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Improvement of the Dose Calculation Accuracy Using MVCBCT Image Processing (Megavoltage Cone-Beam CT 영상의 변환을 이용한 선량 계산의 정확성 향상)

  • Kim, Min-Joo;Cho, Woong;Kang, Young-Nam;Suh, Tae-Suk
    • Progress in Medical Physics
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    • v.23 no.1
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    • pp.62-69
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    • 2012
  • The dose re-calculation process using Megavoltage cone-beam CT images is inevitable process to perform the Adaptive Radiation Therapy (ART). The purpose of this study is to improve dose re-calculation accuracy using MVCBCT images by applying intensity calibration method and three dimensional rigid body transform and filtering process. The three dimensional rigid body transform and Gaussian smoothing filtering process to MVCBCT Rando phantom images was applied to reduce image orientation error and the noise of the MVCBCT images. Then, to obtain the predefined modification level for intensity calibration, the cheese phantom images from kilo-voltage CT (kV CT), MVCBCT was acquired. From these cheese phantom images, the calibration table for MVCBCT images was defined from the relationship between Hounsfield Units (HUs) of kV CT and MVCBCT images at the same electron density plugs. The intensity of MVCBCT images from Rando phantom was calibrated using the predefined modification level as discussed above to have the intensity of the kV CT images to make the two images have the same intensity range as if they were obtained from the same modality. Finally, the dose calculation using kV CT, MVCBCT with/without intensity calibration was applied using radiation treatment planning system. As a result, the percentage difference of dose distributions between dose calculation based on kVCT and MVCBCT with intensity calibration was reduced comparing to the percentage difference of dose distribution between dose calculation based on kVCT and MVCBCT without intensity calibration. For head and neck, lung images, the percentage difference between kV CT and non-calibrated MVCBCT images was 1.08%, 2.44%, respectively. In summary, our method has quantitatively improved the accuracy of dose calculation and could be a useful solution to enhance the dose calculation accuracy using MVCBCT images.

Intensity Modulated Radiation Therapy Commissioning and Quality Assurance: Implementation of AAPM TG119 (세기조절방사선치료(IMRT)의 Commissioning 및 정도관리: AAPM TG119 적용)

  • Ahn, Woo-Sang;Cho, Byung-Chul
    • Progress in Medical Physics
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    • v.22 no.2
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    • pp.99-105
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    • 2011
  • The purpose of this study is to evaluate the accuracy of IMRT in our clinic from based on TG119 procedure and establish action level. Five IMRT test cases were described in TG119: multi-target, head&neck, prostate, and two C-shapes (easy&hard). There were used and delivered to water-equivalent solid phantom for IMRT. Absolute dose for points in target and OAR was measured by using an ion chamber (CC13, IBA). EBT2 film was utilized to compare the measured two-dimensional dose distribution with the calculated one by treatment planning system. All collected data were analyzed using the TG119 specifications to determine the confidence limit. The mean of relative error (%) between measured and calculated value was $1.2{\pm}1.1%$ and $1.2{\pm}0.7%$ for target and OAR, respectively. The resulting confidence limits were 3.4% and 2.6%. In EBT2 film dosimetry, the average percentage of points passing the gamma criteria (3%/3 mm) was $97.7{\pm}0.8%$. Confidence limit values determined by EBT2 film analysis was 3.9%. This study has focused on IMRT commissioning and quality assurance based on TG119 guideline. It is concluded that action level were ${\pm}4%$ and ${\pm}3%$ for target and OAR and 97% for film measurement, respectively. It is expected that TG119-based procedure can be used as reference to evaluate the accuracy of IMRT for each institution.

A Study of Energy Dependency in Intensity Modulated Radiation Therapy of Lung Cancer (폐암환자의 세기조절방사선치료에서 에너지에 따른 선량분포 특성 비교)

