• Korean Journal of Radiology
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• v.21 no.6
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• pp.736-745
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• 2020

Objective: To identify the initial chest computed tomography (CT) findings and clinical characteristics associated with the course of coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: Baseline CT scans and clinical and laboratory data of 72 patients admitted with COVID-19 pneumonia (39 men, 46.2 ± 15.9 years) were retrospectively analyzed. Baseline CT findings including lobar distribution, presence of ground glass opacities, consolidation, linear opacities, and lung severity score were evaluated. The outcome event was recovery with hospital discharge. The time from symptom onset to discharge or the end of follow-up (for those remained hospitalized) was recorded. Data were censored in events such as death or discharge without recovery. Multivariable Cox proportional hazard regression was used to explore the association between initial CT, clinical or laboratory findings, and discharge with recovery, whereby hazard ratio (HR) values < 1 indicated a lower rate of discharge at four weeks and longer time until discharge. Results: Thirty-two patients recovered and were discharged during the study period with a median length of admission of 16 days (range, 9 to 25 days), while the rest remained hospitalized at the end of this study (median, 17.5 days; range, 4 to 27 days). None died during the study period. After controlling for age, onset time, lesion characteristics, number of lung lobes affected, and bilateral involvement, the lung severity score on baseline CT (> 4 vs. ≤ 4 [reference]: adjusted HR = 0.41 [95% confidence interval, CI = 0.18-0.92], p = 0.031) and initial lymphocyte count (reduced vs. normal or elevated [reference]: adjusted HR = 0.14 [95% CI = 0.03-0.60], p = 0.008) were two significant independent factors that influenced recovery and discharge. Conclusion: Lung severity score > 4 and reduced lymphocyte count at initial evaluation were independently associated with a significantly lower rate of recovery and discharge and extended hospitalization in patients admitted for COVID-19 pneumonia.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1350-1360
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• 2023

Purpose To evaluate the factors that predict symptomatic dislodgement of a percutaneous transhepatic biliary drainage (PTBD) catheter in patients with malignant biliary obstruction. Materials and Methods This retrospective study included 572 patients with malignant biliary obstruction who underwent 733 PTBD catheter insertions between January 2010 and February 2015. The duration of catheter placement, approach site, location of the catheter tip, insertion angle, presence of a closed-loop pigtail, and tube diameter were evaluated. Results During the follow-up period, 224 PTBD catheter dislodgements (30.56%) were observed in 157 patients. Among them, 146 (19.92%) were symptomatic. The mean duration from catheter insertion until dislodgement was 32 days (range: 1-233 days). Male (odds ratio [OR]: 1.636, 95% confidence interval [CI]: 1.131-2.367, p = 0.009), right-sided approach (OR: 1.567, 95% CI: 1.080-2.274, p = 0.018), increased insertion angle (OR: 1.015, 95% CI: 1.005-1.026, p = 0.005), and incomplete closed-loop pigtail formation (OR: 1.672, 95% CI: 1.098-2.545, p = 0.016) were independent factors predictive of symptomatic dislodgement of a PTBD catheter. Conclusion Factors predictive of symptomatic catheter dislodgement included male sex, a right-sided approach, increased insertion angle, and incomplete closed-loop pigtail formation.

• Progress in Medical Physics
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• v.25 no.3
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• pp.167-175
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• 2014

The purpose of this study is to evaluate the variation of the dose which is delivered to the patients with glottis cancer under IMRT (intensity modulated radiation therapy) by using the 3D registration with CBCT (cone beam CT) images and the DIR (deformable image registration) techniques. The CBCT images which were obtained at a one-week interval were reconstructed by using B-spline algorithm in DIR system, and doses were recalculated based on the newly obtained CBCT images. The dose distributions to the tumor and the critical organs were compared with reference. For the change of volume depending on weight at 3 to 5 weeks, there was increased of 1.38~2.04 kg on average. For the body surface depending on weight, there was decreased of 2.1 mm. The dose with transmitted to the carotid since three weeks was increased compared be more than 8.76% planned, and the thyroid gland was decreased to 26.4%. For the physical evaluation factors of the tumor, PITV, TCI, rDHI, mDHI, and CN were decreased to 4.32%, 5.78%, 44.54%, 12.32%, and 7.11%, respectively. Moreover, $D_{max}$, $D_{mean}$, $V_{67.50}$, and $D_{95}$ for PTV were increased or decreased to 2.99%, 1.52%, 5.78%, and 11.94%, respectively. Although there was no change of volume depending on weight, the change of body types occurred, and IMRT with the narrow composure margin sensitively responded to such a changing. For the glottis IMRT, the patient's weight changes should be observed and recorded to evaluate the actual dose distribution by using the DIR techniques, and more the adaptive treatment planning during the treatment course is needed to deliver the accurate dose to the patients.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3785-3791
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• 2016

