• Title/Summary/Keyword: High- and low-dose-rate

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Survival and Complication Rate of Radiation Therapy in Stage I and II Carcinoma of Uterine Cervix (병기 I, II 자궁 경부암에서 방사선치료 후 생존율 및 합병증 분석)

  • Ma, Sun-Young;Cho, Heung-Lea;Sohn, Seung-Chang
    • Radiation Oncology Journal
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    • v.13 no.4
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    • pp.349-357
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    • 1995
  • Purpose : To analyze survival rate and late rectal and bladder complication for patients with stage I and II carcinoma of uterine cervix treated by radiation alone or combined with chemotherapy Materials and Methods : Between November 1984 and December 1993, 127 patients with stage I and II carcinoma of uterine cervix treated by radiation alone or combined therapy of radiation and chemotherapy. Retrospective analysis for survival rate was carried out on eligible 107 patients and review for complication was possible in 91 patients. The median follow-up was 47 months (range 3-118) and the median age of patiens was 56 years (range 31-76). 26 patients were stage IB by FIGO classification, 40 were stage IIA and 41 were stage IIB. 86 cases were treated by radiation alone and 21 were treated by radiation and chemotherapy. 101 patients were treated with intracavitary radiation therapy (ICRT), of these, 80 were received low dose rate (LDR) ICRT and 21 were received high dose rate (HDR) ICRT. Of the patients who received LDR ICRT, 63 were treated by 1 intracavitary insertion and 17 were underwent 2 insertions And we evaluated the external radiation dose and midline shield. Results : Actuarial survival rate at 5 years was $92{\%}$ for stage IB, $75{\%}$ for stage IIA, $53{\%}$ for stage IIB and $69{\%}$ in all patients Grade 1 rectal complications were developed in 20 cases ($22{\%}$), grade 2 were in 22 cases ($24{\%}$). 22 cases ($24{\%}$) of grade 1 urinary complications and 17 cases ($19{\%}$) of grade 2 urinary complications were observed But no patient had severe complications that needed surgical management or admission care. Maximum bladder dose for the group of patients with urinary complications was higher than that for the patients without urinary complications (7608 cGy v 6960cGy. p<0.01) Maximum rectal dose for the group of patients with rectal complications was higher than that for the patients without rectal complications (7041cGy v 6269cGy, p<0.01). While there was no significant difference for survival rate or bladder complication incidence as a function of dose to whole pelvis, Grade 2 rectal complication incidence was significantly lower for the patients receiving less than 4500cGy ($6.3{\%}$ v $25.5{\%}$, p<0.05). There was no significant differance between HDR ICRT group and LDR ICRT group for survival rate according to stage, on the other hand complication incidence was higher in the HDR group than LDR group, This was maybe due to different prescription doses between HDR group and LDR group. Midline shield neither improved survival rate nor decreased complication rate. The number of insertion in LDR ICRT group did not affect on survival and compication rate. Conclusion : In stage I and II carcinoma of uterine cervix there was no significant differance for 5 year survival rate by radiation therapy technique. Rectal complication incidence was as a function of dose to whole pelvis and there were positive correlations of maximum dose of rectum and bladder and each complication incidence. So we recommand whole pelvis dose less than 4500cGy and maximum dose of rectum and bladder as low as possible.

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Treatment of Clomiphene Citrate-Resistant Poly-Cystic Ovarian Syndrome (다낭성 난소질환의 치료에 관한 임상연구)

