• Title/Summary/Keyword: k-dose

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Selection of radiation treatment plan technique at breast cancer operating technique (유방암 수술기법에 따른 방사선치료계획 기법의 선택)

  • Kim, Jeong-Ho;Bae, Seok-Hwan;Kim, Ki-Jin;Yoo, Se-Jong
    • Journal of the Korea Safety Management & Science
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    • v.17 no.1
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    • pp.125-130
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    • 2015
  • Techniques, using physical wedge filter and using dynamic wedge filter and FIF(Field in Field) and ISCT(Irregular Surface Compensating Technique), have been developed according to progress of radiation therapy of breast cancer. Measurement of dose was done to judge the usefulness of technique using three cases, non tissue loss after breast conserving operating and tissue loss after breast conserving operating and mastectomy. Dose indexes of breast tissue, CI (Conformity Index), HI (Homogeneity Index) and QOC (Quality of Coverage), dose index of skin, or dose indexes of lung, volume of 50 percent dose and 20 percent dose were estimated and compared. Using dynamic wedge filter is useful plan at non tissue loss allowing for high dose of lung. FIF and ISCT are useful plan at tissue loss. ISCT is useful plan at mastectomy. Henceforth, we need to apply to valid plan and body type and thorax size.

Comparative study of dose due to the change of fluoroscopy pulse rate of Epidural Injection treatment time (Epidural Injection시술시 투시율 변화에 따른 선량비교연구)

  • Seo, Jeong-Beom;Oh, Dong-Hoon;Lee, Jeong-Beom;Lee, Jong-Woong
    • Korean Journal of Digital Imaging in Medicine
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    • v.15 no.1
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    • pp.21-26
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    • 2013
  • To be investigated and measures to reduce the medical exposure of patients to change the Epidural Injection time Fluoroscopy Pulse Rate in this study. Was conducted in 50 patients who underwent surgery Epidural Injection performed by interventional care of Konkuk University Hospital from January to April 2013. The treatment time with the change of Pulse rate, is measured in minutes fluoroscopy time, and measured the area dose (${\mu}Gym^2$) and depth dose (mGy). Using the Image J program, to measure the PSNR and SNR. The fluoroscopy time as a result surgery, there was no significance in the statistical analysis, and depth dose is 34.3 to 34.9%, was reduced from 35.8 to 38.7% the area dose. It is possible to reduce the appropriate Pulse rate, to reduce the dose without statistical analysis significance fluoroscopy time.

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Comparison of Estimated and Measured Doses of Dual-energy Computed Tomography (Dual-energy 컴퓨터단층촬영에서 장비 제공선량과 측정선량 비교)

  • Kim, Yung-Kyoon;Kim, Yon-Min
    • Journal of radiological science and technology
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    • v.41 no.5
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    • pp.405-411
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    • 2018
  • We will provide basic data on the evaluation of patient dose in terms of DECT quality control by comparing the equipment-provided dose with the measured dose according to the configuration method of the X-ray generator by the manufacturer of the dual-energy CT unit. For computed tomography (CT) equipment, Discovery 750HD, Aquilion ONE GENESIS Edition, and Somatom Definition Flash were used. The $CTDI_{vol}$ value was measured by inserting the Unfors Xi ion chamber into a 32 cm PMMA acryl Phantom. The results of estimated $CTDI_{vol}$ DECT and measured $CTDI_{vol}$ showed that the dose difference between DECT 80 + 140 kVp of G company was at least 0.51% and -1.90% max, and measured $CTDI_{vol}$ was slightly lower (p<0.05). The difference of 80 + 140 kVp of S company was the minimum of 5.84% and the maximum of 7.52% (p<0.05). The measured $CTDI_{vol}$ was less than estimated $CTDI_{vol}$. The C company's 80 + 135 kVp showed a difference of at least 7.58% and a maximum of 13.58% (P<0.05), and all of measured $CTDI_{vol}$ was less. The linearity of exposure dose for all DECT equipment was very linearly reflected with $R^2$ being 0.97 or above, and the measured dose of the ionization chamber was less than the predicted dose of the monitor.

