• 제목/요약/키워드: Effective Dose Rate

검색결과 514건 처리시간 0.024초

Reduced-dose whole-brain radiotherapy with tumor bed boost after upfront high-dose methotrexate for primary central nervous system lymphoma

  • Lee, Tae Hoon;Lee, Joo Ho;Chang, Ji Hyun;Ye, Sung-Joon;Kim, Tae Min;Park, Chul-Kee;Kim, Il Han;Kim, Byoung Hyuck;Wee, Chan Woo
    • Radiation Oncology Journal
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    • 제38권1호
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    • pp.35-43
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    • 2020
  • Purpose: This retrospective study compares higher-dose whole-brain radiotherapy (hdWBRT) with reduced-dose WBRT (rdWBRT) in terms of clinical efficacy and toxicity profile in patients treated for primary central nervous system lymphoma (PCNSL). Materials and Methods: Radiotherapy followed by high-dose methotrexate (HD-MTX)-based chemotherapy was administered to immunocompetent patients with histologically confirmed PCNSL between 2000 and 2016. Response to chemotherapy was taken into account when prescribing the radiation dose to the whole brain and primary tumor bed. The whole brain dose was ≤23.4 Gy for rdWBRT (n = 20) and >23.4 Gy for hdWBRT (n = 68). Patients manifesting cognitive disturbance, memory impairment and dysarthria were considered to have neurotoxicity. A median follow-up was 3.62 years. Results: The 3-year overall survival (OS) and progression-free survival (PFS) were 70.0% and 48.9% with rdWBRT, and 63.2% and 43.2% with hdWBRT. The 3-year OS and PFS among patients with partial response (n = 45) after chemotherapy were 77.8% and 53.3% with rdWBRT, and 58.3% and 45.8% with hdWBRT (p > 0.05). Among patients with complete response achieved during follow-up, the 3-year freedom from neurotoxicity (FFNT) rate was 94.1% with rdWBRT and 62.4% with hdWBRT. Among patients aged ≥60 years, the 3-year FFNT rate was 87.5% with rdWBRT and 39.1% with hdWBRT (p = 0.49). Neurotoxicity was not observed after rdWBRT in patients aged below 60 years. Conclusion: rdWBRT with tumor bed boost combined with upfront HD-MTX is less neurotoxic and results in effective survival as higher-dose radiotherapy even in partial response after chemotherapy.

강황 에탄올 추출물 및 그 분획물의 초산 유발에 의한 통증억제 효과 (Anti-nociceptive Effect of Curcuma longa Extract on Acetic Acid induced Pain Model)

  • 윤원호;이경호
    • 생약학회지
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    • 제46권3호
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    • pp.229-233
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    • 2015
  • The anti-nociceptive effect of an ethanol extract and its various solvent fractions from Curcuma longa Linne ethanol extract was studied using the writhing test in mice. Different fractions by various solvent extraction from Curcuma longa Linne ethanol extract were administered orally 1 hr or time-course (0.5, 1, 2 and 5 hr) before intraperitoneal injection of acetic acid. After treatment with 30% ethanol extract and n-butanol fraction, CB-1, at a dose of 250 mg/kg, the significant writhing responses were 87.5 ± 13.4 (inhibition rate 31%, p<0.01) and 75.1 ± 11.1 (inhibition rate 41%, p<0.01) lower than the control group. At the dose of CB-1 50 mg/kg and 250 mg/kg, CB-1 showed a similar activity comparing to diclofenac of 10 mg/kg. A time-course experiment was performed, which involved oral administration of CB-1 (250 mg/kg) at 0, 0.5, 1, 2, and 5 hr before acetic acid intraperitoneal injection. The most effective time of CB-1 was 30 min before treatment and persisting until 2 hr. This study showed that Curcuma longa Linne has anti-nociceptive properties comparable with those of diclofenac, which suggests promise for the treatment of intractable visceral pain in humans. Major components of the active fraction are identified as curcumin, cyclocurcumin and demethoxycurcumin.

