• Journal of radiological science and technology
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• v.42 no.4
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• pp.279-284
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• 2019

The purpose of this study was to find the best protocol for balance of image quality and dose in brain CT scan. Images were acquired using dual-source CT and AAPM water phantom, noise and dose were measured, and effective dose was calculated using computer simulation program ALARA(S/W). In order to determine the ratio of image quality and dose by each protocol, FOM (figure of merits) equation with normalized DLP was presented and the result was calculated. judged that the ratio of image quality and dose was excellent when the FOM maximized. Experimental results showed that protocol No. 21(120 kVp, 10 mm, 1.5 pitch) was the best, the organ with the highest effective dose was the brain(33.61 mGy). Among organs with high radiosensitivity, the thyroid gland was 0.78 mGy and breast 0.05 mGy. In conclusion, the optimal parameters and the organ dose in the protocol were also presented from the experiment, It may be helpful to clinicians who want to know the protocol about the optimum state of image quality and dose.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.1
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• pp.13-22
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• 2015

Purpose : We investigated the safety of Intrabeam$^{TM}$ system, X-ray unit for Intraoperative Radiotheray (IORT) by measuring surface dose using Optically Stimulated Luminescent Dosimeter(OSLD). Materials and Methods : 30 patients were selected, who were in breast cancer patients and had an operation of breast conserving surgery (BCS). At the inner surface of tumor bed, 20 Gy were described, and 5 Gy at 1cm depth from the inner surface. Along the size of tumor bed which could be decided after resection of tumor, the size of applicator were determined. Usual treatment time were from 18 to 40 minutes. For the measurement of surface doses, OSLD were placed at superior(U1,2), inferior(D1,2), lateral(L1,2) and medial(M1,2) directions from the center of applicator. Each direction, two OSLD were placed at 0.5 cm and 1.5 cm from the center. Mean, maximum, and minimum doses were analyzed to be compared. Results : Mean values were U1 $2.23{\pm}0.80Gy$, U2 $1.54{\pm}0.53Gy$, D1 $1.73{\pm}0.63Gy$, D2 $1.25{\pm}0.45Gy$, L1 $1.95{\pm}0.82Gy$, L2 $1.38{\pm}0.42Gy$, M1 $2.03{\pm}0.70Gy$, and M2 $1.51{\pm}0.58Gy$. Maximum values were 4.34 Gy at U1, and Minimum values were 0.45 Gy at M2. 13.3 % of patient (4pts out of 30) were reported that surface dose were over 4 Gy. Conclusion : The fact that skin dose of all patients were less than 5 Gy based on OSLD measurement showed the safety of Intrabeam$^{TM}$ system. In the relatively small breast volume, the tendency that surface dose was increased had been shown, which was analyzed by the data of patients who irradiated over 4Gy at skin surface. Therefore, for appropriate indication for IORT, it is suggested that breast volume as well as the size and position of tumor should be carfully considered.

• Radiation Oncology Journal
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• v.25 no.2
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• pp.109-117
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• 2007

[ $\underline{Purpose}$ ]: To evaluate the incidences and potential predictive factors for symptomatic radiation pneumonitis (SRP) and radiographic pulmonary toxicity (RPT) following adjuvant radiotherapy (RT) for patients with breast cancer. A particular focus was made to correlate RPT with the dose volume histogram (DVH) parameters based on three-dimensional RT planning (3D-RTP) data. $\underline{Materials\;and\;Methods}$: From September 2003 through February 2006, 171 patients with breast cancer were treated with adjuvant RT following breast surgery. A radiation dose of 50.4 Gy was delivered with tangential photon fields on the whole breast or chest wall. A single anterior oblique photon field for supraclavicular (SCL) nodes was added if indicated. Serial follow-up chest radiographs were reviewed by a chest radiologist. Radiation Therapy Oncology Group (RTOG) toxicity criteria were used for grading SRP and a modified World Health Organization (WHO) grading system was used to evaluate RPT. The overall percentage of the ipsilateral lung volume that received ${\geq}15\;Gy\;(V_{15}),\;20\;Gy\;(V_{20})$, and $30\;Gy\;(V_{30})$ and the mean lung dose (MLD) were calculated. We divided the ipsilateral lung into two territories, and defined separate DVH parameters, i.e., $V_{15\;TNGT},\;V_{20\;TNGT},\;V_{30\;TNGT},\;MLD_{TNGT}$, and $V_{15\;SCL},\;V_{20\;SCL},\;V_{30SCL},\;MLD_{SCL}$ to assess the relationship between these parameters and RPT. $\underline{Results}$: Four patients (2.1%) developed SRP (three with grade 3 and one with grade 2, respectively). There was no significant association of SRP with clinical parameters such as, age, pre-existing lung disease, smoking, chemotherapy, hormonal therapy and regional RT. When 137 patients treated with 3D-RTP were evaluated, 13.9% developed RPT in the tangent (TNGT) territory and 49.2% of 59 patients with regional RT developed RPT in the SCL territory. Regional RT (p<0.001) and age (p=0.039) was significantly correlated with RPT. All DVH parameters except for $V_{15\;TNGT}$ showed a significant correlation with RPT (p<0.05). $MLD_{TNGT}$ was a better predictor for RPT for the TNGT territory than $V_{15\;SCL}$ for the SCL territory. $\underline{Conclusion}$: The incidence of SRP was acceptable with the RT technique that was used. Age and regional RT were significant factors to predict RPT. The DVH parameter was good predictor for RPT for the SCL territory while $MLD_{TNGT}$ was a better predictor for RPT for the TNGT territory.

