• Progress in Medical Physics
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• v.20 no.1
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• pp.14-20
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• 2009

We measured the dose distribution for spinal cord and tumor using Gafchromic film, applying 3D and 4D-Treatment Planning for lung tumor within the phantom. A measured dose distribution was compared with a calculated dose distribution generated from 3D radiation treatment planning and 4D radiation treatment planning system. The agreement of the dose distribution in tumor for 3D and 4D treatment planning was 90.6%, 97.64% using gamma index computed for a distance to agreement of 1 mm and a dose difference of 3%. However, a gamma agreement index of 3% dose difference tolerence of and 2 mm distance to agreement, the accordance of the dose distribution around cord for 3D and 4D radiation treatment planning was 57.13%, 90.4%. There are significant differences between a calculated dose and a measured dose for 3D radiation treatment planning, no significant differences for 4D treatment planning. The results provide the effectiveness of the 4D treatment planning as compared to 3D. We suggest that the 4-dimensional treatment planning should be considered in the case where such equipments as Cyberknife with the real time tracking system are used to treat the tumors in the moving organ.

• Radiation Oncology Journal
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• v.37 no.1
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• pp.60-65
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• 2019

Purpose: The quality assurance (QA) chart rounds are multidisciplinary meetings to review radiation therapy (RT) treatment plans. This study focus on describing the changes in RT management based on QA round reviews in a single institution. Materials and Methods: After 9 full years of implementation, a retrospective review of all patients whose charts passed through departmental QA chart rounds from 2007 to 2015. The reviewed cases were presented for RT plan review; subcategorized based on decision in QA rounds into: approved, minor modifications or major modifications. Major modification defined as any substantial change which required patient re-simulation or re-planning prior to commencement of RT. Minor modification included treatment plan changes which didn't necessarily require RT re-planning. Results: Overall 7,149 RT treatment plans for different anatomical sites were reviewed at QA rounds. From these treatment plans, 6,654 (93%) were approved, 144 (2%) required minor modifications, while 351 (5%) required major modifications. Major modification included changes in: selected RT dose (96/351, 27%), target volume definition (127/351, 36%), organs-at-risk contouring (10/351, 3%), dose volume objectives/constraints criteria (90/351, 26%), and intent of treatment (28/351, 8%). The RT plans which required major modification according to the tumor subtype were as follows: head and neck (104/904, 12%), thoracic (12/199, 6%), gastrointestinal (33/687,5%), skin (5/106, 5%), genitourinary (16/359, 4%), breast (104/2387, 4%), central nervous system (36/846, 4%), sarcoma (11/277, 4%), pediatric (7/251, 3%), lymphoma (10/423, 2%), gynecological tumors (2/359, 1%), and others (11/351, 3%). Conclusion: Multi-disciplinary standardized QA chart rounds provide a comprehensive and an influential method on RT plans and/or treatment decisions.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.227-230
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• 2011

Pulps were separated from wood chips using an Electron beam irradiation (EBI) treatment without a NaOH-AQ (anthraquinone) treatment for cooking. The methods were based on a hot water treatment after EBI and two-step bleaching processes. Chemical compositions and FT-IR spectroscopy demonstrated that the content of lignin and hemicellulose in the bleached wood pulps treated with various EBI dose decreased with an increase of EBI doses. Specifically, the lignin in the bleached with pulps treated at 600 kGy of EBI dose was almost completely removed. Moreover, TGA analysis showed that a thermal stability increased with increasing the content of cellulose but the lignin decomposed slowly over the wide region.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2613-2617
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• 2015

Radiation induced lung injury has long been considered a treatment limiting factor for patients requiring thoracic radiation. This radiation induced lung injury happens early as well as late. Radiation induced lung injury can occur in two phases viz. early (< 6 months) when it is called radiation pneumonitis and late (>6 months) when it is called radiation induced lung fibrosis. There are multiple factors that can be patient, disease or treatment related that predict the incidence and severity of radiation pneumonitis. Radiation induced damage to the type I pneumocytes is the triggering factor to initiate such reactions. Over the years, radiation therapy has witnessed a paradigm shift in radiation planning and delivery and successfully reduced the incidence of lung injury. Radiation pneumonitis is usually a diagnosis of exclusion. Steroids, ACE inhibitors and pentoxyphylline constitute the cornerstone of therapy. Radiation induced lung fibrosis is another challenging aspect. The pathophysiology of radiation fibrosis includes continuing inflammation and microvascular changes due to pro-angiogenic and profibrogenic stimuli resembling those in adult bronchiectasis. General supportive management, mobilization of airway secretions, anti-inflammatory therapy and management of acute exacerbations remains the treatment option. Radiation induced lung injury is an inevitable accompaniment of thoracic radiation.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.241-244
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• 2004

Radiation treatment with gamma-rays and electron-beams was used to remove polyvinyl alcohol(PVA), one of the main components of dyeing wastewater. PVA was effectively decomposed by radiation treatment, thus the removal was near 100 % at an initial PVA concentration of 44 mg/L. However, total organic carbon(TOC) removal was less than 5 % due to lower transformation of PVA to $CO_2$. This directly indicates the radiation treatment alone is not appropriate for the complete decomposition of PVA. In this sense, the improvement of biodegradability($BOD_5/COD$) of PVA by radiation treatment was studied. Both gamma-ray and electron-beam treatments significantly increased the biodegradability of PVA by transforming non-biodegradable PVA to biodegradable by-products. This suggests radiation treatment, especially electron-beam treatment that showed better improvement of biodegradability, can be used as a pre-treatment of biological degradation process of PVA.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.3
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• pp.937-938
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• 2016

Stereotactic body radiation therapy (SBRT) appears an effective and safe treatment modality for spinal bone metastasis, which can enhance local control and improve quality of life. Life expectation, predicted fracture risk, localization, quality, size and number of metastasis and presence or absence of nerve compression seem to be important factors in decision-making for treatment. Further studies are needed to identify subsets of patient which will most benefit from treatment.

