• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.273-280
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• 2001

Objectives : The purpose of this study is to assess the long-term outcome and delayed complications of Gamma Knife radiosurgery for low grade glioma(LGG). Methods : Among 31 patients of LGG who had been treated by using Leksell Gamma Knife between March 1992 and December 1996, we could follow up more than 5 years(range 5-9 years) in 17 patients and evaluated their clinical feature, changes of tumor volume and post-radiosurgical complications. Results : During the mean follow-up period of 7.6 years, the tumor was decreased in 5 patients(29.4%), unchanged in 4(23.5%), increased in 4(23.5%) and recurred in 4(23.5%). The tumor control rate was 52.9%(9/17). We have experienced eighteen postradiosurgical complications in 10 patients(58.8%). Early complication was none and delayed complications included radiation necrosis with cyst in ten cases, bleeding in five, radiation-induced edema in one and malignant transformation in one. Two patients ultimately died as a result of tumor progression during the follow-up period. The mortality rate was 11.7%. Conclusion : Gamma Knife radiosurgery may be useful as an adjunctive therapy for small volume, deep-seated LGG. Although radiosurgery can effectively prevent growth of solid tumor, several delayed complications such as radiation necrosis, cyst formation, bleeding or malignant transformation can develop during the long-term followup period. Because of the possible slow growth rate of LGG and development of the delayed complications, the long-term efficacy of radiosurgery requires further analysis.

• Korean Journal of Clinical Oncology
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• v.14 no.2
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• pp.83-88
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• 2018

Purpose: Double primary colorectal cancer (CRC) and gastric cancer (GC) represent the most common multiple primary malignant tumors (MPMT) in Korea. The recognition and screening of hidden malignancies other than the primary cancer are critical. This study aimed to investigate the clinicopathologic characteristics and survival rates in patients with synchronous or metachronous double primary CRC and GC. Methods: Between January 1994 and May 2018, 11,050 patients were diagnosed with CRC (n=5,454) or GC (n=5,596) at Gil Medical Center. MPMT and metastatic malignant tumors were excluded from this study. A total of 103 patients with double primary CRC and GC were divided into two groups: the synchronous group (n=40) and the metachronous group (n=63). The incidence, clinicopathologic characteristics, and survival rate of the two groups were analyzed. Results: The incidence of synchronous and metachronous double primary CRC and GC was 0.93%. Double primary CRC and GC commonly occurred in male patients aged over 60 years with low comorbidities and minimal previous cancer history. There were significant differences between the synchronous and metachronous groups in terms of age, morbidity, and overall survival. Metachronous group patients were 6 years younger on average (P=0.009), had low comorbidities (P=0.008), and showed a higher 5-year overall survival rate (94.8% and 61.3%, P<0.001) in contrast to synchronous group. Conclusion: When primary cancer (CRC or GC) is detected, it is important to be aware of the possibility of the second primary cancer (GC or CRC) development at that time or during follow-up to achieve early detection and better prognosis.

• Phonetics and Speech Sciences
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• v.14 no.4
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• pp.35-43
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• 2022

This paper studies how to improve the identification rate of laryngeal disability speech data by convolutional neural network (CNN) and machine learning ensemble learning methods. In general, the number of laryngeal dysfunction speech data is small, so even if identifiers are constructed by statistical methods, the phenomenon caused by overfitting depending on the training method can lead to a decrease the identification rate when exposed to external data. In this work, we try to combine results derived from CNN models and machine learning models with various accuracy in a multi-voting manner to ensure improved classification efficiency compared to the original trained models. The Pusan National University Hospital (PNUH) dataset was used to train and validate algorithms. The dataset contains normal voice and voice data of benign and malignant tumors. In the experiment, an attempt was made to distinguish between normal and benign tumors and malignant tumors. As a result of the experiment, the random forest method was found to be the best ensemble method and showed an identification rate of 85%.

