• 제목/요약/키워드: Radiation dose

검색결과 4,964건 처리시간 0.038초

Gamma Knife Radiosurgery for Metastatic Brain Tumors with Exophytic Hemorrhage

  • Park, Eun Suk;Lee, Eun Jung;Yun, Jung-Ho;Cho, Young Hyun;Kim, Jeong Hoon;Kwon, Do Hoon
    • Journal of Korean Neurosurgical Society
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    • 제61권5호
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    • pp.592-599
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    • 2018
  • Objective : Metastatic brain tumors (MBTs) often present with intracerebral hemorrhage. Although Gamma Knife surgery (GKS) is a valid treatment option for hemorrhagic MBTs, its efficacy is unclear. To achieve oncologic control and reduce radiation toxicity, we used a radiosurgical targeting technique that confines the tumor core within the hematoma when performing GKS in patients with such tumors. We reviewed our experience in this endeavor, focusing on local tumor control and treatment-associated morbidities. Methods : From 2007 to 2014, 13 patients with hemorrhagic MBTs were treated via GKS using our targeting technique. The median marginal dose prescribed was 23 Gy (range, 20-25). GKS was performed approximately 2 weeks after tumor bleeding to allow the patient's condition to stabilize. Results : The primary sites of the MBTs included the liver (n=7), lung (n=2), kidney (n=1), and stomach (n=1); in two cases, the primary tumor was a melanoma. The mean tumor volume was $4.00cm^3$ (range, 0.74-11.0). The mean overall survival duration after GKS was 12.5 months (range, 3-29), and three patients are still alive at the time of the review. The local tumor control rate was 92% (tumor disappearance 23%, tumor regression 46%, and stable disease 23%). There was one (8%) instance of local recurrence, which occurred 11 months after GKS in the solid portion of the tumor. No GKS-related complications were observed. Conclusion : Our experience shows that GKS performed in conjunction with our targeting technique safely and effectively treats hemorrhagic MBTs. The success of this technique may reflect the presence of scattered metastatic tumor cells in the hematoma that do not proliferate owing to the inadequate microenvironment of the hematoma. We suggest that GKS can be a useful treatment option for patients with hemorrhagic MBTs that are not amenable to surgery.

NaOH를 이용한 우드칩의 당화 전처리에 대한 감마선 조사 영향 연구 (Effect of Gamma Irradiation on Wood Chip Saccharification Pretreated with NaOH)

  • 김수미;최종일;조민호;김종덕
    • Korean Chemical Engineering Research
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    • 제54권3호
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    • pp.431-435
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    • 2016
  • 본 논문에서는 감마선 조사가 NaOH 전처리를 이용한 우드칩의 당화에 미치는 영향을 살펴보았다. 당화량은 전처리된 우드칩에 효소를 이용하여 가수분해한 후 생성된 환원당과 포도당 양을 측정하여 확인하였다. 10 g/L NaOH 처리한 우드칩을 각각 50, 100, 200 kGy 세기의 감마선을 조사하여 당화량을 측정하였다. 우드칩의 가수분해 수율을 비교했을 때, 200 kGy 감마선 조사한 우드칩에서 가장 높은 환원당 함량 12.2 g/L이 얻어졌다. 또한 전처리 과정에서의 감마선 조사 단계의 영향을 평가하기 위하여 우드칩을 먼저 50, 100, 200 kGy 감마선 조사한 후, 10 g/L NaOH 로 전처리하였다. 200 kGy 감마선 조사 후 NaOH 전처리를 수행했을 때 환원당 함량은 13.4 g/L로 전처리 이후의 감마선 조사구보다 증가하였고, 7.9 g/L 포도당을 얻을 수 있었다. 이러한 결과로부터 감마선 조사가 셀루로오즈 바이오매스 전처리에 활용 가능할 것으로 기대된다.

