• 대한방사선기술학회지:방사선기술과학
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• 제43권4호
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• pp.259-264
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• 2020

Radiation causes radiation hazards in the human body. In Korea, a case of radiation necrosis occurred in 2014. In this study, the scatter and shielding efficiency according to lead shielding were classified into epidermis and dermis for 0.511 MeV used in nuclear medicine. In this study, experiments were conducted using the slab phantom that represents calibration and the dose of human trunk. Experimental results showed that the shielding rate of 0.25 mmPb was 180% in the epidermis and 96% in the dermis. Shielding at 0.5mmPb showed shielding rates of 158%in the epidermis and 82% in the dermis. As a result of measuring the absorbed dose by subdividing the thickness of the dermis into 0.5 mm intervals, when the shielding was carried out at 0.25 mmPb, the dose appeared to be about 120% at 0.5 mm of the dermis surface, and the dose was decreased at the subsequent depth. Shielding at 0.5 mmPb, the dose appeared to be about 101% at the surface 0.5 mm, and the dose was measured to decrease at the subsequent depth. This result suggests that when lead aprons are actually used, the scattering rays would be sufficiently removed due to the spaces generated by the clothes and air, Therefore, the scattered ray generated from lead will not reach the human body. The ICRU defines the epidermis (0.07), in which the radiation-induced damage of the skin occurs, as the dose equivalent. If the radiation dose of the dermis is considered in addition, it will be helpful for the evaluation of the prognosis for radiation hazard of the skin.

• 대한기관식도과학회지
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• 제7권2호
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• pp.184-187
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• 2001

Peripheral T-cell lymphoma, which characterized by progressive ulceration and necrosis of the upper aerodigestive tract or midline facial structures, is rare disease in the otolaryngologic field. We recently experienced a case, revealed histopathologically peripheral T-cell lymphoma, involving inferior turbinate without any evidence of involving other organs. In this paper, we report two cases of peripheral T-cell lymphoma who was treated chemotherapy and concurrent radiation therapy.

• 대한치과의사협회지
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• 제56권7호
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• pp.385-390
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• 2018

Laser means "Light amplification by stimulated emission of radiation". Laser have unique characteristics according to wavelength. Wavelenth of Waterlase is 2780nm and it can be absorbed to water and hydroxyapatite. When laser is applied to some material, its temperature goes up due to laser's energy. But in dental treatment high temperature is not good for teeth. High temperature can make dental pulp and bone necrosis. Waterlase can be absorbed to water droplet, so when it burst, it can cut soft and hard tissue without raising temperature. so it is so proper to dental treatment.

• 대한방사선협회지
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• 제28권1호
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• pp.39-48
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• 2002

The Green tea, one of the most popular and favorite drinks in eastern societies, has been reported to have various therapeutic properties. These includes anti-cancer, anti-oxident, anti-endocrine disrupter effects. Its anti-cancer effect was said to be ac

• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2005년도 Proceedings of The 2nd Asian Society of Veterinary Pathology Symposium(Vol.2) and 2005 Annual Meeting of The Korean Society of Veterinary Pathology(Vol.9)
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• pp.64-64
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• 2005

• Journal of Korean Neurosurgical Society
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• 제64권6호
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• pp.983-994
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• 2021

Objective : The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). Methods : We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1-3 and 3-5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. Results : After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0-17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150-0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5-11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. Conclusion : The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

• Tuberculosis and Respiratory Diseases
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• 제73권6호
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• pp.325-330
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• 2012

High-dose-rate endobronchial brachytherapy (HDREB) have been used as the treatment of early endobronchial cancer, as well as for palliation of advanced cancer. However, fatal hemoptysis can occur after HDREB at the rate of 7~32%. We report a case of massive hemoptysis due to radiation bronchitis developed after HDREB. A 67-year-old man was treated with HDREB for early endobronchial cancer on the left upper lobe bronchus. He complained of persistent cough from 4 weeks after completion of HDREB. Radiation bronchitis was observed on the bronchoscopy at 34 weeks, and it was progressed from mucosal swelling and exudate formation to necrosis and ulceration without local relapse. In addition, he died of massive hemoptysis after 15 months. The patient had no sign or radiologic evidences to predict the hemoptysis. This case implies that HDREB directly contributes to an occurrence of a fatal hemoptysis, and follow-up bronchoscopy is important to predict a progression of radiation bronchitis and fatal hemoptysis.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3561-3566
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• 2014

