• Journal of the Korean Data and Information Science Society
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• v.8 no.2
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• pp.119-125
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• 1997

We handle the stochastic processes of independent and identically distributed random variables. But random variables are usually dependent among themselves in actual life. So in this paper, we find out a new process not satisfying Markov property. We investigate the probability mass functions and study on the probability of the first-passage time. Also we find out the average frequency of continuous successes in from 0 to n time.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1545-1549
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• 2014

Background: Published studies on clinical outcome of helical tomotherapy for lung cancer are limited. The purpose of this study was to evaluate clinical outcomes and treatment-related toxicity in inoperable non-small cell lung cancer (NSCLC) patients treated with helical tomotherapy in Korea. Materials and Methods: Twenty-seven patients with NSCLC were included in this retrospective study. Radiotherapy was performed using helical tomotherapy with a daily dose of 2.1-3 Gy delivered at 5 fractions per week resulting in a total dose of 62.5-69.3 Gy. We assessed radiation-related lung and esophageal toxicity, and analyzed overall survival, locoregional recurrence-free survival, distant metastasis-free survival, and prognostic factors for overall survival. Results: The median follow-up period was 28.9 months (range, 10.1-69.4). The median overall survival time was 28.9 months, and 1-, 2-, and 3-year overall survival rates were 96.2%, 92.0%, and 60.0%. The median locoregional recurrence-free survival time was 24.3 months, and 1-, 2-, and 3-year locoregional recurrence-free survival rates were 85.2%, 64.5%, and 50.3%. The median distant metastasis-free survival time was 26.7 months, and 1-, 2-, and 3-year distant metastasis-free survival rates were 92.3%, 83.9%, and 65.3%, respectively. Gross tumor volume was the most significant prognostic factor for overall survival. No grade 4 or more toxicity was observed. Conclusions: Helical tomotherapy in patients with inoperable NSCLC resulted in high survival rates with an acceptable level of toxicity, suggesting it is an effective treatment option in patients with medically inoperable NSCLC.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1803-1806
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• 2014

Endoscopic submucosal dissection (ESD) was originally developed for en bloc resection of large, flat gastrointestinal lesions. Compared with endoscopic mucosal resection (EMR), ESD is considered to be more time consuming and have more complications for treatment of early esophageal carcinoma, such as bleeding, stenosis and perforation. The objective of this study was to compare the efficacy and safety of ESD and EMR for such lesions. We searched databases, such as PubMed, EMBASE, Cochrane Library and Science Citation Index updated to 2013 for related trials. In the meta-analysis, the main outcome measurements were the en bloc resection rate, the histologically resection rate and the local recurrence rate. We also compared the operation time and the incidences of procedure-related complications. Five trials were identified, and a total of 710 patients and 795 lesions were included. The en bloc and histologically complete resection rates were higher in the ESD group compared with the EMR group (odds ratio (OR) 27.3; 95% CI, 11.5-64.8; OR 18.4; 95% CI, 8.82-38.59). The local recurrence rate was lower in the ESD group (OR 0.13, 95 % CI 0.04-0.43). The meta-analysis also showed ESD was more time consuming, but did not increase the complication rate (P=0.76). The results implied that compared with EMR, ESD showed better en bloc and histologically resection rates, and lower local recurrence, without increasing the incidence of procedure-related complications in the treatment of early esophageal carcinoma.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5951-5956
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• 2015

Background: To evaluate the rate of pathologic high-risk factors, intermediate-risk factors, and treatment outcomes in early-stage cervical cancer patients undergoing radical hysterectomy and pelvic lymphadenectomy (RHPL). Materials and Methods: Medical records of stage IA-IIA1 cervical cancer patients who underwent RHPL during the 2006 to 2012 time period and patient follow-up data until December 2013 were reviewed. Results: Of 331 patients, 52 women (15.7%) had pathologic high-risk factors and 59 women (17.8%) had intermediate-risk factors without high-risk factors. All studied patients had an initial complete response. At median follow-up time of 40.9 months (range 1-103.3 months) and mean follow-up time of$ 43.3{\pm}25.3$ months, 37 women had disease recurrence and 4 women had died of disease. The most common site of recurrence was the pelvis (64.8%). Five-year and 10-year disease free survival rates were 96.1% and 91.5%, respectively. Five-year and 10-year overall survival rates were 100% and 99.4%, respectively. Independent factors related to recurrence were pelvic node metastasis (odds ratio [OR], 2.670; 95%CI, 1.001-7.119), and >1/3 cervical stromal invasion (OR, 3.763; 95%CI, 1.483-9.549). Conclusions: The rates of pathologic high-risk and intermediate-risk factors should be considered and disclosed when counseling patients regarding primary treatment by RHPL. Oncologic outcomes of primary surgical treatment for early-stage cervical carcinoma were found to be excellent.

• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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• pp.54-58
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• 2011

Objectives : There are many reports on attempts to minimize complications and recurrences of tumor by several techniques for benign parotid tumor resection. The purpose of our study is to find out meaning of procedure without identifying main trunk of facial nerve compared to conventional parotidectomy. Material and Methods : We classified 121 patients into two groups. Patients who were underwent superficial parotidectomy or partial superficial parotidectomy were included in idenitification group(IF group), and patients who were treated with conservative partial parotidectomy or extracapsular dissection without identification of main trunk of facial nerve were included in the non-identification group(NF group). We analyzed the location of tumor, operation time, mean drainage duration, complication, recurrence and cosmetic satisfaction in two groups. Results : NF group has shorter operation time and mean drainage duration than IF group, however there is no significant difference in complication and recurrence between two surgical techniques. The Cosmetic satisfaction was similar between two groups. Conclusion : Limited parotidectomy without finding main trunk of facial nerve may be reliable option for benign parotid tumors because it has advantages such as less operation time and mean drainage duration without increasing in recurrence or complication rate.

• Journal of Korean Neurosurgical Society
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• v.65 no.4
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• pp.558-571
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• 2022

Objective : The primary objective of this study was to identify predicting factors for local control (LC) of atypical meningioma, and we validated them with comparing the predicting factors for recurrence-free survival (RFS). We also examined the rate of LC after surgical resection with or without adjuvant treatment and RFS. Methods : Clinical and radiological records of patients with atypical meningiomas diagnosed at two institutes from January 2000 to December 2018 were reviewed retrospectively. Histopathological features were also reviewed using formalin-fixed paraffin embedded samples from pathological archives. Results : Of the 99 atypical meningiomas eligible for analysis, 36 (36.4%) recurred during the follow-up period (mean, 83.3 months; range, 12-232 months). The rate of 3-year LC and 5-year LC was 80.8% and 74.7%, respectively. The mean time-to-recurrence was 49.4 months (range, 12-150). The mean RFS was 149.3 months (95% confidence interval, 128.8-169.8 months) during the mean follow-up duration of 83.3 months (range, 12-232 months). Multivariate analysis using Cox proportional-hazard regression model showed that the extent of resection (hazard ratio [HR], 4.761; p=0.013), Ki67 index (HR, 8.541; p=0.004), mitotic index (HR, 3.275; p=0.044), and tumor size (HR, 3.228; p=0.041) were independently associated with LC. These factors were also statistically associated with RFS. In terms of radiotherapy after surgical resection, the recurrence was not prevented by immediate radiotherapy because of the strong effect of proliferative index on recurrence. Conclusion : The present study suggests that the extent of resection, proliferative index (according to Ki67 expression) and mitotic index, and tumor size are associated with recurrence of atypical meningiomas. However, our results should be further validated through prospective and randomized clinical trials to overcome the inborn bias of retrospective nature of the study design.

• Journal of Gastric Cancer
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• v.9 no.2
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• pp.51-56
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• 2009

Purpose: Peritoneal recurrence has been reported to be the most common form of recurrence of gastric cancer. Peritoneal recurrence can generally be suggested by several types of image studies and also if there is evidence of ascites or Bloomer's rectal shelf. It can be confirmed by explorative laparotomy, but diagnostic laparoscopy is a good alternative method and laparoscopic surgery has also been widely used. We reviewed and analyzed the ability of diagnostic laparoscopy to detect peritoneal recurrence or carcinomatosis, and especially for gastric cancer. Materials and Methods: We performed a retrospective review the 45 gastric cancer patients who were operated via diagnostic laparoscopy between 2004. 2. and 2009. 3. We analyzed the perioperative clinical characteristics and the accuracy of the diagnostic methods. Results: The study groups included 14 patients who had confirmed gastric cancer, but they suspected to have carcinomatosis, and 31 patients who had previously underwent gastric resection, but they suspected to have recurrence. The mean operation time was $44.1\pm26.9$ minutes and the mean postoperative hospital stay was $2.7\pm2.8$ days. There was one case of operation-related complication and no postoperative mortality occurred. The sensitivities for detecting peritoneal recurrence or carcinomatosis were 92.1% for diagnostic laparoscopy, 29.7% for detecting ascites and rectal shelf on the physical examination, 86.5% for abdominal computed tomography, 69.2% for PET CT and 18.8% for CEA. Conclusion: Diagnostic laparoscopy does not require a long operation time or a long hospital stay, and it showed a low complication rate in our study. It has high sensitivity for detecting peritoneal recurrence of gastric cancer. It can be an alternative diagnostic confirmative method and it is useful for deciding on further treatment.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2527-2530
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• 2015

