• Title/Summary/Keyword: Surrounding Dose

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The Evaluation of Hybrid-Volumetric Modulated Arc Therapy for Lung Cancer Radiation Therapy (폐암 방사선 치료 시 Hybrid-Volumetric Modulated Arc Therapy의 유용성 평가)

  • Lee, Geon Ho;Kang, Hyo Seok;Choi, Byoung Joon;Park, Sang Jun;Jung, Da Ee;Lee, Du Sang;Ahn, Min Woo;Jeon, Myeong Soo
    • The Journal of Korean Society for Radiation Therapy
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    • v.29 no.2
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    • pp.19-26
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    • 2017
  • Objectives: In the Lung, the VMAT rotates continuously and examines radiation. That increases the low doses to normal lung. Due to that, the incidence of radiation pneumonia among radiation side effects may increase. The cause of radiation pneumonia is the lower dose area of the lungs. The H-VMAT was applied to patients who applied to reduce radiation in the lower doses of the lungs. We wanted to assess the usefulness of the H-VMAT by comparing the radiation doses to the low dose areas of the lungs and the normal organs. Materials and Methods: A total of 26 patients who applied for a H-VMAT procedure were applied to the patient. The prescription dose applied to total dose 44 Gy from 22 divisions. For each patient, a plan was implemented with Conventional RT, VMAT and H-VMAT. Conventional RT was carried out in four to five fields each, considering the size, location, shape, and location of the PTV. In the case of a VMAT plan, the two Half ARC, three Half ARC method and the two Full ARC were planned. The H-VMAT was planned by adding two Static fields in the VMAT, taking into account the dose of the lung and the tolerance dose of the organs. Results: In the NSCLC, the lung doses $V_5$ and $V_{10}$ of the lungs except for the treatment plan volume were the lowest with $55.40{\pm}13.39%$ and $32.05{\pm}11.37%$ of H-VMAT. And, in the SCLC, the lung doses of V5 and V10 were the lowest at $64.32{\pm}16.15%$ and $35.50{\pm}9.91%$, respectively. The spinal dose of VMAT in NSCLC was $21.15{\pm}4.02Gy$, which was 7.94 Gy lower than other treatment methods. The lowest spinal dose was delivered at $19.72{\pm}1.82Gy$ for SCLC. The mean dose delivered to the esophagus was also $17.44{\pm}2.04Gy$ and $17.84{\pm}9.20Gy$ in SCLC and NSCLC, respectively. Conclusion: When comparing the value of the surrounding normal organ dose, the VMAT showed that less doses were transmitted from the heart, esophagus and spinal cord than the rest of the treatment plan. However, it was similar to VMAT in normal organs except for the spinal cord. VMAT has increased doses of some normal organs but did not exceed the tolerance dose. It showed a low value in $V_5$, $V_{10}$. When comparing Conventional RT, VMAT, and H-VMAT, If the dose to the heart, esophagus and spinal cord is lower than the tolerance dose, it is thought to reduce the incidence of radiation pneumonia by applying H-VMAT that show the benefits of low doses of the lungs.

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Antifungal Activity of a Synthetic Cationic Peptide against the Plant Pathogens Colletotrichum graminicola and Three Fusarium Species

  • Johnson, Eric T.;Evans, Kervin O.;Dowd, Patrick F.
    • The Plant Pathology Journal
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    • v.31 no.3
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    • pp.316-321
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    • 2015
  • A small cationic peptide (JH8944) was tested for activity against a number of pathogens of agricultural crops. JH8944 inhibited conidium growth in most of the tested plant pathogens with a dose of $50{\mu}g/ml$, although one isolate of Fusarium oxysporum was inhibited at $5{\mu}g/ml$ of JH8944. Most conidia of Fusarium graminearum were killed within 6 hours of treatment with $50{\mu}g/ml$ of JH8944. Germinating F. graminearum conidia required $238{\mu}g/ml$ of JH8944 for 90% growth inhibition. The peptide did not cause any damage to tissues surrounding maize leaf punctures when tested at a higher concentration of $250{\mu}g/ml$ even after 3 days. Liposomes consisting of phosphatidylglycerol were susceptible to leakage after treatment with 25 and $50{\mu}g/ml$ of JH8944. These experiments suggest this peptide destroys fungal membrane integrity and could be utilized for control of crop fungal pathogens.