  • Kim, Sung-Kyu;Kim, Myung-Se;Yun, Sang-Mo
    • Progress in Medical Physics
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    • v.19 no.3
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    • pp.191-199
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    • 2008
  • PTV considered for the energy, dose distribution exposed to lung and spinal cord, and the characteristic of DVH(Dose Volume Histogram) were compared and investigated by planning the intensity modulated radiation therapy (IMRT) using the photon energies of 6 MV and 10 MV according to tumor location like as the anterior, middle, and posterior regions of lung, and the mediastinum region in lung cancer patients. Our institution installed the linear accelerator (Varian 21 EX-s, USA) equipped with 120 multileaf collimator for lung cancer patients, which is producing the photon energies of 6 MV and 10 MV, and radiation therapy planning was performed with ECLIPSE system (Varian, SomaVision 6.5, USA), which support inverse treatment planning. The tomographic images of 3 mm slice thickness for lung cancer patients were acquired using planning CT, and acquired tomographic images were sent to the Varis system, and then treatment planning was performed in the ECLIPSE system. The radiation treatment planning of the IMRT was processed from various angles according to the regions of the tumor, and using various beam lines according to the size and location of the tumor. The investigation of the characteristic of dose distributions for the energy of 6 MV and 10 MV according to tumor locations in lung cancer patients resulted that the maximum dose of 10 MV energy was 1.2% less than that of 6 MV energy without depending on the tumor location of lung cancer, and the reduction effects of MU were occurred from 10 to 25 MU. Radiation dose exposed to the lung satisfied the less 30% of V20, however radiation dose in 6 MV energy was from 0.1% to 0.5% less than that in 10 MV energy. Radiation dose exposed to the spinal cord for 6 MV energy was from 0.6% to 2.1% less than that for 6 MV energy.

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A multicenter clinical study of installed US II Plus/GS II Osstem implants after bone graft (골 이식술 후 Osstem Implant (US II Plus/GS II)의 다기관 임상연구)

  • Chung, Kwang;Oh, Chul-Jung;Ha, Ji-Won;Kook, Min-Suk;Park, Hong-Ju;Oh, Hee-Kyun;Kim, Su-Gwan;Kim, Young-Kyun;Kim, Woo-Cheol
    • The Journal of the Korean dental association
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    • v.50 no.12
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    • pp.743-754
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    • 2012
  • urpose : The purpose of this study was to evaluate the US II plus/GS II Osstem$^{(R)}$ implants through the study for the clinical success rate during the installation of the Osstem¢Á implants after bone graft. Materials and Methods : This study was researched in the 4 medical institutions: Chonnam National University, Chosun University, Bundang Seoul National University Hospital, and FM dental clinic from May, 2002 to September, 2009. Based on the total number of 60 patients whose treatment was the installation of the US II plus/GS II Osstem¢Á implants after bone graft, we evaluated success rate of implants. We analysis the distribution of patient's age and gender, edentulous area, bone type, fixture length and diameter, installation and loading time, donor site, bone graft material and method, antagonistic teeth, and survival and success rate. From these analyses we got the following results. Results : 1. In this study, the total number of patients who have been installed with US II plus implant was 27, and total of 52 implants were installed. The average age was 38.9, with 16 male, and 11 female patients. 2. The total number of patients who have been installed with GS II implant was 33, and total of 54 implants were installed. The average age was 49.7, with 24 male, and 9 female patients. 3. As for bone graft method, either autogenous bone or a mix of autogenous and heterogenous bone was used(88.4%) for US II plus. Chin, iliac, and Maxillary tuberosity were the donor sites for autogenous bone graft, and onlay method of bone graft was performed. 4. Allogenic bone or a mix of autogenous and heterogenous bone was used(77.8%) for GS II. Chin, ramus, and tibia were the donor sites for autogenous bone graft, and GBR method of bone graft was performed. 5. The duration from the installation of implants to setting of final prosthesis was average of 16 months and 10 months for US II plus and GS II respectively. Also, the final follow up period was average of 31 months and 28 months respectively. During this period, one GS II implant was removed from 1 patient due to failure of early osteointegration. 6. The survival rates were 100% and 98.1%, and success rates were 94.2% and 94.4% for US II plus and GS II implant respectively. Conclusion : On the evaluation of our clinical study, both US II plus and GS II Osstem¢Á implants showed the excellent clinical results after bone graft.

Analysis of Telephone Counseling Service on Child Health (전화 아기건강상담을 통해 나타난 우리나라 어머니들의 육아문제 분석)

