• Title/Summary/Keyword: half-dose

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Evaluation of Dose Variation according to Air Gap in Thermoplastic Immobilization Device in Carbon Ion (탄소입자 치료 시 열가소성 고정기구의 공기층에 따른 선량 변화 평가)

  • Ye-jin Na;Ji-Won Jang;Se-Wuk Jang;Hyo-Kuk Park;Sang-Kyu Lee
    • The Journal of Korean Society for Radiation Therapy
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    • v.35
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    • pp.33-39
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    • 2023
  • Purpose: The purpose of this study is to find out the dose variation according to thickness of the air gap between the patient's body surface and immobilization device in the treatment plan. Materials and Methods : Four conditions were created by adjusting the air gap thickness using 5 mm bolus, ranging from 0 mm to 3 mm bolus. Immobilization was placed on top in each case. And computed tomography was used to acquire images. The treatment plan that 430 cGy (Relative Biological Effectiveness,RBE) is irradiated 6 times and the dose of 2580 cGy (RBE) is delivered to 95% of Clinical Target Volume (CTV). The dose on CTV was evaluated by Full Width Half Maximum (FWHM) of the lateral dose profile and skin dose was evaluated by Dose Volume Histogram (DVH). Result: Results showed that the FWHM values of the lateral dose profile of CTV were 4.89, 4.86, 5.10, and 5.10 cm. The differences in average values at the on the four conditions were 3.25±1.7 cGy (RBE) among D95% and 1193.5±10.2 cGy (RBE) among D95% respectively. The average skin volume at 1% of the prescription dose was 83.22±4.8%, with no significant differences in both CTV and skin. Conclusion: When creating a solid-type immobilization device for carbon particle therapy, a slight air gap is recommended to ensure that it does not extend beyond the dose application range of the CTV.

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A study on the Gypsum and Natrii sulfas dose of 1 day and 1 time in Shanhanlun and Gumgyeyoryak (상한론(傷寒論)과 금궤요략(金櫃要略)에서 석고(石膏)와 망초(芒硝) 1일 용량과 1회 용량)

  • Jeon, Sae-Hun;Kim, In-Rak
    • The Korea Journal of Herbology
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    • v.22 no.4
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    • pp.45-50
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    • 2007
  • Objectives : The purpose of this study is to determine dose of Gypsum and Natrii sulfas in Shanhanlun and Geumgyeyoryak Methods : We measured the egg size Gypsum, and Natrii sulfas 1 Seong(升), and Results : 1. The weight of GYPSUM, egg is about $48{\pm}4g$, it will end up with 104g, when applying egg gravity of 1.055 and Gypsumls weight of 2.3. 2. One Ryang(兩) is equal to 6.5g in Sanghanlun and Gumgyeyoryak, and therefore the weight of ones gypsum is equal to 1 Keun(斤). 3. Compare to a dose of Gypsum is equal to one egg in Mokbanggitang. 4. Maximum dosage of Gypsum is equal to half an egg, 8Ryang(兩) of Sanghanlun, which is 52g. 5. Daily dosage of One Keun(斤) of Natrii sulfas is 8 Ryang(兩), of sanghanlun, which is 52g, Maximum dosage of Sanghanlun is 4 Ryang(兩), which is 26g. Conclusion : As stated above we may acknowledge that a dosage of Gypsum and Narii sulfas in either Sanghanlun and Keumgyeyoryak is applicable range in practical clinic.

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Appropriate Time for Primaquine Treatment to Reduce Plasmodium falciparum Transmission in Hypoendemic Areas

  • Wilairatana, Polrat;Krudsood, Srivicha;Tangpukdee, Noppadon
    • Parasites, Hosts and Diseases
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    • v.48 no.2
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    • pp.179-182
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    • 2010
  • Artemesinin-combination therapies (ACT) for falciparum malaria reduce gametocyte carriage, and therefore reduce transmission. Artemisinin derivatives will act against only young gametocytes whereas primaquine acts on mature gametocytes which are present usually in the circulation at the time when the patient presents for treatment. Both artemisinin derivatives and primaquine have short half-lives, less than 1 hr and 7 hr, respectively. Therefore, asexual parasites or young gametocytes remain after completed ACT. A single dose of primaquine (0.50-0.75 mg base/kg) at the end of ACT can kill only mature gametocytes but cannot kill young gametocytes (if present). Remaining asexual forms after completion of ACT course, e.g., artesunate-mefloquine for 3 days, may develop to mature gametocytes 7-15 days later. Thus, an additional dose of primaquine (0.50-0.75 mg base/kg) given 2 weeks after ACT completion may be beneficial for killing remaining mature gametocytes and contribute to more interruption of Plasmodium falciparum transmission than giving only 1 single dose of primaquine just after completing ACT.

