• Radiation Oncology Journal
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• v.20 no.1
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• pp.17-23
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• 2002

Purpose : To clarify the clinical benefit derived from the combined modality therapy (CMT) consisting of chemotherapy (CT) and involved field radiotherapy (RT) for stage I and II angiocentric lymphomas of the head and neck. Materials and Methods : Of 143 patients with angiocentric lymphoma of the head and neck treated at our hospital between 1976 and 1995, 104 patients (RT group) received involved field RT alone with a median dose of 50.4 Gy (range : 20~70 Gy), while 39 patients (CMT group) received a median 3 cycles (range : 1~6 cycles) of CT before involved field RT. The response rate, patterns of failure, complications, and survival data of the RT group were compared with those of the CMT group. Results : Despite a higher response rate, local failure was the most common pattern of failure in patients of both groups. The patterns of failure, including the systemic relapse rate were not influenced by the addition of combination CT. Although both modalities were well tolerated by the majority of patients, aberrant immunologic disorders or medical illnesses, such as a hemophagocytic syndrome, sepsis, intractable hemorrhage, or the evolution of second primary malignancies were more frequently observed in patients of the CMT group. The prognosis of patients in the RT group was relatively poor, with a 5-year overall actuarial survival rate of 38% and disease-free survival rate of 32%, respectively. However, their clinical outcome was not altered by the addition of systemic CT. Achieving complete remission was the most important prognostic factor by univariate and multivariate analyses, but treatment modality was not found to be a prognostic variable influencing survival. Conclusions : Involved field RT alone for angiocentric lymphoma of the head and neck was insufficient to achieve an improved survival rate, but the addition of CT to involved field RT failed to demonstrate any therapeutic advantage over involved field RT alone.

• Radiation Oncology Journal
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• v.15 no.4
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• pp.357-367
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• 1997

Purpose : To identify variable prognostic factors and analyse failure patterns in the uterine cervix cancer after radical operation and adjuvant radio-therapy, a retrospective analysis was undertaken. Materals and Methods : I analysed one hundred and twenty four patients with uterine cervix cancer, FIGO stage IB, IIA and IIB, treated with radical hysterectomy and pelvic lymph node dissection followed by adjuvant radio-therapy between May 1985 and May 1994. Minimum follow up period was 24 months. All of them were treated with full dose external radiotherapy with linear accelerator and/or high dese rate intracavitary radiation. Results : Overall 5 year survival rate and relapse free survival rate were $75.4\%,\;73.5\%$, respectively. Significant prognostic factors by relapse free survival were wall involvement thickness, lymph node location and number, parametrium involvement, tumor size, stage, uterine body involvement, vaginal resection margin involvement. By multivariate analysis, lymph node matastasis. tumor size and vaginal resection margin involvement were significant prognostic factos. Treatment related failure were 33 cases. Locoregional failure were more likely in the stage IIB, lymph node positive or vaginal resection margin positive patients whereas distant failures were relatively more frequent in stage IB, IIA and lymph node, vaginal resection negative patients. In stage IIB, 5 year relapse free survival rate was only $56\%$ and nine of twenty two patients recurred. Conculsion : Postoperative radiotherapy results are good for patients with relatively low risk factor. But the results are poor for patients with multiple, high risk factors or stage IIB. To control recurrence for patients with high risk factors, postoperative adjuvant radiotherapy is not sufficient treatment method. To raise control rate adding other methods such as radiosensitizing agent or chemotherapy is necessary and prospectively randomized study is needed for evaluation of postoperative radiotherapy efficacy and /or other methods. And it is reasonable to treat primary radical radiotherapy for patients with stage IIB cervical cancer instead of radical operation and adjuvant radiotherapy and/or chemotherapy regimen.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.51-61
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• 1998