RW3 고체팬텀에서 고에너지 X-선에 대한 전리함 반응보정인자의 특성에 관한 연구 (Study on the Characteristics of Response Correction Factor of Ionization Chamber in RW3 Solid Phantom for High Energy X-rays)

  • 이정옥;정동혁;김부길
    • 대한방사선기술학회지:방사선기술과학
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    • 제32권2호
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    • pp.205-212
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    • 2009
  • 반응보정인자(h)는 고체팬텀에서 전리함의 반응을 물에서의 값으로 변환하기 위한 인자이다. RW3 고체 팬텀의 경우에 고에너지 X-선에 대한 반응보정인자는 선질과 깊이에 의존하는 것으로 알려져 있으나 조사면 크기와 SSD(Source to surface distance), 그리고 전리함 종류에 따른 의존성은 알려진 바가 없다. 본 연구에서는 알려진 의존성을 고찰하고 알려지지 않은 인자들에 대한 의존성을 조사하였다. 본 측정에서는 파머형전리함(FC65G, IBA, Germany)과 소형전리함(CC13, IBA, Germany)이 사용되었으며 대상 선질은 6 MV와 15 MV X-선이었다. 측정 결과 반응보정인자는 6 MV의 경우에 깊이 5 cm와 10 cm에서 각각 h = 1.015, 1.021, 그리고 15 MV의 경우에 깊이 5와 10 cm에서 각각 h = 1.024, 1.029로 나타났다. 결론적으로 반응보정인자는 선질과 깊이에는 의존하였지만 조사면 크기와 SSD에 따른 변화는 적었다. 전리함에 있어서 대상의 두 전리함에 대해서는 차이가 없었으나 다른 종류의 전리함에 대해서 추가적 연구가 필요하다고 생각한다. 본 결과는 RW3에서 전리함을 이용한 측정시 측정값의 분석에 활용될 수 있다.

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Dendrobium speciosum 에탄올 추출물의 melanin 생성 억제 효능 및 주름개선 효과 (Anti-melanogenesis and Anti-wrinkle Properties of Korean Native Dendrobium speciosum Ethanol Extract)

  • 심미옥;이효은;장지훈;정호경;김태묵;김민석;정원석
    • 한국자원식물학회지
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    • 제29권2호
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    • pp.155-162
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    • 2016
  • 본 연구에서는 Dendrobium speciosum 에탄올추출물의 티로시나아제 억제를 통한 멜라닌형성 저해 효과 및 주름개선효과에 대해 연구하였다. Dendrobium speciosum추출물은 α-MSH만 처리한 군에 비해 티로시나아제 활성을 농도 의존적으로 저해시킴으로서 멜라닌 함량을 감소시켰다. 더 자세한 메카니즘을 알아보기 위하여 멜라닌 합성 관련 유전자인 Tyrosinase-related protein-1, tyrosinase-related protein-2, Microphthalmia-associated transcription factor 발현을 확인하였을 때 Dendrobium speciosum처리군에서 유전자 발현이 농도 의존적으로 감소하였다. 또한 Dendrobium speciosum처리 시 type I procollagen 합성이 증가함으로써 Dendrobium speciosum처리가 collagen 생합성을 증대시킬 것으로 사료된다. 이 결과를 바탕으로 Dendrobium speciosum에탄올 추출물 처리 시 멜라닌합성 관련 유전자의 발현 및 티로시나아제 활성을 저해시켜 멜라닌 합성이 감소됨에 따라 효과적인 미백활성을 가지며 collagen합성을 증대시킴으로서 주름개선에 탁월한 효과를 가지는 것으로 사료되며 이는 기능성 화장품 소재로 사용가능할 것으로 사료된다.