An Image-guided Radiosurgery for the Treatment of Metastatic Bone Tumors using the CyberKnife Robotic System

  • Cho, Chul-Koo
    • The Journal of the Korean bone and joint tumor society
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    • v.13 no.1
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    • pp.14-21
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    • 2007
  • Bone is a common site for metastatic spread from many kinds of malignancies. The morbidity associated with this metastatic spread can be significant, including severe pain. When it comes to spinal metastasis, occupying nearly 40% of skeletal metastases, the risks of complications, such as vertebral body collapse, nerve root impingement, or spinal cord compression, are also significant. Because of the necessity of preserving the integrity of the spinal column and the proximity of critical structures, surgical treatment has limitations when durable local control is desired. Radiotherapy, therefore, is often used as an adjunct treatment or as a sole treatment. A considerable limitation of standard radiotherapy is the reported recurrence rate or ineffective palliation of pain, either clinically or symptomatically. This may be due to limited radiation doses to tumor itself because of the proximity of critical structures. CyberKnife is an image-guided robotic radiosurgical system. The image guidance system includes a kilovoltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator (6 MV) mounted on a robotic arm. Highly conformal fields and hypofractionated radiotherapy schedules are increasingly being used as a means to achieve biologic dose escalation for body tumors. Therefore, we can give much higher doses to the targeted tumor volume with minimizing doses to the surrounding critical structures, resulting in more effective local control and less severe side effects, compared to conventional fractionated radiotherapy. A description of this technology and a review of clinical applications to bone metastases are detailed herein.

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Primary Squamous Cell Carcinoma of the Posterior Glottis (성문후부(Posterior Glottis)에서 원발한 편평상피세포암종 1례)

  • 조승호;김형태;조재홍;김민식
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.9 no.2
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    • pp.160-163
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    • 1998
  • The glottis consists of two parts : The intermembranous portion or the anterior glottis, and the posterior glottis. The posterior glottis has been described by various inappropriate terms such as posterior commissure and interarytenoid region. The structure surrounding the posterior glottis consists of three portions ; The cartilaginous portion of the vocal fold, the lateral wall of the posterior glottis, and the posterior wall of the glottis. The posterior glottis may be a very rare site for primary squamous cell carcinoma of the larynx because of its embriologic and histologic differences from the anterior glottis. Recently we have experienced a case of a 81-year-old woman who had been presented with throat discomfort and voice change for 10months. She had the smoking history of 40 pack-year. The physical examination revealed poorly demarcated, papillary, whitish-pink colored mass on the posterior glottis. The vocal cord mobility was not affected. Biopsy under the suspension larygoscope showed moderately differentiated squamous cell carcinoma. No regional and distant metastasis was found. She was irradiated with 7000cGy over 7 weeks at a daily dose of 200cGy. No evidence of recurrence was found by the fifteenth month following radiation therapy. We report this case with a review of literature.

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Rapid Atypical Progression of Neuro-Behçet's Disease Involving Whole Brainstem and Bilateral Thalami

  • Lee, Sang-Kook;Choi, Sung-Jae;Kim, Sang-Dae;Lim, Dong-Jun
    • Journal of Korean Neurosurgical Society
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    • v.50 no.1
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    • pp.68-71
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    • 2011
  • We present a case of Neuro-Behçet's disease with an unpredictable clinical course. A 47-year-old man was admitted to the neurosurgery department of our hospital with a mild headache. Three days after admission, his consciousness suddenly decreased and respiratory distress progressed rapidly. A brain MRI revealed that the previously observed abnormal signal had extended markedly to both the thalamic areas and the entire brain stem, and the surrounding brain parenchyma were compressed by cerebral edema. Based on the patient's symptoms of recurrent oral and genital ulcers, skin lesions, and uveitis, a rheumatologist made a diagnosis of Behçet's disease with CNS involvement. The patient was treated with high-dose methylprednisolone with respiratory assistance in the intensive care unit for 9 days and his neurologic symptoms improved remarkably. Neuro-Behçet's disease must be considered in the differential diagnosis in rapidly deteriorated young neurological patients along with a stroke, low-grade glioma, multiple sclerosis, and occlusive venous disease.

Reduction of Postoperative Adhesions by a Synthetic Solution of Sodium Carboxymethylcellulose and Dextran or Interceed Following Intestinal Anastomosis in Dogs (개의 장문합술에 있어서 Sodium Carboxymethylcellulose와 Dextran의 합제 및 Interceed)

  • Jang Young-kyu;Kim Hyeon-hui;Lee Hee-chun;Yeon Seong-chan;Lee Hyo-jong
    • Journal of Veterinary Clinics
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    • v.21 no.4
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    • pp.349-354
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    • 2004
  • The effectiveness of a synthetic solution of sodium carboxymethy1cellulose (SCMC) and dextran in the prevention of adhesion formation following intestinal anastomosis of intestine in dogs was elucidated and compared with Interceed. Following induction of adhesion on jejunum of dogs by resection and intestinal anastomosis, the dogs were infused with a synthetic solution of 1% SCMC and 10% dextran in saline in the abdominal cavity at the dose of 5ml/kg of body weight or treated with Interceed membrane. Fourteen days after operation, all the dogs showed adhesion of anastomotic sites to surrounding tissues. The average score of adhesion was 0.50, 0.60 and 0.80 in the dogs infused with the synthetic solution, Interceed membrane and saline solution, respectively. The synthetic solution showed better result of adhesion prevention than Interceed or saline solution. No significant change of body weight, vital signs, hematological values and side effects after operation was found in each group. Therefore, a synthetic solution which is combined with 1% SCMC and 10% dextran in saline can be effectively used for the prevention of adhesion formation comparable to Interceed membrane following intestinal anastomosis in the dogs.