  • Song, Jung-Su;Kim, Eun-Im;Kim, Young-Min;Park, Yong-Suk;Hur, Kwang-Ok;Mok, Young-Ja
    • Clinical and Experimental Reproductive Medicine
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    • v.18 no.2
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    • pp.215-222
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    • 1991
  • Treatment with low-dose follicle-stimulating hormone and laparoscopic laser vaporization is associated with a high rate of ovulation in anovulatory women with polycystic ovarian syndrome (PCOS), but it is not clear which is better. We undertook a randomized controlled study to compare the effects of urinary FSH and hMG using a low dose regimen and laparoscopic laser vaporization of ovaries in sixty women with PCOS. Ovulation occured in 65% subjects and in 71.1% of cycles induced with FSH and in 70% of women and 76% of cycles of those treated with hMG and in 80% of women in laparoscopic laser vaporization of ovaries. A single dominant follicle developed in 62.2% (FSH) and 60% (hMG) of cycles, respectively. Eight singleton pregnancies occured in FSH, hMG group and 12 singleton pregnancies occured in laparoscopic laser vaporization. This study shows that selected patients with PCOS and by induced to ovulate and subsequently conceive by laparoscopically partially vaporizing their ovaries with laser energy.

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Reduced Effect of kV-CBCT Dose by Use of Shielding Materials in Radiation Therapy (방사선 치료 시 차폐물질 사용에 따른 kV-CBCT 선량감소 효과)

  • Jo, Hyeonjong;Park, Euntae;Kim, Junghoon
    • Journal of the Korean Society of Radiology
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    • v.12 no.4
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    • pp.467-474
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    • 2018
  • CBCT is useful for improving the accuracy of the treatment site, but Repeated use increases the exposure dose. In this study, we aimed to provide basic data for dose reduction in CBCT implementation by dataization the simulating and dose reduction effect using shielding substance. Material in this study, Analyzation the photon beam by simulate the CBCT Through MCNPX and then calculate the absorption dose of body organ at shooting moment of thoracic abdominal position as target UF-Revise simulated body. At this time. Dose reduction effects at this time were evaluated according to the texture of materials and presence of shielding materials( lead, antimony, barium, sulfate, tungsten, bismuth). When CBCT was taken without shielding, the dose was calculated to be high in the breast and spine, and the dose in the esophagus and lung was calculated to be low. The doses according to the shield material were calculated as barium sulfate, antimony, bismuth, lead, and tungsten. The shielding rate was the highest in the thymus (73.6%) and the breast (59.9%) compared with the dose reduction according to presence or absence of the shield. However, it showed the lowest shielding rate in lung (2.1%) and spine (12.6%).

Studies on the teratogenicity of folpet in the developing chick embryo (계태아를 이용한 농약(folpet)의 기형독성 연구)

  • Lim, Yoon-kyu;Heo, Gang-joon;Lee, Yong-soon
    • Korean Journal of Veterinary Research
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    • v.34 no.2
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    • pp.375-379
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    • 1994
  • A teratogenicity test of 'folpet' was carried out in the developing chick embryos to investigate and validate the safety of rural environmental hazardous materials. Folpet was administered to chick embryos' yolk sac at a rate of 0.1mg and 0.01mg per SPF eggs at 96 hours of incubation. The morphological changes were examined. Fertility ratio of SPF eggs used was 94.9%. Hatching rate of untreated control group was 74.4% and the group dosed with 100ul of corn oil into the yolk sac was 70.0%. The $LD_{50}$ of folpet was 0.663mg/100ul/egg. After hatching, mean body weight, body length, claw length and beak length of high and low dose administered groups were not significantly different from untreated and vehicle control group. There was no abnormal appearence in all the groups. Therefore it seems that, within the doses applied, folpet dose not induce potential teratogenicity in the developing chick embryos.

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Pooled Analysis of Pomalidomide for Treating Patients with Multiple Myeloma

  • Sun, Jia-Jia;Zhang, Chi;Zhou, Jun;Yang, Hui-Lin
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3163-3166
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    • 2015
  • Background: Patients with refractory or relapsed multiple myeloma are considered to have a very poor prognosis, and new regimens are needed to improve this setting. Pomalidomide is a new immunomodulatory drug with high in vitro potency. Immunomodulatory drugs are hypothesized to act through multiple mechanisms. Here we performed a systemic analysis to evaluate pomalidomide-based chemotherapy (pomalidomide in combination with low-dose dexamethasone) as salvage treatment for patients with refractory and relapsed multiple myeloma. Methods: Clinical studies evaluating the efffectiveness of pomalidomide based regimens on response and safety for patients with refractory and relapsed multiple myeloma were identified using a predefined search strategy. Pooled response rate (RR) of treatment were calculated. Results: For pomalidomide based regimens, 4 clinical studies which including 291 patients with refractory and relapsed multiple myeloma were considered eligible for inclusion. Systemic analysis suggested that, in all patients, pooled RR was 41.2% (120/291). Major adverse effects were hematologic toxicity, including grade 1 or 2 anemia, leucopenia and thrombocytopenia with pomalidomide based treatment. No treatment related death occurred. Conclusion: This pooled analysis suggests that pomalidomide in combination with low-dose dexamethasone is active with good tolerability in treating patients with refractory or relapsed multiple myeloma.