Gamma Knife Radiosurgery for Brainstem Metastasis

  • Yoo, Tae-Won;Park, Eun-Suk;Kwon, Do-Hoon;Kim, Chang-Jin
    • Journal of Korean Neurosurgical Society
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    • 제50권4호
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    • pp.299-303
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    • 2011
  • Objective : Brainstem metastases are rarely operable and generally unresponsive to conventional radiation therapy or chemotherapy. Recently, Gamma Knife Radiosurgery (GKRS) was used as feasible treatment option for brainstem metastasis. The present study evaluated our experience of brainstem metastasis which was treated with GKRS. Methods : Between November 1992 and June 2010, 32 patients (23 men and 9 women, mean age 56.1 years, range 39-73) were treated with GKRS for brainstem metastases. There were metastatic lesions in pons in 23, the midbrain in 6, and the medulla oblongata in 3 patients, respectively. The primary tumor site was lung in 21, breast in 3, kidney in 2 and other locations in 6 patients. The mean tumor volume was $1,517mm^3$ (range, 9-6,000), and the mean marginal dose was 15.9 Gy (range, 6-23). Magnetic Resonance Imaging (MRI) was obtained every 2-3 months following GKRS. Follow-up MRI was possible in 24 patients at a mean follow-up duration of 12.0 months (range, 1-45). Kaplan-Meier survival analysis was used to evaluate the prognostic factors. Results : Follow-up MRI showed tumor disappearance in 6, tumor shrinkage in 14, no change in tumor size in 1, and tumor growth in 3 patients, which translated into a local tumor control rate of 87.5% (21 of 24 tumors). The mean progression free survival was 12.2 months (range, 2-45) after GKRS. Nine patients were alive at the completion of the study, and the overall mean survival time after GKRS was 7.7 months (range, 1-22). One patient with metastatic melanoma experienced intratumoral hemorrhage during the follow-up period. Survival was found to be associated with score of more than 70 on Karnofsky performance status and low recursive partitioning analysis class (class 1 or 2), in terms of favorable prognostic factors. Conclusion : GKRS was found to be safe and effective for management of brainstem metastasis. The integral clinical status of patient seems to be important in determining the overall survival time.

방사선 조사가 백서 악하선 줄무늬관세포에 미치는 영향에 관한 투과전자현미경적 연구 (AN ELECTRON MICROSCOPIC STUDY OF THE IRRADIATION EFFECTS ON THE STRIATED DUCT CELLS OF THE SUBMANDIBULAR GLAND IN RATS)

  • 이규찬;이상래
    • 치과방사선
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    • 제20권2호
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    • pp.171-182
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    • 1990
  • The purpose of this study was to investigate the effects of irradiation on the striated duct cells of the rat submandibular gland ductal tissues which control the characteristics of saliva. For this study, the experimental group was composed of 36 irradiated Sprague Dawley strain rats divided into 8 subgroups 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours, 48 hours, 72 hours after irradiation. 4 non-irradiated rats were used as the control group. The experimental animals were singly irradiated with a dose of 18Gy gamma ray to their head and neck region by the Co-6- teletherapy unit and sacrificed after each experimental duration. The specimens were examined with a light microscope with an H-E stain and with a trans- mission electron microscope. The results of this study were as follows. In the light micrograph, a severe atrophic change occurred in the striated duct cells at 2hours after irradiation and gradual recovery occurred from 6 hours after irradiation. 2. The nuclear chromosomes of the striated duct cells were changed granular at 2 hours after irradiation. Recovery was observed at 6 hours after irradiation. Nuclear bodies were also observed from 3 hours after irradiation. 3. The mitochondria of the striated duct cells had indistinct cristae at 2 hours after irradiation, and were degenerated or swollen at 3 hours after irradiation. They recovered, however, from 6 hours, with an increasing number at 48 hours and a regular arrangement was observed at 72 hours after irradiation. 4. The microvilli showed atrophic changes at 2 hours after irradiation and were almost lost at 3 hours after irradiation. They were observed again from 48 hours after irradiation. 5. The rough endoplasmic reticulum and golgi body were not apparent at 1 hour after irradiation and were dilated with degeneration 2 hours after, but intact rough endoplasmic reticulum were observed from 3 hours after irradiation and developed well at 24 hours after irradiation. By the result of this study, showing a mild change in the functional morphology of the salivary striated duct cells immediately following irradiation, it is considered that the many complications which occur after radiation therapy, will disappear in time with the histological and the functional recovery of the glandular tissues.

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Role of Concomitant Chemoradiation in Locally Advanced Head and Neck Cancers