X-Rays through the Looking Glass: Mobile Imaging Dosimetry and Image Quality of Suspected COVID-19 Patients

  • Schelleman, Alexandra;Boyd, Chris
    • Journal of Radiation Protection and Research
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    • v.46 no.3
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    • pp.120-126
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    • 2021
  • Background: This paper aims to evaluate the clinical utility and radiation dosimetry, for the mobile X-ray imaging of patients with known or suspected infectious diseases, through the window of an isolation room. The suitability of this technique for imaging coronavirus disease 2019 (COVID-19) patients is of particular focus here, although it is expected to have equal relevance to many infectious respiratory disease outbreaks. Materials and Methods: Two exposure levels were examined, a "typical" mobile exposure of 100 kVp/1.6 mAs and a "high" exposure of 120 kVp/5 mAs. Exposures of an anthropomorphic phantom were made, with and without a glass window present in the beam. The resultant phantom images were provided to experienced radiographers for image quality evaluation, using a Likert scale to rate the anatomical structure visibility. Results and Discussion: The incident air kerma doubled using the high exposure technique, from 29.47 µGy to 67.82 µGy and scattered radiation inside and outside the room increased. Despite an increase in beam energy, high exposure technique images received higher image quality scores than images acquired using lower exposure settings. Conclusion: Increased scattered radiation was very low and can be further mitigated by ensuring surrounding staff are appropriately distanced from both the patient and X-ray tube. Although an increase in incident air kerma was observed, practical advantages in infection control and personal protective equipment conservation were identified. Sites are encouraged to consider the use of this technique where appropriate, following the completion of standard justification practices.

Radiation prosthetic stents applied to oral cancer patients during the radiation therapy: case reports (효율적 방사선요법을 위한 구강 방사선스텐트의 적용: 증례보고)

  • Nam, Ki Young
    • Journal of Dental Rehabilitation and Applied Science
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    • v.36 no.4
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    • pp.282-288
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    • 2020
  • Radiation prosthetic stent is defined as the customized oral devices which serve for an efficient administration of radiation dose to the affected areas or a minimizing the unnecessary irradiation to surrounding normal tissues during maxillofacial cancer radiotherapy. Since the use of stents is individualized, a close collaboration among radiotherapist, surgeon and prosthodontist is essential thereby which helps in limiting the post-therapy morbidity as well as the stable oral rehabilitation. In this report, two customized stents (bolus carrier and tongue depressing) were fabricated and applied to patient undergone irradiation for soft palate and tongue carcinoma selectively. Multidisciplinary approach can be a proper strategy and recommended for control the sequel of post-irradiation.

Experimental study on the electrochemical properties of zwitterion and phosphate-based hybrid inhibitors in reinforced concrete (양쪽성 이온 및 인산염 기반 하이브리드 방청제의 전기화학적 특성에 관한 실험적 연구)

  • Tran, Duc Thanh;Jeong, Min-goo;Lee, Han-seung;Yang, Hyun-min;Singh, Jitendra Kumar
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.37-38
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    • 2022
  • During the past decades, the corrosion of the steel rebar embedded in concrete structure surrounding marine environment is actually problematic and required the suitable preventive method. An eco-friendly corrosion inhibitor mix is investigated to stifle the active corrosion in comparison with other commercial corrosion inhibitors. The hybrid inhibitor enhances the corrosion resistance and the workability of concrete. However, it reduces the compressive strength slightly after 28-day-age. The electrochemical studies and mechanical studies are pointed out the corrosion resistance property, corrosion kinetics, and the mechanical properties of all concrete samples. H-3 is the optimum dose of hybrid inhbitor that meets the demand of both electrochemical property and mechanical property. It performs the noble features due to the formation of optimum amount of P-Zwitterions-(Cl)-Fe complex onto the steel rebar surface.

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Shielding Evaluation and Activation Analysis of Facilities by Neutron Generator for the Development of 20 Feet Container Inspection System

  • Jin-Woo Lee;Dae-Sung Choi;Gyo-Seong Jeong
    • Journal of Radiation Industry
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    • v.17 no.4
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    • pp.443-449
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    • 2023
  • KAERI(Korea Atomic Energy Research Institute) is conducting research and development of large-scale radiation generators and the latest radiation measuring instruments. In particular, research and development of security screening equipment using an electron beam accelerator and a neutron generator is in progress recently. Globally, 20 ft containers are used to transport imports and exports, and electron beam accelerators are radiation sources to measure the shape of the material inside the container during customs inspections in each country. KAERI is developing a device that can use an electron beam accelerator and a neutron generator sequentially to grasp the shape of various materials as well as the location of the internal target material. In this study, when using the neutron generator, the radiation dose and the degree of activation by neutron for the facility and surrounding environment, facility equipment were simulated using MCNP and FISPACT code. As a result, the shielding structures inside and outside the radiation control area were satisfactory to the reference level established conservatively based on the Korean Nuclear Act.