The effect of photon energy on intensity-modulated radiation therapy (IMRT) plans for prostate cancer

  • Sung, Won-Mo;Park, Jong-Min;Choi, Chang-Heon;Ha, Sung-Whan;Ye, Sung-Joon
    • Radiation Oncology Journal
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    • v.30 no.1
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    • pp.27-35
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    • 2012
  • Purpose: To evaluate the effect of common three photon energies (6-MV, 10-MV, and 15-MV) on intensity-modulated radiation therapy (IMRT) plans to treat prostate cancer patients. Materials and Methods: Twenty patients with prostate cancer treated locally to 81.0 Gy were retrospectively studied. 6-MV, 10-MV, and 15-MV IMRT plans for each patient were generated using suitable planning objectives, dose constraints, and 8-field setting. The plans were analyzed in terms of dose-volume histogram for the target coverage, dose conformity, organs at risk (OAR) sparing, and normal tissue integral dose. Results: Regardless of the energies chosen at the plans, the target coverage, conformity, and homogeneity of the plans were similar. However, there was a significant dose increase in rectal wall and femoral heads for 6-MV compared to those for 10-MV and 15-MV. The $V_{20Gy}$ of rectal wall with 6-MV, 10-MV, and 15-MV were 95.6%, 88.4%, and 89.4% while the mean dose to femoral heads were 31.7, 25.9, and 26.3 Gy, respectively. Integral doses to the normal tissues in higher energy (10-MV and 15-MV) plans were reduced by about 7%. Overall, integral doses in mid and low dose regions in 6-MV plans were increased by up to 13%. Conclusion: In this study, 10-MV prostate IMRT plans showed better OAR sparing and less integral doses than the 6-MV. The biological and clinical significance of this finding remains to be determined afterward, considering neutron dose contribution.

Assessment of Internal Dose by $^3H\;&\;^{14}C$ of Total Diet for Inhabitants near Wolsung Nuclear Power Plants

  • Park, G.;Lin, X.J.;Kim, W.;Kang, H.D.;Doh, S.H.;Kim, D.S.;Kim, C.K.
    • Journal of Radiation Protection and Research
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    • v.28 no.1
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    • pp.51-57
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    • 2003
  • To assess the internal dose by $^3H\;&\;^{14}C$ in total diet of inhabitants near Wolsung Nuclear Power Plants, TFWT, OBT and $^{14}C$ concentration in total diet was analyzed for collection region and time. TFWT, OBT and $^{14}C$ concentrations were in the range of 3.19-42.2 Bq/L, 1.00-39.4 Bq/L, and 0.230-0.855 Bq/gC, respectively. The calculated annual effective dose with TFWT, OBT and $^{14}C$ is $6.10{\times}10^{-5}mSv/y,\;3.71{\times}10^{-5}mSv/y\;and\;7.08{\times}10^{-3}mSv/y$, respectively. And then annual internal dose with total diet for inhabitants near Wolsung NPPs is about $7.18{\times}10^{-3}mSv/y$, which is about 0.72% of annual effective dose limit 1 mSv/y.

Rapid Optimization of Multiple Isocenters Using Computer Search for Linear Accelerator-based Stereotactic Radiosurgery (Multiple isocenter를 이용한 뇌정위적 방사선 수술시 컴퓨터 자동 추적 방법에 의한 고속의 선량 최적화)

  • Suh Tae-suk;Park Charn Il;Ha Sung Whan;Yoon Sei Chul;Kim Moon Chan;Bahk Yong Whee;Shinn Kyung Sub
    • Radiation Oncology Journal
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    • v.12 no.1
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    • pp.109-115
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    • 1994
  • The purpose of this paper is to develop an efficient method for the quick determination of multiple isocenters plans to provide optimal dose distribution in sterotactic radiosurgery. A Spherical dose model was developed through the use of fit to the exact dose data calculated in a 18cm diameter of spherical head phantom. It computes dose quickly for each spherical part and is useful to estimate dose distribution for multiple isocenters. An automatic computer search algorithm was developed using the relationship between the isocenter move and the change of dose shape, and adapted with a spherical dose model to determine isocenter separation and cellimator sizes quickly and automatically. A spheric81 dose model shows a comparable isodose distribution with exact dose data and permits rapid calculations of 3-D isodoses. the computer search can provide reasonable isocenter settings more quickly than trial and error types of plans, while producing steep dose gradient around target boundary. A spherical dose model can be used for the quick determination of the multiple isocenter plans with 3 computer automatic search. Our guideline is useful to determine the initial multiple isocenter plans.