• Progress in Medical Physics
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• v.25 no.4
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• pp.199-204
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• 2014

The purpose of this study is to evaluate the dosimetric outcome of the field-in-field (FIF) plans compared with tangential wedged beams (TWB) plans for whole breast irradiation of breast cancer patients. Twenty patients with right-sided breast cancer and 10 patients with left-sided breast cancer were retrospectively enrolled in this study. We generated a FIF plan and a TWB plan for each patient to compare dosimetric outcomes. The dose the homogeneity index (HI), the conformity index (CI) and the uniformity index (UI) were defined and used for comparison of the dosimetric outcome of the planning target volume (PTV). To compare the dosimetric outcome of the organs at risk, the mean dose ($D_{mean}$) and the percentage of volumes receiving more than 10, 20 and 30 Gy of the ipsilateral lung and heart were used. The FIF plans had significantly lower HI (p=0.002), higher UI (p=0.000) and CI (p=0.000) than those of the TWB plans, which means that the FIF plans were better than the TWB plans in the dosimetric comparisons of the PTV. The $V10_{lung}$ ($17.1{\pm}7.1$ vs. $18.6{\pm}6.6%$, p=0.020) and $V30_{lung}$ ($10.3{\pm}5.1%$ vs. $10.7{\pm}5.2%$, p=0.000) were lower with the FIF plans compared with those of the TWB plans, with statistical significance. For the left-sided breast cancer patients, $D_{mean}$ of the heart ($2.6{\pm}1.3$ vs. $3.2{\pm}1.4$ Gy, p=0.000), $V20_{heart}$ ($3.4{\pm}2.6$ vs. $3.6{\pm}2.8%$, p=0.005) and $V30_{heart}$ ($2.6{\pm}2.3%$ vs. $2.9{\pm}2.4%$, p=0.004) were significantly lower for the FIF plans in comparison with those of the TWB plans. The FIF plans increased the dose homogeneity, conformity and uniformity of the target volume for the whole-breast irradiation compared with the TWB plans. Moreover, FIF plans reduced the doses to the ipsilateral lung and heart.

• 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%).

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.147-151
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• 2016

Automatic exposure control (AEC) is frequently used in many hospitals for Standing Whole Spine examination which is able to control radiation dose with respect to the body type such as body mass index (BMI) and we can measure dose area product (DAP) based on respective patient information. However, few studies have been conducted organ absorbed dose evaluation based on location of patient organ. The purpose of this study was to evaluate the relationships between BMI and organ absorbed dose along with location of patient organ. For that purpose, we calculated absorbed dose with selected 5 patient organ (thyroid, breast, heart, kidney, and pancreas) using a PCXMC simulation tool with measured DAP. According to the results, measured DAP increases with BMI and organ absorbed dose decreases with BMI in anterior organs such as thyroid, breast, and heart. On the other hand, there is no correlation between organ absorbed dose and BMI in posterior organs such as kidney and pancreas. In conclusion, our results demonstrated that the radiation effects are different with respect to BMI and location of patient organ in Standing Whole Spine examination.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4059-4062
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• 2016

Frequencies of polymorphisms of genes BRCA1 and ТР53 in breast cancer (BC) patients with a BC family history and radiation history were assessed and compared in the Semey region of Kazakhstan. The study included 60 women directly irradiated by the activities of the Semipalatinsk test site with a calculated effective equivalent dose of 500 mSv and their first generation descendants (group BC+Her+Exp); 65 women with family BC and absence of radiological history - the effective equivalent dose due to anthropogenic sources not exceeding 50 mSv (group BC+Her-Exp). The comparison group consisted of 65 women patients with breast cancer without family and radiological history (BC-Her-Exp). The control group comprised 60 women without breast cancer and without family and radiological history (nonBC). We carried out the genotyping of the polymorphisms c.2311T>C, c.4308T>C and 5382insC of the BRCA1 gene and rs1042522 of the ТР53 gene. The frequency of the polymorphism c.2311T>C was significantly higher in patients of the group BC+Her+Exp than in healthy women, and of the polymorphism 5382insC in BC+Her+Exp compared to all other groups. The frequency of the rs1042522 polymorphism of ТР53 was significantly higher in all groups of patients with breast cancer compared with the control group. Differences between groups of women with breast cancer were significant only in BC+Her+Exp vs. BC+Her-Exp. Combinations of polymorphisms of the genes BRCA1 and TP53 predominated in women with a family and radiological history.