• The Journal of the Korean bone and joint tumor society
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• v.9 no.2
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• pp.131-138
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• 2003

Purpose: We analyzed our malignant peripheral nerve sheath tumor (MPNST) cases to find out their oncologic results following by each treatment modalities. Materials and Methods: Thirty four patients with MPNST were registered in Korea Cancer Center Hospital from Feb. 1986 to Nov. 1996. Seventeen cases were male and 17, female. Average age was 41 years (range 18 to 74). Location of the tumor was as follows; 17 in lower extremity, 11 upper extremity, 4 trunk, and 2 retroperitoneum. Following the AJC classification, stage IA were 2 cases, stage IIA 2, stage IIB 6, stage III 16 and stage IV 8. Twenty six patients took operations and adjuvant chemotherapy and/or radiation therapy, 3 operation only and 3 adjuvant chemotherapy or radiation therapy. Average follow up period was 33.5 months (5.6 to 146.1). Kaplan-Meiyer method was done for survival curve, and log rank test for comparison analysis. Results: Fourteen cases were continuous disease free, 2 no evidence of disease, 2 alive with disease and 14 dead of disease states at final follow up. Actual 5-year and 10-year survival rates were 53.5%, 35.7%. Local recurrence rate after operation was 24.1%. 5-year survival rates of stage I/II/III were 100/85.7/55.9% and 2-year survival rate of stage IV was 14.3% (p=0.04). In 21 cases operated with stage II-III, wide margin (15cases) had 76.0% 5-year survival rate, and marginal or intralesional marigin (6cases) had 40.0%. The actual 5-year survival rate of the group which were done 4 or more cycles chemotherapy (8cases) was 71.4% and the actual 3-year survival rate less than 4cycles chemotherapy (6cases) was 83.3% (p=0.96). In 19 cases operated with stage II-III and which had no radiotherapy, marginal or intralesional margin (5cases) had 3 cases of local recurrences (60.0%), though wide margin (14cases) had 4 cases recurrences (28.6%). There was no local recurrence in 8cases which had pre-or post-operative radiotherapy. Conclusions: Surgical margin is an important factor in local recurrence. Resection margin has a tendency to influence the survival despite insufficient statistical significance. Conventional chemotherapy has no defnite statistical sigficance in the effect on local control and survival. Preoperative and postoperative radiotherapy has some positive effect on local control.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.251-258
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• 1998

Purpose : This study was performed to analyze the factors affecting local control in malignant tumors of the parotid gland treated with surgery and postoperative radiation. Materials and methods : Twenty-six patients were treated for malignant tumors of the parotid gland from 1986 to 1995 at Department of Therapeutic Radiology, Chonnam University Hospital. Age of the patients ranged from 14 to 72 years (median : 55 years). Histologically 10 patients of mucoepidermoid carcinoma, 7 of squamous cell carcinoma, 4 of acinic cell carcinoma, 4 of adenoid cystic carcinoma and 1 of adenocarcinoma were treated. Total parotidectomy was performd in 15 of 26 patients, superficial in 7, subtotal in 4. Facial nerve was sacrificed in 5 patients. Postoperatively 4 patients had residual disease, 4 had positive resection margin. Radiation was delivered through an ipsilateral wedged pair of photon in 11 patients. High energy electron beam was mixed with photon in 15 patients. Electron beam dose ranged from 900 cGy to 3800 cGy (median 1700 cGy). Total radiation dose ranged from 5000 cGy to 7560 cGy (median : 6020 cGy). Minimum follow-up period was 2 years. Local control and survival rate were calculated using Kaplan-Meier method. Generalized Wilcoxon test and Cox proportional hazard model were used to test factors affecting local control. Results : Five (19$\%$) of 26 patients had local recurrence. Five year local control rate was 77$\%$. Overall five year survival rate was 70$\%$. Sex, age, tumor size, surgical involvement of cervical lymph node, involvement of resection margin, surgical invasion of nerve, and total dose were analyzed as suggested factors affecting local control rate. Among them patients with tumor size less than 4 cm (p=0.002) and negative resection margin (p=0.011) were associated with better local control rates in univariate analysis. Multivariate analysis showed only tumor size factor is associated with local control rate (p=0.022). Conclusion : This study suggested that tumor size is important in local control of malignant tumors of parotid gland.