Preoperative Corticosteroid Use and Early Postoperative Bronchial Anastomotic Complications after Lung Transplantation

  • Kim, Ha Eun;Paik, Hyo Chae;Kim, Song Yee;Park, Moo Suk;Lee, Jin Gu
    • Journal of Chest Surgery
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    • v.51 no.6
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    • pp.384-389
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    • 2018
  • Background: Airway anastomotic complications are a leading cause of mortality after lung transplantation. Among the factors that cause airway complications, preoperative steroid use has been considered to be related with postoperative airway healing. We analyzed the influence of preoperative steroid use on postoperative airway complications. Methods: The medical records of 66 double-lung transplant recipients from January 2014 to December 2015 were reviewed. Forty patients were prescribed steroids preoperatively. The daily steroid dose was standardized using the patient's body mass index (BMI). Patients who received preoperative steroids were sub-divided into high-dose (HD) and low-dose (LD) groups (cut-off value, 1.6 mg/BMI/day). Results: Thirteen patients suffered from airway complications postoperatively (bronchopulmonary fistula, 9; bronchial stenosis, 4). There was a tendency for early development of airway complications in the steroid use group compared to the non-steroid use group, but it was not significant (percentage free from airway complications in year 1: non-steroid group, 90.9% vs. steroid group, 79.2%; p=0.43). The percentage of patients in the LD and HD groups who were free from airway complications in year 1 was not significantly different (84.0% vs. 77.8%, p=0.39). Conclusion: The airway complication rate did not vary significantly according to steroid use. Additionally, in patients who received preoperative steroids, the dose did not affect the rate of development of airway complications.

The Clinical Usefulness Evaluation of Normal Saline Injection in Coronary Artery Computed Tomography Angiography(Coronary CTA) (관상동맥 전산화단층촬영 조영검사에서 생리식염수 투여를 통한 임상 유용성 평가)

  • Jung, Kang-Kyo;Lee, Mi-Hwa;Cho, Pyong-Kon
    • Journal of radiological science and technology
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    • v.37 no.4
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    • pp.307-313
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    • 2014
  • The purpose of this study is that in coronary artery angiography computed tomography (coronary CTA), to gain high quality of image and to use low dose radiation by administrating normal saline and converting the mode of scanning heart rate (HR) characteristics before infusing contrast media. All patients data (total specimens: 200, male: 108, female: 92) were measured by using appropriate mode of scanning the heart rate (HR) after injection of saline. in addition we measured radiation dose (CTDIvol, effective dose) in all examinations. CT number and noise, and blurring of coronary artery (proximal RCA, middle RCA, proximal LCA) were measured and compared. The result of this study after injection of saline, mean heart rate was decreased about $4.8{\pm}0.3bpm$ (beats per minute). 33 patients (13%) got converting scan mode due to reducing heart rate (HR). In prospective gating mode, radiation dose were measured less $6.0{\pm}1.0mSv$ (54.1%) than retrospective gating mode. Also showed a significant difference in heart rate decrease in image evaluation.