  • Lasrado, Savita;Moras, Kuldeep;Pinto, George Jawahar Oliver;Bhat, Mahesh;Hegde, Sanath;Sathian, Brijesh;Luis, Neil Aaron
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권10호
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    • pp.4147-4152
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    • 2014
  • Standard therapy for advanced head and neck cancer consists of a combination of surgery and radiation. However, survival of this patient population has not improved during the past 20 years. Many different multimodality treatment schedules have been proposed, and chemotherapy is often used with the intent of organ preservation. The present study was intended to establish the efficacy of concomitant chemoradiation with a single agent carboplatin in advanced head and neck cancers.The objectives were to investigate the feasibility of concomitant administration of carboplatin, monitor acute toxicity during radiotherapy, and determine subacute side effects, such as wound healing following surgery after chemoradiotherapy. A prospective study was conducted wherein a total of 40 patients with stage III and IV squamous cell carcinomas of oral cavity, oropharynx, hypopharynx and larynx were enrolled. All patients were treated with external beam radiotherapy and weekly carboplatin area under curve (AUC of 5). Radiotherapy was given in single daily fractions of 1.8-2 grays (Gy) to a total dose of 66-72 Gy. Salvage surgery was performed for any residual or recurrent locoregional disease. Neck dissection was recommended for all patients with neck disease showing less than a complete response after chemoradiation. A total of 40 patients were enrolled of whom 32 were males and 8 were females. Highest incidence of cancer was seen in the 5th-6th decades of life with a median age of 47.7 years. Oropharyngeal tumours constituted a maximum of 21 patients followed by hypopharynx in 10, larynx in 7 and oral cavity in 2. 80% of the patients had a neck node on presentation of which 40% had N2-N3 nodal status. TNM staging revealed that 58% of patients were in stage III and 43% in stage IV. Evaluation of acute toxicity revealed that 50% had grade II mucositis, 25% grade III mucositis, 2.5% grade IV mucositis. 50% of patients had grade I skin reactions, 65% of patients had grade I thrombocytopenia, and 24% of patients had grade I anaemia. After completion of treatment 65% of patients had complete response at the primary and regional sites, and 35% of patients had a partial response of whom 23% underwent neck dissection and 5% of them underwent salvage surgery at the primary site. At the end of one year there were six deaths and four recurrences and 70% were free of disease. Concurrent chemoradiation with carboplatin provided good locoregional control for locally advanced head and neck cancers. This regimen, although toxic, is tolerable with appropriate supportive intervention. Primary site conservation is possible in many patients. Chemoradiotherapy appears to have an emerging role in the primary management of head and neck cancers.

Efficacy of Ginger in Control of Chemotherapy Induced Nausea and Vomiting in Breast Cancer Patients Receiving Doxorubicin-Based Chemotherapy

  • Ansari, Mansour;Porouhan, Pezhman;Mohammadianpanah, Mohammad;Omidvari, Shapour;Mosalaei, Ahmad;Ahmadloo, Niloofar;Nasrollahi, Hamid;Hamedi, Seyed Hasan
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권8호
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    • pp.3877-3880
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    • 2016
  • Nausea and vomiting are among the most serious side effects of chemotherapy, in some cases leading to treatment interruption or chemotherapy dose reduction. Ginger has long been known as an antiemetic drug, used for conditions such as motion sickness, nausea-vomiting in pregnancy, and post-operation side effects. One hundred and fifty female patients with breast cancer entered this prospective study and were randomized to receive ginger (500 mg ginger powder, twice a day for 3 days) or placebo. One hundred and nineteen patients completed the study: 57 of them received ginger and 62 received ginger for the first 3 chemotherapy cycles. Mean age in all patients was 48.6 (25-79) years. After 1st chemotherapy, mean nausea in the ginger and control arms were 1.36 (${\pm}1.31$) and 1.46 (${\pm}1.28$) with no statistically significant difference. After the $2^{nd}$ chemotherapy session, nausea score was slightly more in the ginger group (1.36 versus 1.32). After $3^{rd}$ chemotherapy, mean nausea severity in control group was less than ginger group [1.37 (${\pm}1.14$), versus 1.42 (${\pm}1.30$)]. Considering all patients, nausea was slightly more severe in ginger arm. In ginger arm mean nausea score was 1.42 (${\pm}0.96$) and in control arm it was 1.40 (${\pm}0.92$). Mean vomiting scores after chemotherapy in ginger arm were 0.719 (${\pm}1.03$), 0.68 (${\pm}1.00$) and 0.77 (${\pm}1.18$). In control arm, mean vomiting was 0.983 (${\pm}1.23$), 1.03 (${\pm}1.22$) and 1.15 (${\pm}1.27$). In all sessions, ginger decreased vomiting severity from 1.4 (${\pm}1.04$) to 0.71 (${\pm}0.86$). None of the differences were significant. In those patients who received the AC regimen, vomiting was less severe ($0.64{\pm}0.87$) comparing to those who received placebo ($1.13{\pm}1.12$), which was statistically significant (p-Value <0.05). Further and larger studies are needed to draw conclusions.