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Radiation Dose and Image Quality of Low-dose Protocol in Chest CT: Comparison of Standard-dose Protocol (흉부 CT촬영에서 저선량 프로토콜의 선량과 화질: 표준선량 프로토콜과 비교)

  • Lee, Won-Jeong;Ahn, Bong-Seon;Park, Young-Sun
    • Journal of Radiation Protection and Research
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    • v.37 no.2
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    • pp.84-89
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    • 2012
  • The purpose of this study was to compare radiation dose and image quality between low-dose (LDP) and standard-dose protocol (SDP). LDP (120 kVp, 30 mAs, 2-mm thickness) and SDP (120 kVp, 180 mAs, 1.2-mm thickness) images obtained from 61 subjects were retrospectively evaluated at level of carina bifurcation, using multi-detector CT (Brilliance 16, Philips Medical Systems). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated at ascending aorta and infraspinatus muscle, from CT number and back-ground noise. Radiation dose from two protocols measured at 5-point using acrylic-phantom, and CT number and noise measured at 4-point using water-phantom. All statistical analysis were performed using SPSS 19.0 program. LDP images showed significantly more noise and a significantly lower SNR and CNR than did SDP images at ascending aorta and infraspinatus muscle. Noise, SNR and CNR were significantly correlated with body mass index (p<0.001). Radiation dose, SNR and CNR from phantom were significant differences between two protocols. LDP showed a significant reduction of radiation dose with a significant change in SNR and CNR compared with SDP. Therefore, exposure dose on LDP in clinical applications needs resetting highly more considering image quality.

Adaptive Response Induced by Low Dose Ionizing Raditation in Human Cervical Carcinoma Cells

  • Kim, Jeong -Hee;Lee, Kyung -Jong;Cho, Chul -Koo;Yoo, Seong -Yul;Kim, Tae -Hwan;Ji, Young -Hoon;Kim, Sung -Ho
    • Archives of Pharmacal Research
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    • v.18 no.6
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    • pp.410-414
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    • 1995
  • Adaptive response induced by low dese .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray irradiation in human cervical carcinoma cells was examined. Cells were exposured to low dose of .gamma.-ray (1-cGy) followed by high doses of r-ray irradiation (0,1,2,3,5,7 and 9Gy for chlnogenic assay or 1.5Gy for micronucleus assay) with various time intervals. Survival fractions of cells in both low dose-irradiated and unirrated groups were analyzed by clonogenic assay. Surviva fractions of low dose-irradiated in cell survival was maximum when low and high dose irradiation time interval was 4 hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enutained from survival fractions analyzed by clonogenic assay, maximum when low and high dose irradiation time interval was 4hr. Frequencies of micronuclei which is an indicative of chromosome aberration were also enumerated in both low dose-irradiated and unirradiated groups. In consiststent with the result obtained from survival fractions analyzed by clonogenic assay, maximum reduction in frquencies of micronuclei was observed when low dose radiation was given 4 hr prior to high response to subsequent high dose .gamma.-ray irradiation in human cervical carcinomal cells. Our data suggest that one of the possible mechanisms of adaptive response induced by low dose rediation is the increase in repair of DNA double strand breaks in low dose radiation-adapted cells.