DL-RRT* algorithm for least dose path Re-planning in dynamic radioactive environments

  • Chao, Nan;Liu, Yong-kuo;Xia, Hong;Peng, Min-jun;Ayodeji, Abiodun
    • Nuclear Engineering and Technology
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    • v.51 no.3
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    • pp.825-836
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    • 2019
  • One of the most challenging safety precautions for workers in dynamic, radioactive environments is avoiding radiation sources and sustaining low exposure. This paper presents a sampling-based algorithm, DL-RRT*, for minimum dose walk-path re-planning in radioactive environments, expedient for occupational workers in nuclear facilities to avoid unnecessary radiation exposure. The method combines the principle of random tree star ($RRT^*$) and $D^*$ Lite, and uses the expansion strength of grid search strategy from $D^*$ Lite to quickly find a high-quality initial path to accelerate convergence rate in $RRT^*$. The algorithm inherits probabilistic completeness and asymptotic optimality from $RRT^*$ to refine the existing paths continually by sampling the search-graph obtained from the grid search process. It can not only be applied to continuous cost spaces, but also make full use of the last planning information to avoid global re-planning, so as to improve the efficiency of path planning in frequently changing environments. The effectiveness and superiority of the proposed method was verified by simulating radiation field under varying obstacles and radioactive environments, and the results were compared with $RRT^*$ algorithm output.

Application of Commercial PIN Photodiodes to develope Gamma-Ray Dosimeters (감마선 선량계를 개발하기 위한 상용 PIN 포토 다이오드의 응용)

  • Jeong, Dong-Hwa;Kim, Sung-Duck
    • Journal of Sensor Science and Technology
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    • v.9 no.4
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    • pp.274-280
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    • 2000
  • This paper deals with an experimental study to apply commercial semiconductors to measure radiation dose rate for gamma ray. Since the low cost, small size, high efficiency and ruggedness of silicon photodiodes make them attractive photodetectors, they coulde be effectively used in measuring any radiation such as gamma ray. Most PN photodiodes show that the reverse current increases when the light is increased. Therefore the depletion region of them have influence on the reverse current, so we choose silicon PIN photodiodes with large depletion region. In order to detect radiation dose rate and then, to apply in developing any gamma ray dosimeter, some examinations and experiments were performed to PIN photodiodes in this work. Two kinds of PIN photodiodes, such as NEC's PH302 and SIEMENS's BPW34, were tested in a Co-60 gamma irradiation facility with a semiconductor parameter analyzer. As a result, we found that such PIN photodiodes present good linearity in diode current characteristics with dose rate. Therefore silicon PIN photodiodes could be suitably used in designing gamma ray dosimeters.

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The Effect of Steroid Therapy for Idiopathic Unilateral Vocal Cord Palsy (특발성 일측성 성대마비에서 경구 스테로이드 요법의 효과)

  • Bae, Jong-Won;Lee, GilJoon
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.30 no.2
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    • pp.107-111
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    • 2019
  • Background and Objectives Idiopathic unilateral vocal fold paralysis (IVFP) is believed to be due to inflammation and edema of the recurrent laryngeal nerve caused by viral diseases such as upper respiratory tract infections. Corticosteroid has a potent anti-inflammatory action which should minimize nerve damage. The purpose of this study was to investigate the effect of oral steroid therapy on IVFP. Materials and Method Study was performed for the IVFP patient from January 2012 to August 2017. Patient's dermography, direction and location of paralyzed vocal cords, history of hypertension, diabetes, cerebrovascular disease, and other underlying disease, smoking history, alcohol consumption and upper respiratory tract infection, and symptoms were investigated. Treatment was divided into three groups: the observation group, low-dose group, and high-dose group, and the recovery rate and time of vocal cord paralysis were analyzed in each group. Results Thirty-seven patients were enrolled in this study. There was no relationship between oral steroid use, dosage and recovery of vocal cord paralysis. Oral steroids showed a rapid recovery of vocal cord paralysis, but there was no statistically significant difference in the time of recovery of vocal palsy with or without steroids (p=0.673). In addition, there was no statistically significant difference in recovery rate between the period to start of treatment, presence of diabetes mellitus, and treatment modality, but the recovery rate was high in the group with upper respiratory tract infection history (p=0.041). Conclusion In IVFP, oral steroid therapy has no significant difference in time and extent of recovery compared to the case of spontaneous recovery.