Background: Previous studies have assessed the association between the Cytotoxic T-lymphocyte Antigen-4(CTLA-4) polymorphism with the risk of malignant bone tumor, but the conclusions were inconsistent. We aimed to clarify association of cytotoxic T-lymphocyte antigen-4 polymorphisms with malignant bone tumors risk by performing a meta-analysis. Materials and Methods: The databases including PubMed, EMBase databases and the Cochrane Library were searched to identify the eligible studies prior to January 30 2016. Odds ratio (OR) with 95% confidence interval (95%CI) were used to estimate the strengths of the association between the CTLA-4 polymorphism and the malignant bone tumor risks. The meta-analysis was performed by STATA 12.0. Results: Four individual studies with a total of 1003 cases with malignant bone tumor and 1162 controls were included in our meta-analysis. The results of meta-analysis on those data demonstrated that CTLA-4 +49G>A polymorphism was associated with the risk of Ewing's sarcoma and osteosarcoma strongly (A vs. G: OR=1.36, 95%CI:1.20-1.54, p=0.000; AA+AG vs. GG: OR=1.35, 95%CI:1.14-1.61, p=0.001; AA vs. GG: OR=2.24, 95%CI:1.67-2.99, p=0.000; AA vs. AG+GG: OR=2.00, 95%CI:1.53-2.62, p=0.000), but CTLA-4 -318C/T polymorphism was not associated with the risk of malignant bone tumor (C vs. T: OR=0.76, 95%CI:0.76-1.08, p= 0.262; CC+CT vs. TT: OR=0.70, 95%CI:0.41-1.20, p= 0.198; CC vs. TT: OR=0.69, 95%CI:0.40-1.19, p= 0.183; CC vs. CT+TT: OR=0.92, 95%CI:0.75-1.13, p= 0.419). Subgroup analysis showed that there are significantly positive correlations between CTLA-4 +49G>A polymorphism and increased risks of malignant bone tumors in large size of sample (A vs. G: OR=1.347, 95%CI: 1.172,1.548, p=0.000; AA vs. GG: OR=2.228, 95%CI: 1.608,3.085, p=0.000), Ewing's Sarcoma or Osteosarcoma (A vs. G: OR=1.361, 95%CI: 1.201,1.540, p=0.000; AA vs. GG: OR=2.236, 95%CI: 1.674,2.986, p=0.000), and PCR-RFLP or Sequencing(A vs. G: OR=1.361, 95%CI: 1.201,1.540, p=0.000; AA vs. GG: OR=2.236, 95%CI: 1.674,2.986, p=0.000), but CTLA-4 -318C/T polymorphism was not associated with the risk of malignant bone tumors in diagnosis, genotype method, and sample size (all p>0.05). Conclusions: CTLA-4 +49A/G variant was associated with an increased risk of developing the malignant bone tumors, such as Ewing's sarcoma and osteosarcoma. However, it failed to show the association between CTLA-4 -318C/T polymorphism and the risk of malignant bone tumors. Future large-scale studies remain to be done to confirm our conclusions.

• Tuberculosis and Respiratory Diseases
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• v.66 no.4
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• pp.280-287
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• 2009

Background: The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), became an attractive therapeutic option for advanced non-small-cell lung cancer (NSCLC). Several studies suggested that there might be some different efficacy or response predictors between gefitinib and erlotinib. We compared the efficacy and toxicity of gefitinib and erlotinib in Korean patients with advanced NSCLC and evaluated specific predictors of response for both gefitinib and erlotinib. Methods: We collected the clinical information on patients with advanced NSCLC, who were treated with gefitinib or erlotinib at the Ewha Womans University Hospital, between July 2003 and February 2009. Median survival times were calculated using the Kaplan-Meier method. Results: Eighty-six patients (52 gefitinib vs. 34 erlotinib) were enrolled. Patient median age was 64 years; 53 (62%) subjects were male. Out of the 86 patients treated, 83 received response evaluation. Of the 83 patients, 35 achieved a response and 12 experienced stable disease while 36 experienced progressive disease, resulting in a response rate of 42% and a disease control rate of 57%. After a median follow-up of 502 days, the median progression-free and overall survival time was 129 and 259 days, respectively. Comparing patients by treatment (gefitinib vs erlotinib), there were no significant differences in the overall response rate (44% vs. 39%, p=0.678), median survival time (301 days vs. 202 days, p=0.151), or time to progression (136 days vs. 92 days, p=0.672). Both EGFR-TKIs showed similar toxicity. In a multivariate analysis using Cox regression model, adenocarcinoma was an independent predictor of survival (p=0.006; hazard ratio [HR], 0.487; 95% confidence interval [CI], 0.292-0.811). Analyses of subgroups did not show any difference in response predictors between gefitinib and erlotinib. Conclusion: Comparing gefitinib to erlotinib, there were no differences in the response rate, overall survival, progression-free survival, or toxicity. No specific predictor of response to each EGFR-TKI was identified.