  • Song Ji-Ho;Han Kyung-Ja;Oh Ka-Sil;Cho Kyoul-Ja;Lee Ja-Hyung;Park Eun-Sook;Cho Kap-Chul;Tak Young-Nan;Ahn Young-Mee
    • Child Health Nursing Research
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    • v.7 no.2
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    • pp.245-257
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    • 2001
  • This study analyzed the services as operated by the Child Health Telephone Service Center. The Center is a toll free service operated as part of the community services of the Korean Academic Society of Child Health Nursing. The aim of the study was to describe the concerns of child caregivers regarding child health care as discussed during telephone counseling. Specific objectives were as follows: 1. To analyze the activities of the Center. 2. To describe the characteristics of caregivers who made phone calls for counseling services and also the characteristics of their children. 3. To analyze the content of the counseling sessions. 4. To analyze counseling content according to the characteristics of the caregivers and their children. Data used for the study were obtained from the counseling records for the period from Sept. to Dec. 1999, as kept by the three counselors at the Center. The total number of calls was 8,261 and that consisted of 15,150 questions. The total questions were merged into 13,236 by eliminating those questions which overlapped or were of similar content. The final 13,236 questions were used for the final analyses. Almost of the callers (98.4%) were mothers. Among them 89.6% were between 25 and 35 years of age. Geographical distribution of the callers covered the whole nation. The largest numbers who made the calls were from the Seoul metropolitan area (36%), followed by 28% from Kyung Gi Province, and 20% were from the Kyung Sang area. Among 8,261 callers, 72.8% were first users. Sex of the babies and children in question for counseling was about even for males and females and ages ranged from one month to six years. The largest group (62.5%) was the less than six month age group. The finalized 13,236 questions/problems were categorized into 11 problem areas. They were in order of frequency, physical problems, feedings and nutrient concerns, information on child rearing, growth and development, guidance on utilization of child care facilities, elimination problems, sleeping concerns, immunization related concerns, behavior problems, injury and accidents, and safety measures. The most frequent problems for counseling were physical signs and symptoms (27.3%), followed by feeding and nutrients, information on child rearing, and growth and development. Of physical problems, abnormal gastrointestinal signs and symptoms were the most frequent concern and skin problems were next at 25% and 23.3% respectively. Loose bowels, vomiting and constipation were the most frequent gastrointestinal problems. Atopic dermatitis had the highest frequency at 53.3% with diaper rash being the second highest among the skin problems. About 80% of the growth and developmental category were physical development concerns related to physiological, body growth, and motor and sensory development. This study constitutes the activity report for the first year of the Center. The findings correspond with literature reports on child health problems and parents educational needs. One recommendation from this study is that since the services of the Center are carried out only by telephone, the psychology of the counselees and the counselor relationship must be considered for better services.

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Effect of Freezing and Thawing Condition on the Physical Characteristics of Blanched Bean Sprouts as Home Meal Replacement (냉.해동 조건에 따른 간편편이식 콩나물의 물리적 품질 변화)

  • Jang, Min-Young;Jung, You-Kyoung;Min, Sang-Gi;Cho, Eun-Kyung;Lee, Mi-Yeon
    • Culinary science and hospitality research
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    • v.20 no.6
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    • pp.235-244
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    • 2014
  • The purpose of this study was to investigate the effect of freezing and thawing rate on the physical properties of soybean sprouts to improve the quality of processed soybean sprouts during distribution and storage. Cooked soybean sprouts were frozen by air-blast freezing (ABF) system at $-45^{\circ}C$ or natural air convection freezing (NCF) system at $-24^{\circ}C$, then thawed using microwave oven by varying output power (0, 400, 800 and 1,000 W) until $75^{\circ}C$. The quality of soybean sprouts was measured by the water content, hardness and springiness. In addition, the internal microstructure of soybean sprouts was observed by optical microscope. For results, water content of soybean sprouts thawed by 1,000 W in a microwave showed the lowest value after natural air convection freezing. Springiness of soybean sprouts thawed by all amounts of output power was decreased in comparison with control. Hardness was increased only in soybean sprouts thawed by 1,000 W after air-blast freezing. However the gaps between springiness and hardness were relatively small with control at 1,000 W thawing, after air-blast freezing. Internal microstructure of the soybean sprouts was more damaged as freezing and thawing time were increased. In conclusion, high freezing and thawing rate might improves the quality of soy bean sprout, and IQF freezing and 1,000 W of microwave thawing appears to be the optimum condition for frozen HMR production. From the results freezing and thawing process parameters might can be use as quality control parameters as various type of sprout products processing.