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Effect of a Dose-Escalation Regimen for Improving Adherence to Roflumilast in Patients with Chronic Obstructive Pulmonary Disease

  • Hwang, Hyunjung;Shin, Ji Young;Park, Kyu Ree;Shin, Jae Ouk;Song, Kyoung-hwan;Park, Joonhyung;Park, Jeong Woong
    • Tuberculosis and Respiratory Diseases
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    • v.78 no.4
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    • pp.321-325
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    • 2015
  • Background: The adverse effects of the phosphodiesterase-4 inhibitor roflumilast, appear to be more frequent in clinical practice than what was observed in chronic obstructive pulmonary disease (COPD) clinical trials. Thus, we designed this study to determine whether adverse effects could be reduced by starting roflumilast at half the dose, and then increasing a few weeks later to $500{\mu}g$ daily. Methods: We retrospectively investigated 85 patients with COPD who had taken either $500{\mu}g$ roflumilast, or a starting dose of $250{\mu}g$ and then increased to $500{\mu}g$. We analyzed all adverse events and assessed differences between patients who continued taking the drug after dose escalation and those who had stopped. Results: Adverse events were reported by 22 of the 85 patients (25.9%). The most common adverse event was diarrhea (10.6%). Of the 52 patients who had increased from a starting dose of $250{\mu}g$ roflumilast to $500{\mu}g$, 43 (82.7%) successfully maintained the $500{\mu}g$ roflumilast dose. No difference in factors likely to affect the risk of adverse effects, was detected between the dose-escalated and the discontinued groups. Of the 26 patients who started with the $500{\mu}g$ roflumilast regimen, seven (26.9%) discontinued because of adverse effects. There was no statistically significant difference in discontinuation rate between the dose-escalated and the control groups (p=0.22). Conclusion: Escalating the roflumilast dose may reduce treatment-related adverse effects and improve tolerance to the full dose. This study suggests that the dose-escalated regimen reduced the rate of discontinuation. However, longer-term and larger-scale studies are needed to support the full benefit of a dose escalation strategy.

Single-Dose Toxicity and Four Week Repeated-Dose Toxicity Study on Tensolin-F® (3,9-diferuloyl-6-oxopterocarpen) (Tensolin-F® (3,9-diferuloyl-6-oxopterocarpen)의 단회 독성시험 및 4주 반복투여 독성시험)

  • Kim, Keun-Su;Park, Sung-Min;Lee, Nam-Jin;Pyo, Hyeong-Bae;Chai, Hee-Yul;Jung, Yu-Ri;Lin, Chun-Mai;Kim, Sun-Hee;Lee, Hye-Young;Kang, Jong-Koo
    • Toxicological Research
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    • v.23 no.4
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    • pp.405-413
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    • 2007
  • This study was to investigate single and repeated-dose toxicities of Tensolin-$F^{(R)}$, an anti-wrinkle agent, in Sprague-Dawley (SD) rats or ICR mice. In single-dose oral toxicity study, the test materials were administered once by gavage to male and female SD rats at dose levels of 0 and 2,000 mg/kg. No dead animals and abnormal necropsy findings were found in control and Tensolin-$F^{(R)}$ treated group. Therefore, the approximate lethal dose of Tensolin-$F^{(R)}$ was considered to be higher than 2,000 mg/kg in rats. In the 4-week repeated oral toxicity study, the test material was administered once daily by gavage to male and female ICR mice at dose levels of 0, 25, 50 and 100 mg/kg/day for 4-weeks. In the results, no abnormality was observed in mortality, clinical findings, body weight changes, food and water consumptions, opthalmoscopic findings, necropsy findings, histopathological findings. In hematological analysis, there was a trend of increase in reticulocyte at male 25 mg/kg, although such changes were in normal ranges. On the other hand, there was a trend of decrease in hemoglobin at female 50, 100 mg/kg, such changes were in normal ranges. In addition, serum biochemical parameters including sodium, BUN and chloride increased at 25, 50 and 100 mg/kg. Relative organ weights of right testis, brain, lung and left epididymis were increased in 100 mg/kg groups of male rats in contrast to not change in female groups. However, these changes of relative organ weights, hematological and serum biochemical parameters were not accompanied with related signs such as histopathological changes or clinical findings. In conclusion, 4-week repeated oral dose of Tensolin-$F^{(R)}$ to ICR mice did not cause apparent toxicological change at the dose of 25, 50, 100 mg/kg body weight. Consequently the no-observed-adverse-effect level (NOAEL) for Tensolin-$F^{(R)}$ in ICR mice following gavage for at least 4-week is higher than 100 mg/kg/day.