• Journal of the Korean Society of Radiology
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• v.17 no.2
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• pp.243-248
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• 2023

This study aims to analyze the secondary carcinogenesis rate caused by exposure of organs at risk of damage using a glass dosimeter during radiosurgery in vestibular schwannoma disease. Using a pediatric phantom of human tissue equivalent material, the volume of the tumor was set to a total of three volumes: 0.506 cm³, 1.008 cm³, and 2.032 cm³, and a radiosurgery plan was established with an average dose of 18.4 ± 3.4 Gy. After mounting the human body phantom on the table of surgical equipment, glass dosimeters were placed on the right eye, left eye, thyroid gland, thymus, right lung, and left lung to measure the exposure dose, respectively. In this study, the incidence of secondary cancer due to exposure to damaged organs during gamma knife radiosurgery in vestibular schwannoma disease with the largest tumor volume of 2.032 cm³ was measured with a glass dosimeter. This study studies the risk of secondary radiation exposure dose that can occur during stereotactic radiosurgery, and it is considered that it will be used as basic data in the field of radiation damage related to the stochastic effect of radiation in the future.

• Journal of the Korean Society of Radiology
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• v.18 no.1
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• pp.27-36
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• 2024

In this study, When acquisition thyroid scintigraphy images, a parallel hole collimator was applied, and the difference from the pinhole collimator was quantitatively analyzed under each image acquisition condition. Visual size, resolution, sensitivity, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were evaluated using thyroid phantom and point source. When comparing visual size, it was confirmed that an image similar to the size of the pinhole collimator could be obtained only when a magnification ratio of about 2.00 to 2.09 times when applying a parallel hole collimator. There was no tendency in FWHM(mm) measurement using a point source, and sensitivity was high in the parallel hole collimator. SNR and CNR were high when using a low magnification ratio, matrix size of 128×128, and a parallel hole collimator. In images of similar size to the naked eye, when the matrix size was the same, both SNR and CNR were high in the pinhole collimator. Therefore, when performing a thyroid scintigraphy test, if appropriate conditions are set according to the situation of each hospital and a parallel hole collimator is applied, it can be a good option in terms of equipment utilization and work efficiency.

• Clinical and Experimental Pediatrics
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• v.46 no.5
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• pp.459-466
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• 2003

Purpose : AOM is the most common bacterial URI in children. The bacteriology and antibiotic Tx of AOM in children has been studied in many countries. But, there is few study of causative pathogens and antibiotic Tx of AOM in our country. In this aspect, we performed prospective clinical study to confirm the causative pathogens and assess the clinical responses of cefprozil in AOM patients. Methods : Thirty three AOM patients enrolled in this study. Tympanocentesis for isolation of causative pathogens were performed before Tx of cefprozil. The study patients received cefprozil with dose of 15 mg/kg/bid.po/day for 10-12 days, and initially assessed the clinical response at 4-5 days after receiving cefprozil and finally at the end visit. In vitro susceptibility tests of cefprozil to isolated pathogens were done by disc diffusion method, and in vitro susceptibility tests of cefaclor and cefixime to isolated pathogens were simultaneously performed. Results : Bacterial pathogens[S. pneumoniae(10), H. influenzae(5), S. aureus(2), M. catarrhalis(1) and Group A stretococcus(1)] were isolated from 19 patients. Clinically, all patients had history of abrupt high fever except one. Tympanic perforation was dominant in pathogens isolated cases, and otalgia was significantly developed in non-pathogens isolated cases. The ages of pathogens isolated cases were usually below 2 years. Eighty four point nine percent of the patients including two cases with isolation of intermediate resistant S. pneumoniae were clinically improved. Antimicrobial in vitro activity to S. pneumoniae of cefprozil were superior than that of cefacor and cefixime. Conclusion : We confirm that bacteria has the causative role in about 60% cases, and S. pneumoniae is the most common pathogen. Clinically, there were some differences in symptoms, signs and ages between pathogens isolated and non-pathogens isolated cases. The clinical responses of cefprozil in our patients revealed similar outcomes to other countries. And we reconfirm that cefprozil may be clinically effective in cases of AOM due to intermediate resistant S. pneumoniae.