鹽基相似體를 前處理한 HeLa $S_3$ 細胞에 있어 Bleomycin에 의한 DNA 回復合成 (DNA Repair Synthesis Induced by Bleomycin in HeLa $S_3$ Cells Pretreated with Base Analogs)

  • Um, Kyung-Il;Park, Sang-Dai
    • 한국동물학회지
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    • 제20권1호
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    • pp.41-48
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    • 1977
  • Bleomycin에 의해 유발된 DNA 회복합성은 저농도 처리군에서는 농도의 증가에 따라 증가하며 $5\\mu$g/ml 군에서 조사한 전세포의 15%가 회복합성을 하여 최고율을 보인다. 고농도 처리군에서 DNA 회복합성율이 감소하며 처리 시간을 연장해도 그율은 변화가 없다. BUdR이나 IUdR을 전처리한군에서는 DNA회복합성을 증가시키는 것으로 판명됐으며 또한 고동도 처리군에서는 정상적인 DNA 합성을 억제한다. 시간 변화에 따른 실험에서는 처리한 bleomycin을 제거한후 24시간까지 DNA 회복합성이 계속됐다. 이들 결과는 bleomycin이 excision repair를 유발하는 효과적인 화학물질이 아니며, bleomycin에 의해 유발되는 DNA의 손상은 DNA 나선 절단뿐만 아니라 다른 형태의 DNA 손상도 유발함을 추측할수 있다.

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오미자 추출물이 산소지유기에 의하여 손상된 생쥐의 배양 심근세포에 미치는 영향 (Effects of Fructus Schisandrae Water Extract on Cultured Mouse Myocardial Cells Induced by Xanthine Oxidase/Hypoxanthine)

  • 주은정
    • Journal of Nutrition and Health
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    • 제33권7호
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    • pp.739-744
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    • 2000
  • The purpose of this study was to elucidate protective effect of Fructus Schsandrae(FS) water extract against xanthine oxidase/hypoxanthine(XO/HX)-induced cardiotoxicity in myocardial cells this experiment was performed. Cardiotoxicity of XO/HX was examined by MTT(MTT [3-(4,5-dimethylthiazol-2-yl)-2.5,-diphenyl tetrazolium bromide) assay. XO/HX induced the decrease of cell viability. Also XO/HX induced the increase of LDH activity and the decrease of beating rate on cultured myocardial cells in a dose-dependent manner. To investigate cardioprotective effect of FS water extract cultures were preincubated with FS water extract for 3 hours. Cultures were then exposed to XO/HX for 72 hours. FS water extract have an efficacy in decreaasing LDH activity and increasing heart beating rate on cultured myocardial cells damaged by XO/HX. From the results it is suggested that XO/HX may show toxic effect in cultured myocardial cells derived from neonatal mouse and FS water extract is effective in the prevention of XO/HX-induced cardiotoxicity.

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고체 촉매를 이용한 대두유와 폐식용유의 에스테르화 (Esterification of the Soybean Oil and Waste Vegetable Oil by Solid Catalysts)

  • 신용섭
    • 한국환경과학회지
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    • 제13권1호
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    • pp.79-87
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    • 2004
  • Esterification of soybean oil with methanol was investigated. First of all, liquid-liquid equilibriums for systems of soybean oil and methanol were measured at temperatures ranging from 40 to 65$^{\circ}C$. Profiles of conversion of soybean oil with time were determined from the glycerine content in reaction mixtures for the different kinds of catalysts, such as NaOH, CaO, Ca(OH)$_2$, MgO, Mg(OH)$_2$, and Ba(OH)$_2$. The effects of dose of catalyst, cosolvent and reaction temperature on final conversion were examined. Esterification of waste vegetable oil with methanol was investigated and compared to the case of soybean oil. Solubility of methanol in soybean oil was substantially greater than that of soybean oil in methanol. When the esterification reaction of soybean oil was catalyzed by solid catalyst, final conversion was strongly dependent on the alkalinity of the solid catalyst, and increased with the alkalinity of the metal. Hydroxides from the alkali metals were more effective than oxides. When Ca(OH)$_2$ was used for the esterification catalyst, maximum value of final conversion was measured at dose of 4%. When CHCl$_3$ as a cosolvent, was added into the reaction mixture of soybean oil which catalyzed by Ba(OH)$_2$, maximum value of final conversion was appeared at dose of 3%. When waste vegetable oil was catalyzed by NaOH and solid catalysts, high final conversion, over 90%, and fast reaction rate were obtained.

