss the major studies conducted over the years on SBRT and to provide data on the efficacy and toxicity of this radiotherapy technique for stage I NSCLC. Technical aspects and quality of life related issues are also discussed, with the goal to provide information on the current role and limitations of SBRT in clinical practice.