• Journal of Chest Surgery
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• v.36 no.3
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• pp.175-181
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• 2003

Primary chest wall tumors originate from soft tissue, bone or cartilage of the chest wall and it comprises 1∼2% of all primary tumors. Resection of tumor is often indicated for chronic ulceration or pain, and long-term survival might be achieved after surgery depending on the histology and the surgical procedure. Material and Method: Retrospective study of 125 primary chest wall tumors (86 benign, 39 malignant) operated between Sep. 1976 to Mar 2001 were reviewed and their clinical outcomes were analyzed. Follow-up data were collected at the outpatient clinic. Result: All patients with benign tumors were treated by excision without recurrence or death, and most malignancies were treated by wide resection. Malignant fibrous histiocytoma and chondrosarcoma constituted 46.2% of the malignant neoplasm. There was no operative death. The overall 3-year survival for patients with primary malignant neoplasm was 76.0%, and the 10-year survival was 60.5%. All deaths were disease-related and the tumor recurred in 11 patients. There was no significant difference in survival between patients with resection margins less than 4 cm and those with resection margins greater than 4 cm. Conclusion: Chest wall resection offers excellent results for benign chest wall tumors and substantial long-term survival for malignant diseases. Safe resection margin of 4 cm or more did not correlate with the survival rate although the tumor recurrence correlated with poor survival.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5709-5714
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• 2015

Aim: To assess the treatment outcome in patients with malignant skin melanoma and prognostic factors for distant metastases (DM), disease-free survival (DFS) and overall survival (OS). Materials and Methods: A retrospective analysis was conducted on 113 patients with malignant skin melanoma (60 females, 53 males, average age-55 years) who were treated surgically. Primary treatment consisted of local excision. In 12 cases, it was accompanied by lymph node excision. In 93 (82%) cases, radicalization was necessary, which was either local only (19 cases) or accompanied by lymph node surgery/biopsy (74 cases). Possible prognostic factors such as Clark's stage and Breslow's depth of invasion, ulceration, average tumor dimensions, lymph nodes metastases (pN+), gender, tumor location and primary excision margins were considered. Results: In 51 (45%) cases, treatment failure occurred. The 5-year DM rate was 47%, the 5-year DFS was 38%, and the 5-year OS was 56%. In the univariate analysis, the important factors with respect to at least one endpoint included Clark's stage, Breslow's depth of invasion, ulceration, average tumor dimensions, lymph nodes metastases, gender and primary tumor localization. The presence of metastasic nodes was the most important prognostic factor, with a 5-year DM rates of 30% for pN(-) and 76% for pN(+) and a 5-year DFS and OS of 56% and 76% for pN(-) and 13% and 24% for pN(+), respectively. The average tumor dimension was independently significant for DFS and OS, with 5-year rates of 69% and 80% for ${\leq}1cm$, 28% and 53% for 1-2 cm, and 18% and 30% for >2 cm, respectively. Tumor location was also significant for DM and OS, with 5-year rates of 69% vs 33% and 41% vs 66% for trunk vs other locations, respectively. Conclusions: The natural course of a malignant skin melanoma treated radically is disadvantageous, with unsuccessful outcome in nearly half of the cases. Common clinical factors, such as Clark's tumor stage, Breslow's depth of invasion and the presence of metastatic nodes, have high prognostic significance. The size and location of the primary lesion may be considered independent prognostic factors. The most important negative prognostic factor is the presence of metastatic regional lymph nodes. Only one quarter of patients with metastases in lymph nodes survive 5 years from primary surgery.

• Journal of Korean Neurosurgical Society
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• v.44 no.4
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• pp.222-227
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• 2008

Objective : Malignant gliomas are the most common primary cerebral neoplasms in adults. Despite multimodality treatments, the prognosis for patients with malignant glioma remains poor. However, recently, the effectiveness of concomitant chemoradiotherapy (CCRT) with temozolomide (TMZ) has been reported. We report for the first time preliminary results of the treatment with CCRT of newly diagnosed malignant gliomas in Korean people. Methods : Thirty-two patients over the age of 17 years with newly diagnosed and histologically confirmed high-grade gliomas (HGG), from June 2004 to August 2007 were the subjects of this study. There were 17 men and 15 women, with a median age of 53.5 years (range, 17-74). Pathologically, glioblastoma, anaplastic astrocytoma, anaplastic oligodendroglioma, and gliomatosis cerebri had been diagnosed in eighteen, eight, four, and two patients, respectively. These 32 patients were treated with CCRT with TMZ. Results : The median follow-up period was 12.5 months (range 3-48). At the time of this analysis, 13 patients died and three patients had been lost to follow-up. There was no mortality caused by drug toxicity. The median progression-free survival (PFS) of these patients was 9.0 months, and the six-month PFS rate was 72.4%. The median overall survival (OS) was 26 months, and the one-year OS rate was 83.6%. The 18 patients with glioblastoma were analyzed separately from the other patients with HGG, and the median OS was 18 months, and the one-year OS rates were 81.8%. The median PFS was seven months, and the six-month PFS rate was 75.0%. Conclusion : Our results are consistent with many other reports, confirming that CCRT with TMZ achieves good clinical outcomes in the treatment of HGG. Therefore, we suggest that CCRT with TMZ as adjuvant chemotherapy be considered as a standard therapy for patients with HGG.