Diagnostic Value of Serum CYFRA 21-1 in Lung Cancer (폐암에서 혈중 CYFRA 21-1의 진단적 가치)

  • Yoon, Hyun-Dae;Kim, Ki-Deok;Chung, Jin-Hong;Lee, Hyung-Woo;Lee, Kwan-Ho;Lee, Hyun-Woo;Cho, Ihn-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.2
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    • pp.149-155
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    • 1995
  • Background: Cytokeratin 19 is 40KD acidic molecule whose distribution is restricted to simple or pseudo-stratified epithelia, such as the epithelial layer of the bronchial tree. Immunohistochemical study have shown that cytokeratin 19 is overexpressed in lung carcinoma tissue. An immunoradiometric assay, CYFRA 21-1 has been developed using two monoclonal antibody, BM 19-21 and KS 19-1, reactive to different epitopes on cytokeratin 19. We studied the diagnostic value of CYFRA 21-1 in lung cancer. Method: The serum CYFRA 21-1 level using immunoradiometric kit(ELSA-CYFRA 21-1) was measured in 54 patients who admit to Yeungnam University Hospital from April, 1993 to August, 1994. Lung cancer group was 39 primary lung cancer patients(19 patients with squamous cell carcinoma, 11 patients with adenocarcinoma and 9 patients with small cell carcinoma). Control group was 15 patients with non malignant lung diseases(8 patients with pulmonary tuberculosis, 3 patients with chronic obstructive pulmonary disease, 2 patients with pneumonia and 2 patients with chronic obstructive pulmonary disease combined with pulmonary tuberculosis). Results: The mean serum value of CYFRA 21-1 was $20.2{\pm}4.7ng/ml$ in squamous cell carcinoma, $7.2{\pm}1.6ng/ml$ in adenocarcinoma and $15.5{\pm}4.7ng/ml$ in non-small cell lung cancer. The serum value of CYFRA 21-1 in control group was $1.7{\pm}0.5ng/ml$. All of the serum values of 3 histologic types were significantly higher than that of control group(p<0.01). The serum value of CYFRA 21-1 of squamous cell carcinoma was significantly higher than that of adenocarcinoma(p <0.05). Serum value of CYFRA 21-1 in small cell lung cancer was $2.9{\pm}0.9ng/ml$ and not significantly different compared with control group. Using cut off value of 3.3ng/ml, sensitivity and specificity was 11.1%, 65.2% in small cell lung cancer, 70.0%, 62.5% in non-small cell lung cancer, 73.7%, 75% in squamous cell carcinoma and 63.6%, 78.9% in adenocarcinoma, respectively. Conclusion: The serum levels of CYFRA 21-1 may be useful in diagnosis of non-small cell lung carcinoma, especially in squamous cell carcinoma with its high specificity.

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A Study on Clinical Progress of the Metastatic Adenocarcinoma of Pleura (전이성 흉막선암의 임상 경과에 관한 연구)

  • Yang, Seong-Wook;Lee, Tae-Kwan;Lee, Tae-Heon;Cho, Deok-Su;Baek, Hyeon-Seon;Kim, Ji-Young;Lee, Hye-Kyung;Kim, Kwi-Wan
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.2
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    • pp.156-164
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    • 1995
  • Background: We had undergone this study to investigate clinical progress of this disease and to decide the role of aggressive diagnostic approaches, the efficacy of treatments and prognoses. Methods: A retrospective study was done on 113 patients who had been diagnosed to metastatic adenocarcinoma of pleura by pleural fluid cytology(106 cases) or pleural needle biopsy(22 cases), at Presbyterian Medical Center, from Jan. 1990 to Dec. 1994. Results: 1) The patients were composed of 59 males(52.2%) and 54 females(47.8%), and the mean age distribution was $57.4{\pm}12.1$ years. 2) The site of origin was lung cancer 46.9%(53/113), stomach cancer 20.4%(23/113), breast cancer 11.5%(13/113), and unknown primary site 6.2%(7/113 cases), as a whole. In male, lung cancer was 55.9%(33/59), stomach cancer was 28.8%(17/59), and in female, lung cancer was 37%(20/54), breast cancer was 24.1%(13/54) of cases. 3) The cardinal symptoms were dyspnea(69%), cough(61%), chest pain(50%), weight loss(50%), anorexia(49%), sputum(43%), malaise(30%). 4) The pleural fluid findings were exudative in 94.4%(102/108), serosanguinous or bloody in 36~53%, unilateral involvement in 74.3%(84/113) of cases, and lymphocyte predominance($71{\pm}27%$) in differential count of WBC. 5) CEA levels in pleural fluid or plasma were over 10ng/ml in 60.6%(40/66), and ADA levels in pleural fluid were under 40U/L in 95%(57/60) of cases. 6) The patients were managed by various methods, but the efficacy of treatment was uncertain. 7) The mean survival time was $12.7{\pm}13.5$ weeks. Conclusion: It seems to be no effective treatment methods yet and the prognosis was very poor in this disease, so the objectives of diagnostic approaches and treatment methods should be directed to early diagnosis, treatment and prevention of curable disease. And we must make our best endeavors to lengthen the survival time and improve the quality of patients' life.