• Biomolecules & Therapeutics
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• v.20 no.3
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• pp.313-319
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• 2012

In recent years, inhibition of HDACs has emerged as a potential strategy to reverse aberrant epigenetic changes associated with cancer, and several classes of HDAC inhibitors have been found to have potent and specific anticancer activities in preclinical studies. But their precise mechanism of action has not been elucidated. In this study, a novel synthetic inhibitor of HDAC, 3-(4-dimethylamino phenyl)-N-hydroxy-2-propenamide [IN-2001] was examined for its antitumor activity and the underlying molecular mechanisms of any such activity on human breast cancer cell lines. IN-2001 effectively inhibited cellular HDAC activity ($IC_{50}$ = 0.585 nM) inMDA-MB-231 human breast cancer cells. IN-2001 caused a significant dose-dependent inhibition of cell proliferation in estrogen receptor (ER) negative MDA-MB-231human breast cancer cells. Cell cycle analysis revealed that the growth inhibitory effects of IN-2001 might be attributed to cell cycle arrest at $G_0/G_1$ and/or $G_2$/Mphase and subsequent apoptosis in human breast cancer cells. These events are accompanied by modulating several cell cycle and apoptosis regulatory genes such as CDK inhibitors $p21^{WAF1}$ and $p27^{KIP1}$ cyclin D1, and other tumor suppressor genes such as cyclin D2. Collectively, IN-2001 inhibited cell proliferation and induced apoptosis in human breast cancer cells and these findings may provide new therapeutic approaches, combination of antiestrogen together with a HDAC inhibitor, in the hormonal therapy-resistant ER-negative breast cancers. In summary, our data suggest that this histone deacetylase inhibitor, IN-2001, is a novel promising therapeutic agent with potent antitumor effects against human breast cancers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.8-16
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• 2013

We investigated the effect of red cabbage extract (RCE) on cell death in MDA-MB-231 human breast cancer cells. Cells were cultured in the presence 1.0, 1.5, and 2.0 mg/mL concentrations of RCE for 24 hours. MTT assays demonstrated that mitochondrial dehydrogenase activities decreased in a dose-dependent manner in cells (p<0.05). In contrast, the proportion of dual staining with Hoechst 33342/ethidium bromide (EtBr) for cell death increased in a dose-dependent manner in cells (p<0.05). Flow cytometry assays revealed that cell death caused by an apoptotic program increased in a dose-dependent (p<0.05). Also, increased ROS accumulation in cells, as revealed by DCF-DA staining, was observed in a dose-dependent fashion (p<0.05). The apoptosis suppressor gene Bcl-2 decreased significantly at the mRNA level. Pro-apoptotic genes Bax and caspase-3, genes that are related to the last stage of apoptosis significantly increased. The Bcl-2/Bax ratio which is an important indicator of apoptosis, was found to have significantly decreased dose dependence. These results taken together indicate that the effect of red cabbage extract induces cell death in MDA-MB-231 human breast cancer cells.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.93-101
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• 2017

Purpose: In breast cancer radiotherapy, brass mesh bolus has been recently studied to overcome disadvantage of conventional bolus. The purpose of this study is to investigate the stability of first introduced the brass mesh in the country, and evaluate the skin surface dose of that. Materials and Methods: The measurement of skin surface dose was evaluated to verify similar thickness of the Brass mesh bolus that compared conformal tissue equivalent bolus with 5 mm thickness. We used 6 MV photons on an ELEKTA VERSA linear accelerator and optically stimulated luminescent dosimeter (OSLD). In addition, two opposed beam using IMRT phantom was applied to comparative study of brass mesh bolus between tissue equivalent bolus. Results: The results showed that similar thickness of the Brass mesh bolus was 3 mm compared with 5 mm tissue equivalent bolus by measuring the skin surface dose of solid phantom. The surface dose for IMRT thorax phantom using 3 mm brass mesh bolus was about 1.069 times greater than that using tissue equivalent bolus. Conclusion: In this study, we found that the brass mesh bolus improved better reduction of skin sparing effect and dose uniformity than tissue equivalent bolus. However evaluation for various clinic cases should be investigated.