Effectiveness of emergency contraception in women after sexual assault

  • Choi, Dong Seok;Kim, Miran;Hwang, Kyung Joo;Lee, Kyoung Mi;Kong, Tae Wook
    • Clinical and Experimental Reproductive Medicine
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    • 제40권3호
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    • pp.126-130
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    • 2013
  • Objective: To assess the effectiveness of emergency single-dose levonorgestrel contraception in preventing unintended pregnancies among woman who visited the emergency department (ED) due to sexual assault (SA). Methods: We conducted a retrospective chart review in a university hospital in South Korea. Cases from November 10, 2006 to November 9, 2009 were enrolled. Information from the initial visit to the ED and subsequent follow-up visits to the gynecology outpatient clinic was collected. Results: In total, 1,179 women visited the ED due to SA. Among them, 416 patients had a gynecological examination and 302 patients who received emergency contraception (EC) (1.5 mg single-dose levonorgestrel) at the ED due to SA were enrolled. Ten patients did not return for follow-up examinations. In follow-up visits at the outpatient clinic, two pregnancies were confirmed, which showed the failure rate of the EC to be 0.68%. Conclusion: Single-dose levonorgestrel EC is extremely effective at preventing pregnancy among victims of SA.

Brachytherapy: A Comprehensive Review

  • Lim, Young Kyung;Kim, Dohyeon
    • 한국의학물리학회지:의학물리
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    • 제32권2호
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    • pp.25-39
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    • 2021
  • Brachytherapy, along with external beam radiation therapy (EBRT), is an essential and effective radiation treatment process. In brachytherapy, in contrast to EBRT, the radiation source is radioisotopes. Because these isotopes can be positioned inside or near the tumor, it is possible to protect other organs around the tumor while delivering an extremely high-dose of treatment to the tumor. Brachytherapy has a long history of more than 100 years. In the early 1900s, the radioisotopes used for brachytherapy were only radium or radon isotopes extracted from nature. Over time, however, various radioisotopes have been artificially produced. As radioisotopes have high radioactivity and miniature size, the application of brachytherapy has expanded to high-dose-rate brachytherapy. Recently, advanced treatment techniques used in EBRT, such as image guidance and intensity modulation techniques, have been applied to brachytherapy. Three-dimensional images, such as ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography are used for accurate delineation of treatment targets and normal organs. Intensity-modulated brachytherapy is anticipated to be performed in the near future, and it is anticipated that the treatment outcomes of applicable cancers will be greatly improved by this treatment's excellent dose delivery characteristics.

Assessment of occupational radiation exposure of NORM scales residues from oil and gas production

  • EL Hadji Mamadou Fall;Abderrazak Nechaf;Modou Niang;Nadia Rabia;Fatou Ndoye;Ndeye Arame Boye Faye
    • Nuclear Engineering and Technology
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    • 제55권5호
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    • pp.1757-1762
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    • 2023
  • Radiological hazards from external exposure of naturally occurring radioactive materials (NORM) scales residues, generated during the extraction process of oil and gas production in southern Algeria, are evaluated. The activity concentrations of 226Ra, 232Th, and 40K were measured using high-purity gamma-ray spectrometry (GeHP). Mean activity concentration of 226Ra, 232Th and 40K, found in scale samples are 4082 ± 41, 1060 ± 38 and 568 ± 36 Bq kg-1, respectively. Radiological hazard parameters, such as radium equivalent (Raeq), external and internal hazard indices (Hex, Hin), and gamma index (Iγ) are also evaluated. All hazard parameter values were greater than the permissible and recommended limits and the average annual effective dose value exceeded the dose constraint (0.3 mSv y-1). However, for occasionally exposed workers, the dose rate of 0.65 ± 0.02 mSv y-1 is lower than recommended limit of 1 mSv y-1 for public.