2-deoxy-D-glucose와 quercetin이 방사선조사 MC3T3-E1 골모세포주의 분화와 석회화에 미치는 영향 (Effects of 2-deoxy-D-glucose and quercetin on osteoblastic differentiation and mineralization in irradiated MC3T3-E1 cells)

  • 안현숙;김경아;고광준
    • Imaging Science in Dentistry
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    • 제36권4호
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    • pp.189-198
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    • 2006
  • Purpose: To investigate the in vitro response of MC3T3-E1 osteoblastic cells to X-ray in the presence and absence of 2 deoxy-D-glucose (2-DG) and quercetin (QCT). Materials and Methods: The MC3T3-E1 cells were cultured in an ${\alpha}-MEM$ supplemented with 5 mM 2-DG or $10{\mu}M$ QCT and then the cells were incubated for 12 h prior to irradiation with 2, 4, 6, and 8Gy using a linear accelerator (Mevaprimus, Germany) delivered at a rate of 1.5 Gy/min. At various times after the irradiation, the cells were processed for the analyses of proliferation, viability, cytotoxicity, and mineralization. Results: Exposure of the cells to X-ray inhibited the tritium incorporation, 3-(4, 5-dimethylthiazol-2yl-)-2, 5-diphenyl tetrazolium bromide (MTT)-reducing activity, and alkaline phosphatase (ALP) activity, and caused cytotoxicity and apoptosis in a dose-dependent manner of the X-ray. This effect was further apparent on day 3 and 7 after the irradiation. RA+2-DG showed the decrease of DNA content, cell viability, and increase of cytotoxicity rather than RA. ALP activity increased on day 7 and subsequently its activity dropped to a lower level. 2-DG suppressed the calcium concentration, but visual difference of number of calcified nodules between RA and RA+2-DG was not noticed. RA+QCT showed the increase of DNA content, cell viability, but decrease of cytotoxicity and subG1 stage cells in the cell cycle, and increased calcified nodules in von Kossa staining rather than the RA. ALP activity showed significant increases on day 7 and subsequently its activity dropped to a lower level. Conclusion: The results showed that the 2-DG acted as a radiosensitizing agent and QCT acted as a radiosensitizing agent respectively in the irradiated MC3T3-E1 osteoblast-like cells.

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하악 무치악 부위의 임플란트 이식을 위한 전산화단층촬영 영상의 비교 평가 (Comparative evaluation of computed tomography for dental implants on the mandibular edentulous area)

  • 선경훈;정호걸;박혁;박창서;김기덕
    • Imaging Science in Dentistry
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    • 제39권1호
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    • pp.27-33
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    • 2009
  • Purpose: The purpose of this study was to evaluate the clinical usefulness of the recently developed multi-detector computed tomography and cone beam computed tomography in pre-operative implant evaluation, by comparing them with the single detector computed tomography, already confirmed for accuracy in this area. Materials and Methods: Five partially edentulous dry human mandibles, with $1{\times}1mm$ gutta percha cones, placed in 5mm intervals posterior to the mental foramen on each side of the buccal part of the mandible, were used in this study. They were scanned as follows: 1) Single detector computed tomography: slice thickness 1mm, 200mA, 120kV 2) Multi-detector computed tomography: slice thickness 0.75mm, 250mA, 120kV 3) Cone beam computed tomography: 15mAs, 120kV Axial images acquired from three computed tomographies were transferred to personal computer, and then reformatted cross-sectional images were generated using V-Implant $2.0^{(R)}$ (CyberMed Inc., Seoul, Korea) software. Among the cross-sectional images of the gutta perch a cone, placed in the buccal body of the mandible, the most precise cross section was selected as the measuring point and the distance from the most superior border of the mandibular canal to the alveolar crest was measured and analyzed 10 times by a dentist. Results: There were no significant intraobserver differences in the distance from the most superior border of the mandibular canal to the alveolar crest (p>0.05). There were no significant differences among single detector computed tomography, multi-detector computed tomography and cone beam computed tomography in the distance from the most superior border of the mandibular canal to the alveolar crest (p>0.05). Conclusion: Multi-detector computed tomography and cone beam computed tomography are clinically useful in the evaluation of pre-operative site for mandibular dental implants, with consideration for radiation exposure dose and scanning time.

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