• Radiation Oncology Journal
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• v.14 no.4
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• pp.299-306
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• 1996

Purpose : Respiratory symptoms related with malignant airway disease have been the main causes of lowered qualify of life and also sometimes may be life-threatening if not properly managed. The authors report the short-term experiences of endobronchial brachytherapy for symptomatic malignant airway obstruction using high dose rate after-loading brachytherapy unit. Materials and Methdos : Twenty-five Patients with symptomatic malignant airway obstruction were treated with endobronchial brachytherapy between the period of December 1994 and March 1996 at Department of Radiation Oncology of Samsung Medical Center Twenty-one ($84\%$) were patients with non-small cell lung cancer, three with tracheal malignancies, and one with recurrence of esophageal cancer. Twenty Patients were given elective external beam radiation therapy, while six were given endobronchial laser evaporation therapy on emergency bases in addition to endobronchial brachytherapy. Three procedures for each patient were planned and total of 70 procedures were completed. Results : Improvement rates of major respiratory symptoms after endobronchial brachytherapy procedures were $88\%$(22/25). $96\%$(22/23), $100\%$ (15/15), and $100\%$(9/9) for cough, dyspnea, hemoptysis and obstructive pneumonia, respectively. ECOG performance scores were improved in $56\%$ of total patients group, while there was no case with worsened ECOG score. Fifteen patients died and the median interval from the start of treatment to death was 4 months (range: $1\~17$ months), while that of ten survivors was 9 months (range $5\~19$ months). There were five patients with controlled intrathoracic disease, who have survived over one rear. All deaths were associated with uncontrolled local and/or distant disease. Four Patients died of massive fatal hemoptysis, three of who received emergency endobronchial laser evaporation therapy before the start of endobronchial brachytherapy. Conclusion : Endobronchial brachytherapy has been confirmed as an excellent palliative treatment modality improving respiratory symptoms as well as patients' general performance status. Based on the current observations, use of endobronchial brachytherapy in curative setting as a boost technique may be warranted.

• The Korean Journal of Nuclear Medicine
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• v.28 no.3
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• pp.384-390
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• 1994

Authors retrospectively compared the 99mTc MDP bone scans and corresponding MR imagings in 20 patients with histologically proven malignancy, Mean interval of the two studies was 16.6 days, Cancer diagnosis Included 8 lung, 2 each of colon, breast, stomach, 1 each of prostate, thyroid, malignant lymphoma and 3 adenocarcinoma of unknown primary site. Of the 105 regions compared, :t6 regions were positive for metastases in bone scans or MR imagings. 30 regions(65.2%) were positive by bone scan and 44 regions(95.7%) by MR imaging. 87 regions(82.9%) were concordantly positive or negative by bone scan and MR imaging, but 18 regions(17.1%) were discordant. In the discordant regions, 16 regions positive in MR imaging were negative in bone scan. The greatest number of discordant findings occured in the cervical region and in the patient with stomach cancer. Our results suggest that the sensitivity of MR Imaging is greater than that of bone scan in detecting spinal metastases. And bone scan is useful screening test of metastasis for evaluating entire skeleton including spine.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.343-349
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• 1995

Background : For biological dosimetry of radiation exposure, both observing hematologic change and calculating Ydr by chromosomal analysis as biological indicators are widely used. However, due to the lack of studies on biological dosimetry of radiation dose absorbed in the body such as in the cases of radioactive iodine therapy, the maximal and safe dose is not well known, nor is the extent to which the body can safely endure radiation exposure. Purpose : To investegate the practical applicability of hematologic changes and Ydr as an indicator for estimating radiation exposure, to patients with thyroid diseases after doses of radioactive iodine. Material and Methods : 5 patients with hyperthyroidism and 35 patients who have had thyroid cancer operation were under treatment with radioactive iodine, changes in number of lymphocytes were tracked and Ydr was calculated for more than 2 months by chromosomal analysis in peripheral lymphocytes. Results ; 1) The number of lymphocytes began to decrease 2 weeks after doses of radioactive iodine, and reached the nadir after 6 and 8 weeks, then gradually recovered. 2) The nadir count of lymphocytes was reversely correlated with the administered dosage of radioactive iodine. 3) Ydr was generally stable between 2 and 8 weeks. 4) The maximal value of Ydr was correlated with the administered dosage of radioactive iodine. 5) Ydr value at the 2nd week increased with augmented dosage of radioactive iodine. 6) Ydr value at the 2nd week was correlated with fall of lymphocyte count. Conclusion : Patients must be closely observed, because temporary bone marrow suppression and slight chromosomal aberration can be produced by even generally used dosages of radioactive iodine for diagnosis and therapy. Maximal percent fall of lymphocyte count, Ydr at the 2 week interval and maximal Ydr can be used as the biological predictor of administered dosage of radioactive iodine.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.303-310
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• 1998