Background: The cancer of the prostate risk assessment (CAPRA) score has been defined to predict prostate cancer recurrence based on the pre-clinical data, then pathological data have also been incorporated. Thus, CAPRA post-surgical (CAPRA-S) score has been developed based on six criteria (prostate specific antigen (PSA) at diagnosis, pathological Gleason score, and information on surgical margin, seminal vesicle invasion, extracapsular extension and lymph node involvement) for the prediction of post-surgical recurrences. In the present study, biochemical recurrence (BCR)-free probabilities after open retropubic radical prostatectomy (RP) were evaluated by the CAPRA-S scoring system and its three-risk level model. Materials and Methods: CAPRA-S scores (0-12) of our 240 radical prostatectomies performed between January 2000-May 2011 were calculated. Patients were distributed into CAPRA-S score groups and also into three-risk groups as low, intermediate and high. BCR-free probabilities were assessed and compared using Kaplan-Meier analysis and Cox proportional hazards regression. Ability of CAPRA-S in BCR detection was evaluated by concordance index (c-index). Results: BCR was present in 41 of total 240 patients (17.1%) and the mean follow-up time was $51.7{\pm}33.0$ months. Mean BCR-free survival time was 98.3 months (95% CI: 92.3-104.2). Of the patients in low, intermediate and high risk groups, 5.4%, 22.0% and 58.8% had BCR, respectively and the difference among the three groups was significant (P = 0.0001). C-indices of CAPRA-S score and three-risk groups for detecting BCR-free probabilities in 5-yr were 0.87 and 0.81, respectively. Conclusions: Both CAPRA-S score and its three-risk level model well predicted BCR after RP with high c-index levels in our center. Therefore, it is a clinically reliable post-operative risk stratifier and disease recurrence predictor for prostate cancer.

• Radiation Oncology Journal
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• v.2 no.1
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• pp.115-122
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• 1984

Total 125 patinets with primary and metastatic Ewing's sarcoma were treated in various ways between 1963 to 1977. Patients were divided into 3 groups according to the treatment methods. Group 1 was nonprotocol patients with or without chemotherapy. Total 58 patients were entered. Group 1 was divided into 2 subgroups. 33 patients were treated locally without chemotherapy and 25 Patients were treated with local therapy and nonprotocol chemotherapy. Group 2 was treated with local therapy and plus T-2 regimen multiagent chemotherapy. 29 patients were entered. Group 3 was treated with local therapy and T-6 regimen multiagent chemotherapy. 38 patients were entered. Local treatments for primary tumor were surgery and/or radiation therapy. Radiation dose ranged between 2,000 and 8,000 rad. Patients with pulmonary metastases received bilateral pulmonary RT. Local recurrence rate was analyzed according to treatment groups and was $16.8\%$. Local 15 yr survival was $33\%$ and 8 yr survival of T-6 group was $64.9\%$. An analysis of time were pattern of recurrence of each group, and the correlation of with radiation dose with local recurrence done. This study concluded that intensive multiagent chemotherapy RT and/or surgery (T-6 regimen) reduced distant metastases, and produced significant increase in local control and survival.

• Journal of Korean Foot and Ankle Society
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• v.15 no.2
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• pp.92-96
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• 2011

Purpose: To compare the result of endoscopic versus open bursectomy in lateral malleolar bursitis, which was not treated conservatively. Materials and Methods: Between January 2008 and October 2009, We divided to two groups, endoscopy (group A) 11 cases, open bursectomy (group B) 11 cases. The average follow up period was 15 months (range, 12 to 18), the mean age was 66 (range, 38 to 79). We compared patients satisfaction, complete healing time, operation time, complications and recurrence. Results: Group A had significant difference in terms of the clinical satisfactions, complete healing time. operation time, complications. Group A showed satisfaction (excellent 9, good 2), mean complete healing time 11.9 (8~14) days, operation time 37 (25~45) minutes, 1 case recur. Group B showed satisfaction (excellent 4, good 3, fair 1, poor 3), complete healing time 32.7 (14~98) days, operation time 22 (18~26) minutes. complication were one case of skin necrosis, one case of wound dehiscence, two cases of superficial peroneal nerve injury, no recurrence. Significant advantages of endoscopic method include lower morbidity and rapid wound healing period (p<0.05). Conclusion: Endoscopic resection of the lateral malleolar bursitis is a promising technique and shows favourable results compared to the open resection. Significant advantages of this method include lower morbidiy and rapid wound healing.