증발을 이용한 방사성 액체폐기물의 처리와 피폭선량평가 (Treatment of Radioactive Liquid Waste Using Natural Evaporator and Resulted Exposure Dose Assessment)

  • 정경환;박승국;김은한;정기정;박현수
    • Journal of Radiation Protection and Research
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    • 제24권2호
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    • pp.101-108
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    • 1999
  • 극저준위 방사성액체폐기물 처리를 위하여 공기의 온도와 습도 및 유입 공기의 속도에 따른 증발량의 관계를 천을 이용한 강제증발실험 장치로 실험하였다. 그 결과 각각의 변수와 증발량의 상관관계를 실험식으로 도출하였다. 또한 Cs-137 을 함유한 모의폐액을 사용하여 본 장치에 대한 제염 계수를 얻은 결과 $DF=10^4$으로 나타났다. TRlGA Mark II & III 연구용 원자로 폐로시 발생되는 극저준위 방사성액체폐기물을 증발장치로 처리할 때 주변의 일반개인에 대한 연간 피폭선량을 보수적으로 평가한 결과, 유효선량 (effective dose)은 $1.01{\times}10^{-3}mSv$이고, 환경으로 배출되는 공기의 방사능 농도(Cs-137)는 $4.637{\times}10^{-14}\;{\mu}Ci/cc$ air 이다. 따라서 극저준위 방사성액체폐기물의 처리를 위하여 강제증발장치를 사용하는 것은 주민에 아무런 영향이 없음을 알 수 있었다.

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Impact of Treatment Time on Chemoradiotherapy in Locally Advanced Cervical Carcinoma

  • Pathy, Sushmita;Kumar, Lalit;Pandey, Ravindra Mohan;Upadhyay, Ashish;Roy, Soumyajit;Dadhwal, Vatsla;Madan, Renu;Chander, Subhash
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권12호
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    • pp.5075-5079
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    • 2015
  • Background: Adverse effects of treatment prolongation beyond 8 weeks with radiotherapy for cervical cancer have been established. Clinical data also show that cisplatin increases the biologically effective dose of radiotherapy. However, there are no data on the effect of overall treatment time in patients with locally advanced cervical cancer treated with concomitant chemo-radiotherapy (CCRT) in an Indian population. The present study concerned the feasibility of concurrent chemotherapy and interspacing brachytherapy during the course of external radiotherapy to reduce the overall treatment time and compare the normal tissue toxicity and loco-regional control with a conventional schedule. Materials and Methods: Between January 2009 and March 2012 fifty patients registered in the Gynaecologic Oncology Clinic of Institute Rotary Cancer Hospital with locally advanced cervical cancer (FIGO stage IIB-IIIB) were enrolled. The patients were randomly allocated to treatment arms based on a computer generated random number. Arm I (n=25) treatment consisted of irradiation of the whole pelvis to a dose of 50 Gy in 27 fractions, and weekly cisplatin $40mg/m^2$. High dose rate intra-cavitary brachytherapy (HDR-ICBT) was performed after one week of completion of external beam radiotherapy (EBRT). The prescribed dose for each session was 7Gy to point A for three insertions at one week intervals. Arm II (n=25) treatment consisted of irradiation of the whole pelvis to a dose of 50 Gy in 27 fractions. Mention HDR-ICBT ICRT was performed after 40Gy and 7Gy was delivered to point A for three insertions (days 23, 30, 37) at one week intervals. Cisplatin $20mg/m^2/day$ was administered from D1-5 and D24-28. Overall treatment time was taken from first day of EBRT to last day of HDR brachytherapy. The overall loco-regional response rate (ORR) was determined at 3 and 6 months. Results: A total of 46 patients completed the planned treatment. The overall treatment times in arm I and arm II were $65{\pm}12$ and $48{\pm}4$ days, respectively (p=0.001). At three and six months of follow-up the ORR for arm I was 96% while that for arm II was 88%. No statistically significant difference was apparent between the two arms. The overall rate of grade ${\geq}3$ toxicity was numerically higher in arm I (n=7) than in arm II (n=4) though statistical significance was not reached. None of the predefined prognostic factors like age, performance status, baseline haemoglobin level, tumour size, lymph node involvement, stage or histopathological subtype showed any impact on outcome. Conclusions: In the setting of concurrent chemoradiotherapy a shorter treatment schedule of 48 days may be feasible by interspacing brachytherapy during external irradiation. The response rates and toxicities were comparable.