• Clinical and Experimental Pediatrics
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• v.50 no.3
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• pp.284-291
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• 2007

Purpose : Theophylline has recently been reported to have concurrent anti-inflammatory effects at low therapeutic plasma concentrations which are below the doses at which significants, clinically useful bronchodilatation is evident. Sustained-release formulation in capsule and dry syrup forms were developed to reduce its adverse effects and improve its clinical effects. We compared the therapeutic effects of theophylline dry syrup and capsules in children with mild asthma. Methods : Ninety children with mild asthma were randomized to receive either theophylline dry syrup (n=44) or theophylline capsules (n=46); 4 mg per kilogram of body weight, twice a day, for 12 weeks. Baseline and serial measurements of daytime and nighttime asthma symptom score were performed. Compliance scores, drug swallowing scores, and drug usability scores were measured every 4 weeks. Each scoring was rated on a scale of 0-4. Serum theophylline concentration were measured at 4 and at 12 weeks. To examine the anti-inflammatory effect of theophylline on asthma, Serum eosinophilic cationic protein as a marker of airway inflammation caused by eosinophil was measured 12 weeks pre- and post-administration. Results : The daytime and nighttime asthma symptom scores of the two groups after 4 weeks significantly improved over the baseline score. Daytime and nighttime asthma symptom scores in the dry syrup group were statistically lower at all time points except for the nighttime symptom scores at 4 weeks. Compliance scores, drug swallowing scores, and drug usability scores in the dry syrup group were significantly higher at the end time point. Only in the dry syrup group was the serum ECP at the end time point statistically lower than baseline. Conclusion : Low-dose sustained-release theophylline may be safe and effective in bronchial asthma and this effect may be mediated by its anti-inflammatory action mechanisms. Especially, when used in children with asthma, dry syrup formulation is recommended because of its higher compliance than capsule formulation.

• Journal of the Korean Society of Radiology
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• v.85 no.3
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• pp.618-630
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• 2024

Purpose To compare the efficacy and safety of radiofrequency ablation (RFA) and ethanol ablation (EA) followed by RFA in treating mixed cystic and solid thyroid nodules. Materials and Methods We included 243 nodules from 243 patients who underwent RFA for mixed cystic and solid benign nodules. The nodules were divided into two groups (RFA alone and EA + RFA). We evaluated volume reduction rate (VRR), therapeutic success rate, improvement in symptomatic and cosmetic issues, complications, and adverse effects. Results The RFA group included 204 patients, and the EA + RFA group included 39 patients. The long-term success rates in the RFA only and EA + RFA groups were 90.2% and 97.4%, respectively. The mean VRR at the last follow-up in the RFA and EA + RFA groups were 81.6% and 87.2%, respectively. Therapeutic results were similar in both groups at the last followup. Cosmetic and symptomatic problems markedly improved in both groups. No major complications were observed. Conclusion Both RFA alone and EA + RA are safe and effective methods for treating mixed cystic and solid thyroid nodules, although EA + RFA is slightly more effective.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.67-72
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• 2008

Purpose : In this study, we retrospectively analyzed the clinical outcomes of patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) grafted from HLA-matched parents. Methods : Seven children with acute leukemia (4 acute lymphoblastic leukemia, 3 acute myeloid leukemia) in first complete remission received allogeneic HSCT from their respective parents at the St. Marys Hospital between April, 1999 and October, 2005. The median age of patients at transplantation was 5 years (range, 1-11 years; 2 male, 5 female) and the median age of donors was 35 years (range, 30-41 years; 5 male, 2 female). We investigated the clinical outcomes such as engraftment, acute and chronic graft-versus-host disease (GVHD), transplant-related morbidity and mortality, relapse and survival. Results : Median time from transplantation to last follow-up was 69.5 months (range, 18.8-96.5 months). All patients were successfully engrafted, with a median time of 11 days (range, 10-16 days) and 26 days (range, 13-39 days) for neutrophil and platelet recovery, respectively. Grade II acute GVHD occurred in 3, and grade III acute GVHD in 1 of 7 recipients. Extensive chronic GVHD developed in 2, and limited chronic GVHD in 1 of 7 recipients. Death from transplant-related complications occurred in 1, and relapse occurred in 1 of 7 recipients. Estimated 5-year overall survival was $83{\pm}15%$. Conclusion : The clinical outcomes of recipients who underwent HSCT from HLA-matched parents were comparable to those of patients who received HSCT grafted from HLA-matched sibling donors in childhood leukemia. HLA typing of parents, as well as siblings will increase the likelihood of finding an HLA-matched family donor for patients who need HSCT.