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Pulmonary Tuberculosis Mimicking Pneumonia on CT : Retrospective Analysis of Clinical and CT Features (전산화단층촬영에서 폐렴양 소견을 보였던 폐결핵: 임상 및 전산화단층촬영 소견의 후향적 고찰)

  • Paeng, Mi Hye;Kim, Yoo Kyung;Shim, Sung Shin;Chang, Jung Hyun;Lee, Jin Hwa;Kwag, Hyon Joo
    • Tuberculosis and Respiratory Diseases
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    • v.55 no.1
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    • pp.31-40
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    • 2003
  • Background : A CT scan is a useful modality for the diagnosis and evaluation of disease activity in patients with pulmonary tuberculosis. However, the CT diagnosis of pulmonary tuberculosis is sometimes difficult in patients with an atypical CT pattern, especially with lobar consolidation mimicking pneumonia. The aim of this study was to evaluate the clinical and CT features of pulmonary tuberculosis, simulating pneumonia, from a CT scan. Materials and Methods : The clinical and CT features in 21 patients, where the CT diagnosis was pneumonia, or the CT differential diagnosis included pneumonia, were retrospectively analyzed. Results : Of the 21 patients, 6 were immunocompromised, 15 presented with fever or leukocytosis and 15 showed positive sputum smear test for acid fast bacilli. Also, 17 of the 21 patients showed a positive sputum culture test. On the CT scan, consolidation was noted in all patients (100%), volume loss of the involved lobe or segment in 12 (57%), bronchogenic spread in 15 (71%), a cavity in 7 (33%) and bronchial wall thickening also in 7 (33%). The location of the consolidation revealed a relatively even distribution, with no specific predilection site. The other associated pulmonary diseases included ARDS, bronchiectasis, severe pulmonary emphysema, idiopathic pulmonary fibrosis and pulmonary alveolar proteinosis. Conclusion : In the immunocompromised patients, or patients with an underlying pulmonary disease, whose CT scans showed pulmonary consolidation, especially in association with findings of bronchogenic spread, a cavity or bronchial wall thickening, meticulous examination for pulmonary tuberculosis is recommended.

Analysis of HLA in Patients with Obstructive Sleep Apnea Syndrome (폐쇄성 수면무호흡증후군 환자에서 사람백혈구항원 분석)

  • Lee, Sang Haak;Kim, Chi Hong;Ahn, Joong Hyun;Kang, Ji Ho;Kim, Kwan Hyoung;Song, Jeong Sup;Park, Sung Hak;Moon, Hwa Sik;Choi, Hee Baeg;Kim, Tai Gyu;Choi, Young Mee
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.3
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    • pp.298-305
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    • 2005
  • Background : Obstructive sleep apnea syndrome (OSAS) is believed to have multifactorial causes. The major risk factors for OSAS are obesity, narrowed upper airways, and abnormal cranial-facial structures. A genetic basis for OSAS has been also suggested by reports of families with many members affected. This study analyzed the HLA typing in patients with OSAS to determine the possible role of genetics in OSAS. Methods : Twenty-five Korean patients with OSAS (1 woman and 24 men; age range 30-66 years) were enrolled in this study. A diagnosis of OSAS was made using full-night polysomnography. The control group consisted of 200 healthy Korean people. Serologic typing of the HLA-A and B alleles was performed in all patients using a standard lymphocyte microcytotoxicity test. Analysis of the polymorphic second exons of the HLA-DRB1 gene was performed using a polymerase chain reaction-sequence specific oligonucleotide probe. Results : The allele frequency of HLA-A11 was significantly lower in patients with OSAS compared with the controls (p<0.05). The HLA-B allele frequencies in the patients and controls had a similar distribution. Analysis of the HLADRB1 gene polymorphisms showed an increased frequency of DRB1*09 in the OSA patients compared with the controls (p<0.05). When the analysis was performed after dividing the OSAS patients according to the severity of apnea, the allele frequency of HLA-DRB1*08 was significantly higher in the severe OSA patients (apnea index >45) than in the controls (p<0.05). Conclusion : This study revealed an association between OSAS and the HLA-A11 and DRB1*09 alleles as well as association between the disease severity and the HLA-DRB1*08 allele in Korean patients. These results suggest that genetics plays an important role in both the development and the disease severity of OSAS.