• Radiation Oncology Journal
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• v.36 no.1
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• pp.1-10
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• 2018

Intensity-modulated radiation therapy (IMRT) has been considered the most successful development in radiation oncology since the introduction of computed tomography into treatment planning that enabled three-dimensional conformal radiotherapy in 1980s. More than three decades have passed since the concept of inverse planning was first introduced in 1982, and IMRT has become the most important and common modality in radiation therapy. This review will present developments in inverse IMRT treatment planning and IMRT delivery using multileaf collimators, along with the associated key concepts. Other relevant issues and future perspectives are also presented.

• Journal of radiological science and technology
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• v.42 no.6
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• pp.413-422
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• 2019

Heavy ion particle, represented carbon ion, radiotherapy is currently most advanced radiation therapy technique. Conventional radiation therapy has made remarkable changes over a relatively short period of time and leading various developments such as intensity modulated radiation therapy, 4D radiation therapy, image guided radiation therapy, and high precisional therapy. However, the biological and physical superiority of particle radiation, represented by Bragg peak, can give the maximum dose to tumor and minimal dose to surrounding normal tissues in the treatment of cancers in various areas surrounded by radiation-sensitive normal tissues. However, despite these advantages, there are some limitations and factors to consider. First, there is not enough evidence, such as large-scale randomized, prospective phase III trials, for the clinical application. Secondly, additional studies are needed to establish a very limited number of treatment facilities, uncertainty about the demand for heavy particle treatment, parallel with convetional radiotherapy or indications. In addition, Bragg peak of the heavy particles can greatly reduce the dose to the normal tissues front and behind the tumor compared to the photon or protons. High precision and accuracy are needed for treatment planning and treatment, especially for lungs or livers with large respiratory movements. Currently, the introduction of the heavy particle therapy device is in progress, and therefore, it is expected that more research will be active.

• Radiation Oncology Journal
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• v.7 no.1
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• pp.1-13
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• 1989

Effects of ionizing radiation alone and combined with chemotherapy on tumor growth and it's clonal specificity monitored by changes in distribution of chromosome number were studies in A549 ceil line originated from human adenocarcinoma of the lung. Radiation (300 rad, 600 rad and 900 rad) were delivered with or without 5-FU. Forty eight hours later, 57.5% of growth inhibition of cell w8s seen in cells treated with 5-FU concentration of $0.4{\mu}g/ml$ for 24hr exposure. Cell survival curves after radiation with and without 5-FU were made. Chromosomal analysis of cells in metaphase in control, and in cells treated with 300 rad of radiation, or $0.4{\mu}g/ml$ of 5-FU treatment, and combined treatment of both were done to examine the changes in ploidy and number of chromosome. Radiation combined with S-FU enhanced growth inhibition of A549 cells. However, no evidence of synergegic effects in growth. inhibition was observed in the cells treated with the combination therapy. Pattern of chromosomal distribution of survived cells were shifted from hyperploidy to hypoploidy by single dose of radiation (300 rad). As radiation dose increased a large number of hypoploidy cells were observed. Following treatment of cells with 5-FU, chomosomal distribution of survived cells were also shifted to hypodiploidy which were seen in cells treated with radiation, The ceil treated with 5-FU and fellowed by radiation within 24 hrs had cell with increased number of hypodiploidy cells. Almost same type of chromosomal changes were reproduced in cells treated with combined treatment with radiation and 5-FU. Minor differences were that cells with fewer number of chromosome were more frequent in cells treated with combined therapy. Further increase in cells of hypoploidy (93%) having 1-10 chromosome were induced by additional radiation. Therefore, the enhanced therapeutic effect of 5-FU combined with radiation of A549 cells appeared to be additive rather than synergistic.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.2
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• pp.233-238
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• 2014

Purpose : The Varian's Eclipse radiation treatment planning system is able to correct radiation treatment thought leaf gap which is limitation MLC movement for collision with both MLC. In this study, I'm try to analyze dosimetric effect about the leaf gap in treatment planning system. And then apply to clinical implement. Materials and Methods : The Elclipse version is 10.0. In general, the leaf gap set to 0.05~0.3 mm and must measurement each leaf gap. The leaf gap measured by each LINACs and photons. We applied to measured each leaf gap in IMRT and VMAT. Changing the leaf gap, we evaluated treatment plans by Dmax, CI, etc. Results : When the same plan was evaluated with changing the leaf gap, an increase of 2-5% over the value Dmax, CI increases mm to 0.0~0.50 mm leaf gap. Volumetric modulated and intensity modulated radiation therapy plans all showed the same trend was not found significant between each radiation treatment planning. Conclusion : Generally, the leaf gap setting has a unique measure of the Multileaf collimator. However, the aging of the Multileaf collimator, calibration, and can be changed, after inspection and repair of the lip gap should eventually because these values affect the treatment plan must be applied to the treatment after confirmation. In some cases, may be to maintain the initial setting value of the lip gap, which is undesirable because it can override the influence on the treatment plan.