• Clinical and Experimental Pediatrics
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• v.50 no.11
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• pp.1061-1066
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• 2007

Purpose : Early identification of developmental disabilities allows intervention at the earliest possible point to improve the developmental potential. The Ages and Stages Questionnaire (ASQ), a parent- completed questionnaire, can be used as a substitute for formal screening tests. The purpose of this study was to evaluate the validity of the Korean version of the ASQ (K-ASQ) as a screening tool for detecting developmental delay of young Korean children in the setting of a busy pediatric outpatient clinic. Methods : Parents completed the K-ASQ in the waiting room of the pediatric outpatient clinic of St. Mary's Hospital, Catholic University Medical College. Out of 150 completed the ASQ, 67 who were born term and had no previous diagnosis of developmental delay, congenital anomalies, or neurological abnormalities were enrolled. The cut-off values of less than 2 standard deviations (SD) below the mean for the ASQ were used to define a "fail", and children who failed in one or more domains tested were classified as "screen-positive". Diagnosis of developmental delay was made when the developmental indices fell below -1 SD of the Bayley Scales of Infant Development-II. Results : (1) The mean age of children was $16.4{\pm}7.4$ months. Ten children (14.9%) were small-for- gestational age infants. The mean birth weight and gestational age were $3.1{\pm}0.6kg$ and $38.8{\pm}1.4$ weeks. Nine children (13.4%) were twins and 33 (49.0%) were male. The mean maternal education in years was $13.6{\pm}2.4$, and 31.3% had full-time jobs. The time for completing the ASQ was $10.2{\pm}3.0$ minutes. (2) Seventeen children (25.4%) were classified as screen-positive, four of them were delayed in development. Among eight children diagnosed with developmental delay, four were screen-positive and the other four were screen-negative by the ASQ. (3) The test characteristics of the ASQ were as follows: sensitivity (50.0%); specificity (78.0%); positive predictive value (23.5%); negative predictive value (92.0%). Conclusion : The high negative predictive value of the K-ASQ supports its use as a screening tool for developmental delay in the setting of a pediatric outpatient clinic.

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1348-1353
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• 2006

Purpose : The reticuloendothelial system is composed of sinusoidal capillaries, through which even large protein molecules are freely movable between plasma and interstitial space, including the lymphatic system. Therefore, high-dose intravenous immunoglobulin (IVIG) would cause a redistribution of proteins between two compartments. To investigate this hypothesis, we measured plasma protein and lipid levels in patients with Kawasaki disease before and after high-dose IVIG treatment. Methods : Thirty four children with Kawasaki disease who had complete responses to high-dose IVIG treatment (1 g/kg/day for two consecutive days), were analyzed. Before and after the administration of IVIG, serum analyses were performed for such parameters as total protein, albumin, ${\gamma}$-globulins (IgG, IgM, IgA), ${\alpha}1-$, ${\alpha}2-$, and ${\beta}-$ globulin fractions, and lipid profiles (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride). Results : The levels of ${\gamma}$-globulins including IgG, IgM, IgA were significantly increased, and IgG was increased by $1,779{\pm}304mg/dL$ after two-dose of IVIG infusion. The levels of albumin, ${\alpha}1-$, ${\alpha}2-$, and ${\beta}$ globulin fractions were significantly decreased by 18 percent, 24 percent, 19 percent and 12 percent, respectively. HDL-cholesterol level was significantly decreased by 20 percent, while LDL-cholesterol and triglyceride levels were significantly increased by 21 percent and 50 percent, respectively. The total cholesterol level was not changed. Conclusion : High-dose IVIG treatment decreased the levels of a variety of proteins except immunoglobulins, and the increase of IgG after IVIG treatment was lower than expected. Our results suggest that a part of infused IVIG and plasma proteins, including etiologic proteins for Kawasaki disease, may be distributed to the extravascular compartments. The rapid improvement of symptoms induced by IVIG in Kawasaki disease might be explained by this mode of action of IVIG.

• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1217-1224
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• 2007

Purpose : Due to its high potency against leukemic blasts, our institution has opted for the use of dexamethasone during acute lymphoblastic leukemia (ALL) remission induction, but in our most recent treatment protocol, CMCPL-2005, we shortened the length of steroid treatment from 4 to 3 weeks. We compared both the rates of remission induction and significant complications observed during induction with CMCPL-2005, with those noted for our previous protocol, CMCPL-2001. Methods : We retrospectively reviewed the records of patients diagnosed with ALL from January, 2001 to December, 2006 at the Department of Pediatrics, St. Mary's Hospital, the Catholic University of Korea. Data concerning age, sex, WBC count at diagnosis, immunophenotype, cytogenetic traits, and risk group were collected for each patient. Results of remission induction treatment were compared between the two patient groups. Infection and other major complications resulting from treatment were investigated according to NCI toxicity criteria. Results : A total of 141 and 88 patients received remission induction under CMCPL-2001 and CMCPL-2005 respectively. In the CMCPL-2001 group, 136 (96%) achieved complete remission while 82 (93%) achieved CR in the CMCPL-2005 group. Patients in the CMCPL-2005 group were more likely to undergo remission induction without experiencing major complications. However, with regards to steroid related toxicities such as infection, no significant differences were noted. Conclusion : We shortened the length of steroid administration from four to three weeks, yet found the remission induction rate to be comparable to that of our previous regimen. However, rates of steroid related toxicities such as infectious complications remain unchanged despite shortened exposure to dexamethasone.

• Childhood Kidney Diseases
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• v.13 no.2
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• pp.138-145
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• 2009

Purpose : This study was aimed to evaluate the changes of immunologic parameters during hospitalization, and the relationship between IgG and other laboratory or clinical indices in patients with acute poststreptococcal glomerulonephritis (APSGN). Methods : We reviewed the medical charts of 36 children with APSGN who showed ASO titer>250 Todd U/L and C3<70 mg/dL. We evaluated the levels of IgG and other laboratory parameters including C3 and ASO at admission and at discharge (14 cases). Results : The mean age of APSGN patients was $7.5{\pm}2.6$ year of age, and male-to-female ratio was 2.3:1. At presentation, hypertension (systolic blood pressure>125 mmHg), gross hematuria, and weight gain were observed in 27.8% (10/36), 80.1% (29/36), and 80% (24/30) of the patients, respectively. The mean IgG level was $1,432{\pm}322$ mg/dL ($1,025{\pm}234$ mg/dL in control group, P<0.001), and C3 and ASO levels were $26.1{\pm}16.1$ mg/dL and $1,068{\pm}730$ Todd U, respectively. There were no correlation between IgG level and the levels of any of the parameters analyzed (ASO, C3, BUN, creatinine and white blood cell count), and the severity of the disease assessed by the weight-change during admission. The patients aged<6 years of age (10 cases) had less degree of the weight-change, compared to those of the patients aged>8 years of age (15 cases) (-0.6% vs. -5.7%, P=0.01). The IgG and ASO levels did not change, but C3 (P=0.001) and IgM (P=0.02) levels increased during admission. Conclusion : Increased IgG and ASO levels in APSGN did not change, but C3 level increased during admission. IgG level was not correlated with other laboratory parameters (ASO and C3) and the severity of the disease. Younger children seem to have less severe clinical course compare to older children. With our hypothetic pathogenesis of APSGN, further studies are needed to resolve the pathogenesis of the disease including the increase of IgG.