Background: Recurrent nasopharyngeal carcinoma (NPC) after previous radiotherapy is challenging. There is no standard approach for salvage treatment. Here we present toxicity and treatment results for recurrent NFC patients who underwent fractionated stereotactic radiotherapy (FSRT) as second line radiotherapy (RT). Materials and Methods: Between April 2009 and July 2012, 24 patients, with a male to female ratio of 3:1, were treated with CykerKnife$^{(R)}$ FSRT for recurrent NFC in our institution. Seven out of 24 patients had metastatic recurrent disease. Median age was 53 years (range, 20-70 years). Initial RT dose was 70Gy. The time period between initial RT and FSRT was a median of 33.2 months. The median prescription dose for FSRT was 30Gy (range, 24-30 Gy) in a median of 5 fractions (range, 4-6). Results: The median follow-up for all patients was 19.5 months (IQR: 12.2.-29.2 months). The locoregional control; progression free survival and overall survival (OS) rates for 1-, 2- and 3-year were 64%, 38%, 21%; 60%, 30%, 17% and 83%, 43%, 31%, respectively. Median OS for the entire cohort was 22 months (95% CI: 16.5-27.5). On multivariate analysis recurrent tumor stage was the only prognostic factor for OS (p=0.004). One patient exhibited grade III temporal lobe necrosis. One died because of grade IV mucositis and overlapping infection. Conclusions: The treatment of recurrent NPC is controversial. Fractionated stereotactic radiotherapy is promising. However, the published trials are heterogeneous with respect to the selection criteria and treatment details. Prospective studies with long term follow-up data are warranted.

• 대한핵의학회지
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• 제6권2호
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• pp.7-20
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• 1972

Experimental radiation nephritis was produced in 15 rabbits by X-irradiation. About $2,000{\gamma}$ (tissue doses) were given to both kidneys of a rabbit in 5 days. Other tissues and organs except both kidneys were protected with 2mm thickened lead plates. 5 weeks after the last irradiation, blood pictures, blood pressures, B.U.N., serum creatinine, Ca, Mg, Fe levels and serum erythropoietin activity of the irradiated rabbits were studied. After finishing above studies, rabbits were sacrificed and both kidneys were removed and examined histopathologically. Same laboratory and pathological studies were performed in 6 control rabbits. In this study, the author obtained following results. 1) Both kidneys of rabbitis with experimental raditation nephritis showed marked histopathological changes, i.e.: renal tubules showed diffuse cloudy swelling, impacted intraluminal hyaline casts and focal precipitations of lime salts on the tubular epithelium. Diffuse interstitial fatty necrosis and various degrees of fibrotic infiltrations on the interstitium were also seen in association with focal lymphocytic infiltrations. Hyaline degenerations were observed on the glomeruli and small vessels. 2) Experimental radiation nephritis rabbits showed marked lowering in R.B.C. counts, decreased hemoglobin levels, low hematocrit values and leucopenia in comparison with those of control rabbits. (P<0.01). (Table 1 & 2). 3) Mild proteinuria were observed in experimental radiation nephritis in rabbits. 4) The levels of B.U.N. and serum creatinine increased in experimental radiation nephritis. (P<0.01). (Table 1,3 & 4) 5) The levels of serum Ca and Mg Showed no statistical difference in comparison with those of control rabbits. (P>0.05) (Table 3 & 4). 6) No statistical correlations were observable between the levels of B.U.N. and Hb. values. (${\gamma}=-0.223$) No close correlations (${\gamma}=-0.328$) were noticed between the levels of B.U.N. and serum iron levels. 7) Erythropoietin activity (R.B.C. $^{59}Fe$ Incorporation) was measured by the modified Fried method. No change in its activity was noticed in radiation nephritis group comparing with that of the control group. (P>0.05). (Table 1,3 & 5). 8) Carotid artery blood pressures showed also no difference. (P>0.05). (Table 1 & 2).

• Journal of Korean Neurosurgical Society
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• 제67권4호
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• pp.458-466
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• 2024

Objective : Several clinical studies have explored the feasibility and efficacy of radiosurgical treatment for mesial temporal lobe epilepsy, but the long-term safety of this treatment has not been fully characterized. This study aims to report and describe radiation-induced cavernous malformation as a delayed complication of radiosurgery in epilepsy patients. Methods : The series includes 20 patients with mesial temporal lobe epilepsy who underwent Gamma Knife radiosurgery (GKRS). The majority received a prescribed isodose of 24 Gy as an adjuvant treatment after anterior temporal lobectomy. Results : In this series, we identified radiation-induced cavernous malformation in three patients, resulting in a cumulative incidence of 18.4% (95% confidence interval, 6.3% to 47.0%) at an 8-year follow-up. These late sequelae of vascular malformation occurred between 6.9 and 7.6 years after GKRS, manifesting later than other delayed radiation-induced changes, such as radiation necrosis. Neurological symptoms attributed to intracranial hypertension were present in those three cases involving cavernous malformation. Of these, two cases, which initially exhibited an insufficient response to radiosurgery, ultimately demonstrated seizure remission following the successful microsurgical resection of the cavernous malformation. Conclusion : All things considered, the development of radiation-induced cavernous malformation is not uncommon in this population and should be acknowledged as a potential long-term complication. Microsurgical resection of cavernous malformation can be preferentially considered in cases where the initial seizure outcome after GKRS is unsatisfactory.