Evaluation of Radiolucent Considering the Compression Paddle Materials in Mammography (유방촬영장치의 압박대 재질을 고려한 투과선량 평가)

  • Hong, Dong-Hee
    • The Journal of the Korea Contents Association
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    • v.15 no.11
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    • pp.307-312
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    • 2015
  • Mammography improves image quality that is on the increase day by day and get a picture with the pressure it is essential to reduce the dose. However, because due to the thickness of the cuff itself may increase the dose scattering lines is necessary study on the cuff material. Material that is currently being used in clinical Polycarbonate is a plastic and family. If you try to reduce the exposure of patients than itgie need to consider for the better material in this study to compare against a radiolucent line for amorphous plastic material of the plastic. results radiolucent and half layer, transmitting dose Pixel values HIPS, GPPS, ABS, Tritan, PC, PMMA showed high results in the net.

Control of the cigarette beetle, Losiodeyma senieorne F., in warehouse by pirimiphos - methyl fogging (Pirimiphos-methyl 연무처리에 의한 원료창고내 궐련벌레 (Lasioderma serricorne F.) 방제에 관한 연구)

  • 오명희;박규택
    • Journal of the Korean Society of Tobacco Science
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    • v.15 no.2
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    • pp.167-173
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    • 1993
  • Pirimiphos - methyl was fogged in a tobacco warehouse to determine the proper dose rate, Small wire cages, containing adults and larvae of cigarette beetle (Lasiodema senicorne F.) were put at different altitude in the warehouse of which the holding capacity was about 250m3. At recommended dose rate, 0.4ml/m3(25% ai), it brought about 100% mortality of adults and 98.8% -100% mortality of larvae. When the dose rate was reduced to about half the recommended one, 97.6 and 96.4% mortality could still be obtained against adults and larvae, respectively. The number of the beetles monitored by sex - pheromone trap was greatly reduced after the fogging in the warehouses at 4 geographic places in Korea. When the warehouses were ventilated for one hour immediately after the fogging done for 48 hours, workers could not detected any opposing smell in the warehouses. And panel members responded positively that there was no negative effect on the taste of the cigarettes made of the fogged tobacco. Although the residue of the chemical was detected from the cigarettes in 4 of 5 cases, the residue was 1.1-1.3$\mu\textrm{g}$/20 cigarettes except for one case from which 3.3$\mu\textrm{g}$/20 cigarettes residue was detected. The relatively low residue is about l/450-1/150 of the WHO/FAO tolerant level.

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Treatment of high-risk neuroblastoma

  • Sung, Ki-Woong
    • Clinical and Experimental Pediatrics
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    • v.55 no.4
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    • pp.115-120
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    • 2012
  • Although high-dose chemotherapy and autologous stem cell transplantation (HDCT/autoSCT) have improved the prognosis for patients with high-risk neuroblastoma (NB), event-free survival rates remain in the range of 30 to 40%, which is unsatisfactory. To further improve outcomes, several clinical trials, including tandem HDCT/autoSCT, high-dose $^{131}I$-metaiodobenzylguanidine treatment, and immunotherapy with NB specific antibody, have been undertaken and pilot studies have reported encouraging results. Nonetheless, about half of high-risk NB patients still experience treatment failure and have no realistic chance for cure with conventional treatment options alone after relapse. Therefore, a new modality of treatment is warranted for these patients. In recent years, several groups of investigators have examined the feasibility and effectiveness of reduced-intensity allogeneic stem cell transplantation (RI alloSCT) for the treatment of relapsed/progressed NB. Although a graft-versus-tumor effect has not yet been convincingly demonstrated in the setting of relapsed NB, the strategy of employing RI alloSCT has provided hope that treatment-related mortality will be reduced and a therapeutic benefit will emerge. However, alloSCT for NB is still investigational and there remain many issues to be elucidated in many areas. At present, alloSCT is reserved for specific clinical trials testing the immunomodulatory effect against NB.

Effect of Renal Failure on Pharmacokinetics of Carbamazepine in Rabbits (카르바마제핀의 체내동태에 대한 신장해의 영향)

  • Lee, Chong Ki;Park, Hyun Jin;Cho, Heng Nam
    • Korean Journal of Clinical Pharmacy
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    • v.9 no.2
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    • pp.92-96
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    • 1999
  • The pharmacokinetics of carbamazepine(100 mg/kg, oral) in the folic acid-induced renal failure rabbits was studied. Renal failure was induced by the i.v. injection of folic acid (50, 100, and 200 mg/kg). At folic acid dose of 100 and 200 mg/kg, the serum creatinine concentration (Scr) and blood urea nitrogen (BUN) increased significantly compared with control rabbits. Plasma concentrations and area under the plasma level-time curve (AUC) of carbamazepine increased significantly at folic acid dose of 100 and 200 mg/kg. The elimination rate constant (Kel) of carbamazepine decreased significantly, and half-life $(t_{1/2})$ of carbamazepine increased significantly at folic acid dose of 100 and 200 mg/kg. The serum creatinine concentration (Scr) correlated well with AUC and elimination rate constant (Kel) of carbamazepine, as well as BUN with AUC and elimination rate constant (Kel) of carbamazepine. These results suggest that adjustment of the dosage regimen of carbamazepine is desirable, and serum creatinine concentration (Scr) as well as BUN can be used for adjusting the dosage regimen of carbamazepine in renal failure.