• Journal of Chest Surgery
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• v.51 no.3
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• pp.195-201
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• 2018

Background: We investigated the surgical outcomes of patients who underwent therapeutic surgery for malignant pleural mesothelioma (MPM) at a single center. Methods: A retrospective review of 21 patients who underwent therapeutic surgery for MPM from January 2001 to June 2015 was conducted to assess their outcomes. The patients' characteristics and postoperative course, including complications, mortality, overall survival, and recurrence-free survival, were analyzed. Results: Of the 21 patients who underwent therapeutic surgery, 1 5 (71.4%) underwent extrapleural pneumonectomy, 2 pleurectomy (9.5%), and 4 excision (1 9.1 %). The median age was 57 years (range, 32-79 years) and 15 were men (71.4%). The mean hospital stay was 1 6 days (range, 1-63 days). Median survival was 14.3 months. The survival rate was 54.2%, 35.6%, and 21.3% at 1, 3, and 5 years, respectively. In patients' postoperative course, heart failure was a major complication, occurring in 3 patients (14.3%). The in-hospital mortality rate was 2 of 21 (9.5%) due to a case of severe pneumonia and a case of acute heart failure. Conclusion: A fair 5-year survival rate of 21.3% was observed after surgical treatment. Heart failure was a major complication in our cohort. Various surgical methods can be utilized with MPM, each with its own benefits, taking into consideration the severity of the disease and the comorbidities of the patient. Patients with local recurrence may be candidates for surgical intervention, with possible satisfying results.

• Korea journal of population studies
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• v.6 no.1
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• pp.43-69
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• 1983

This study was conducted to make the life tables from specific causes of death in Korea. Both "Life tables of Korea in l978-79" and "the statistics on causes of death statistics in 1980" issued by Economic Planning Board were used as source of data for this study. Among the 58, 187 death certificates reported to the concerned authorities, 39, 801 causes were drawn for the purpose of this study. As a result, it is revealed that two thirds of men in Korea died from these 10 major causes of death. The summarized results are as follows: 1. According to recent statistics, 10 major causes of death in 1980 were shown in the order of 1) malignant neoplasms, 2) cerebrovascular disease, 3) accidents and adverse effects, 4)hypertensive disease, 5) ischaemic heart disease and heart attack, 6) chronic liver disease and cirrhosis, 7) tuberculosis, 8) pneumonia, bronchitis, emphysema and asthma, 9) suicide, 10) diabetes mellitis. 2. The major causes of death in Korea were very similar to those of developed countries such as West Germany, Denmark and Japan. This means that our pattern of death causes is almost approaching to that of developed countries. 3. Our crude death rate in 1980 was on the line of 6.6 per 1, 000 people. This is very low level, compared with 12.1 in West Germany and 10.0 in Denmark, however, our age sepcific death rate was on the verge of doubled level in each age category as to that of West Germany, Denmark and Japan. The fact tells us that our death rate is very high yet, especially in young and prime adult age, and the proportion of the aged is quite low. 4. Average ages of people died from malignant neoplasms, cerebro vascular diseases and hypertensive diseases were 63.1, 66.6, 67.3 respectively, however, that of accidents and adverse effect was only 42.5. This shows that accidents occur indifferently from age. 5. In the curve of eventual death probability, the curve of malignant neoplasms was the highest of all curves before 60 in age. However, the probability curve of eventually dying from accidents and adverse effects tends to decline with age. 6. In this study five life tables from major causes of death (four leading causes of death and of tuberculosis) were constructed for 1979. These life tables are reflecting accurately the effects of age distribution on the specific cause of death. In the surviving curje of these tables we can see that the curve of accidents is adversely related to age. While curves of neoplasms, hypertension and tuberculosis are not diminishing before 40 in age, they are going sharply downward after 50 in age.ard after 50 in age.