Purpose : To evaluate the results of the treatment of locally advanced but resectable rectal cancers and to analyze prognostic factors. especially with the emphasis on the treatment time factor. Materials and Methods : There were 71 patients with rectal cancer who had been treated by curative surgical procedure and postoperative radiotherapy from August 1989 to December 1993. The minimum follow up period was 24 months and the median follow-up was 35 months Radiation therapy had been given by 6 MV linear accelerator by parallel opposing or four-box portals. Whole pelvis was treated up to 5040 cGy in most cases. Systemic chemotherapy had been given in 94$\%$ of the patients, mostly with 5-FU/ACNU regimen. Assessment for the overall and disease-free survival rates were done by life-table method and prognostic factors by Log-Rank tests. Results : Five-year overall survival, disease-free survival were 58.8$\%$ and 57$\%$, respectively. Two-year local control rate was 76.6$\%$. Stage according to Modified Astler-Coller (MAC) system, over 4 positive lymph nodes, over 6weeks interval between definitive surgery and adjuvant radiotherapy and over 7 days of interruption during radiotherapy period were statistically significant, or borderline significant prognostic factors. Conclusion : The treatment results of patients with rectal cancers are comparable to those of other large institutes. The treatment results for the patients with bowel wall penetration and/or positive regional lymph nodes were still discouraging for their high local recurrence rate for the patients with MAC 'c' stage diseases and high distant metastases rate even for the patients with node-negative diseases. Maybe more effective regimen of chemotherapy would be needed with proper route and schedule. To maximize postoperative adjuvant treatment. radiotherapy should be started at least within 6 weeks after surgery and preferably as soon as wound healing is completed. Interruption of treatment during radiotherapy course affects disease-free survival badly, especially if exceeds 7 days. So, the total treatment period trout definitive surgery to the completion of radiotherapy should be kept as minimal as possiable.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.27-35
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• 2017

Purpose: On the left side, breast cancer patients have more side effects than those on the right side because of unnecessary doses in normal organs such as heart and lung. DIBH is performed to reduce this. To evaluate the dose of peripheral organs in the left breast cancer including supraclavicular lymph nodes and internal mammary lymph nodes according to the treatment planning method of Conventional Radiation Therapy, Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy. Materials and Methods: We performed CT-simulation using free breathing and deep inspiration breath-hold technique for 8 patients including left supraclavicular lymph nodes and internal mammary lymph nodes. Based on the acquired CT images, the contour of the body is drawn and the convention is performed so that $95%{\leftarrow}PTV$, $Dmax{\leftarrow}110%$. Conventional Radiation Therapy used a one portal technique on the supraclavicular lymph node and used a field in field technique tangential beam on the breast. Intensity Modulated Radiation Therapy was composed of 7 static fields. Volumetric Modulated Arc Therapy was planned using 2 ARC with a turning radius of $290^{\circ}$ to $179^{\circ}$. The peripheral normal organs dose was analyzed by referring to the dose volume of Eclipse. Results: By applying the deep inspiration breath-hold technique, the mean interval between the heart and chest wall increased $1.6{\pm}0.6cm$. The mean dose of lung was $19.2{\pm}1.0Gy$, which was the smallest value in Intensity Modulated Radiation Therapy. The V30 (%) of the heart was $2.0{\pm}1.9$, which was the smallest value in Intensity Modulated Radiation Therapy. In the left anterior descending coronary artery, the dose was $25.4{\pm}5.4Gy$, which was the smallest in Intensity Modulated Radiation Therapy. The maximum dose value of the Right breast was $29.7{\pm}4.3Gy$ at Intensity Modulated Radiation Therapy. Conclusion: When comparing the values of surrounding normal organs, Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy were applicable values for treatment. Among them, Intensity Modulated Radiation Therapy is considered to be a suitable treatment planning method.