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High Dose Rate Ir-192 Source Calibration Method with Newly Designed Calibration Jig (고선량 Ir-192선원 교정기의 제작 및 특성)

  • Yi, Byong-Yong;Choi, Eun-Kyung;Chang, Hye-Sook
    • Radiation Oncology Journal
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    • v.7 no.2
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    • pp.299-303
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    • 1989
  • Authors have developed highly reproducible calibration method for the Micro-Selectron HDR Ir-192 system (Nucletron, Motherland). The new jig has a 10cm radius circular hole in the $30cm{\times}30cm{\times}0.2cm$ acrylic plate, and 5F flexible bronchial tubes are attached around the hole. The source moves along the circle in the tubes and the ionization chamber is placed verticaly at the center of the circular hole (center of the jig). Dose distribution near the center was derived theoretically, and measured with the film dosimetry system. Theoretical calculation and measurement show the error margin below $0.1\%$ for 1mm or 2mm position deviation. We have measured at 12 and 24 points of circle with 1, 6, 11 and 21 second dwell time of source in order to calculate the activity of the source. Measurements have been repeated daily for 50 days. The accuracy and the reproducibility are below $1\%$ error margin. The half life of the source from our measurement is estimated $73.4\pm0.4$ days.

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Sedation with dexmedetomidine in elderly patients during dental surgery: a retrospective case series

  • Seto, Mika;Kita, Ryosuke;Kondo, Seiji
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.45 no.3
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    • pp.152-157
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    • 2019
  • Objectives: The number of elderly patients with systemic basal disease requiring invasive dental treatment has increased. Appropriate prediction of surgical invasiveness and combined use of psychosedation are thought to contribute to safe whole-body management. Dexmedetomidine (DEX) exhibits analgesic and anti-anxiolytic properties and causes mild respiratory depression. Studies regarding DEX use in elderly non-intubated patients are scarce. We aimed to use retrospective data to determine an effective dose of DEX to induce adequate sedation in elderly patients undergoing invasive dental surgery under local anesthesia. Materials and Methods: One hundred two patients aged 70 to 96 years were presumably appropriately controlled with sedation. DEX was administered at an initial loading dose of 2.0 to $3.1{\mu}g/kg/hr$ for 10 minutes. We divided the patients into five groups by age and compared their blood pressures and heart rates. Results: In all five groups, blood pressure decreased suddenly at approximately 15 and 20 minutes after DEX administration. A marked decrease in blood pressure was noted in patients aged 75 to 79 years. Conclusion: For elderly patients aged 75 years and above, the initial loading dose of DEX needs to be reduced to lower than half that required for young and middle-age adults.

Dose Rate of Restroom in Facilities using Radioisotope (방사성동위원소 사용시설(내/외) 화장실의 외부선량률)

  • Cho, Yong-Gwi;An, Seong-Min
    • Journal of radiological science and technology
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    • v.39 no.2
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    • pp.237-246
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    • 2016
  • This study is therefore aimed at measuring the surface dose rate and the spatial dose rate in and outside the radionuclide facility in order to ensure safety of the patients, radiation workers and family care-givers in their use of such equipment and to provide a basic framework for further research on radiation protection. The study was conducted at 4 restrooms in and outside the radionuclide facility of a general hospital in Incheon between May 1 and July 31, 2014. During the study period, the spatial contamination dose rate and the surface contamination dose rate before and after radiation use were measured at the 4 places-thyroid therapy room, PET center, gamma camera room, and outpatient department. According to the restroom use survey by hospitals, restrooms in the radionuclide facility were used not only by patients but also by family care-givers and some of radiation workers. The highest cumulative spatial radiation dose rate was 8.86 mSv/hr at camera room restroom, followed by 7.31 mSv/hr at radioactive iodine therapy room restroom, 2.29 mSv/hr at PET center restroom, and 0.26 mSv/hr at outpatient department restroom, respectively. The surface radiation dose rate measured before and after radiation use was the highest at toilets, which are in direct contact with patient's excretion, followed by the center and the entrance of restrooms. Unsealed radioactive sources used in nuclear medicine are relatively safe due to short half lives and low energy. A patient who received those radioactive sources, however, may become a mobile radioactive source and contaminate areas the patient contacts-camera room, sedation room, and restroom-through secretion and excretion. Therefore, patients administered radionuclides should be advised to drink sufficient amounts of water to efficiently minimize radiation exposure to others by reducing the biological half-life, and members of the public-family care-givers, pregnant women, and children-be as far away from the patients until the dose remains below the permitted dose limit.