Purpose : Treatment of choice for uterine cervix cancer stage IIB is radiotherapy. We analyzed survivals, Prognostic factors, patterns of failure and complications. Materials and Methods : This is a retrospective analysis of 167 patients with stage IIB carcinoma of uterine cervix treated with curative external pelvic and high dose rate intracavitary radiotherapy at the Department of Therapeutic Radiology, Soonchunhyang University Hospital from August 1985 to August 1994. All the patients followed up from 3 to 141 months(mean 60 months) and age of patients ranged from 31 to 78 years at presentation(mean : 55 years). Results : Overall complete response rate was $84\%$. The response rate for squamous cell carcimoma and adenocarcinoma were $86\%$ and $60\%$, respectively. Overall 5-years survival rate and disease free survival rate was 62 and $59\%$, respectively Mass size and treatment response were significant Prognostic factors for survival Pathologic type and parametrial involvement were marginally significants Prognostic factors. Local failure was 43 cases, distant metastasis was 14 cases and local failure plus distant metastasis was 3 cases, and most of local failures occurred within 24 months, distant metastasis within 12 months after treatment Twenty eight($16.8\%$) patients developed late rectal and urinary complications There were tendency to increasing severity and frequency according to increased fractional dose and total(rectal and bladder) dose. Conclusions : Survival rate was significantly related to tumor size and radiotherapy response. Tumor size should be considered in the clinical s1aging. To increased survival and local control, clinical trials such as decreasing duration of radiotherapy or addition of chemotherapy is needed. To detect early recurrence, regular follow up after RT is important. Because total rectal and bladder dose affected late complications. meticulous vaginal packing is needed to optimize dose of normal tissues and to decrease late complications.

• Tuberculosis and Respiratory Diseases
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• v.50 no.4
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• pp.473-483
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• 2001

Background : There are only a few studies regarding the causes of treatment failure for tuberculosis. Therefore, this study aimed to determine the causes of intractable tuberculosis. Methods : M. tuberculosis, differentiated MOTT (Mycobacterium Other Than Tuberculosis) were isolated, and the RFLP (Restriction fragments length polymorphisms) pattern was analyzed from 204 patients with pulmonary tuberculosis and 53 suffering from neck tuberculosis. The IL-$1{\beta}$, IL-12, $^*1\;IFN{\gamma}$ and $^*2\;TNF{\alpha}$ blood levels were measured. All patients were regularly followed for 18 months after treatment. Results : There was no correlation between the RFLP patterns of M. tuberculosis treatment failure. From the 204 cases, 31.9% were intractable. The characteristics of patients with intractable tuberculosis were old age, being male and recurrent cases. The causes of treatment failure were identified as follows ; a decrease in the IL-12(59.4%) concentration, drug resistant strain(54.7%), irregular medication(15.4%), MOTT(6.2%) and a heavy infection(4.6%). The causes of all cases of intractable tuberculosis could be investigated. The IL-12 concentration in the blood was significantly lower in the intractable cases, where it disclosed a maximum sensitivity(64.7%) and specificity(75.4%) at 165.0 pg/mL. Most of the 53 cases of neck node tuberculosis were treated successfully. Therefore, we were unable to analyze the cause of treatment failure. Conclusion : A decrease in the blood IL-12 concentration and drug resistant strains were identified as the most significant causes of treatment failure for tuberculosis. In Korea, infection by clusters were prevalent, but no difference in the clinical course between clusters and non-clusters could be found.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.224-229
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• 2001

Purpose : The aim of this study is to analyze the treatment failure patterns and the risk factors for locoregional or distant failure of uterine cervical carcinoma treated with radiation therapy. Materials and methods . A retrospective analysis was undertaken of 154 patients treated with curative radiation therapy in Gyeongsang National University Hospital from April 1989 through December 1997. According to FIGO classification, 12 patients were stage IB, 24 were IIA, 98 were IIB, 1 were IIIA, 17 were IIIB, 2 were IVA. Results : Overall treatment failure rate was $42.1\%$ (65/154), and that of complete responder was $31.5\%$ (41/130). Among 65 failures, 25 failed locoregionally, another 25 failed distantly, and 15 failed locoregionally and distantly. Multivariate analysis confirmed tumor size (>4 cm) as risk factor for locoregional failure, and tumor size (>4 cm), pelvic lymph node involvement as risk factors for distant failure. Conclusion : On the basis of results of our study and recent published data of prospective randomized study for locally advanced uterine cervical carcinoma, we concluded that uterine cervical carcinoma with size more than 4 cm or pelvic lymph node involvement should be treated with concurrent chemoradiation.

• Journal of Chest Surgery
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• v.46 no.6
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• pp.449-456
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• 2013

Background: Tumor recurrence is the most common cause of treatment failure, even after complete resection of early-stage non-small cell lung cancer (NSCLC). In this study, we investigated the prognosis of patients with early recurrence in order to identify independent risk factors related to early recurrence. Methods: Between February 1995 and December 2012, 242 patients who underwent surgical resection for stage I NSCLC at Dong-A University Hospital were reviewed. The factors predicting overall survival (OS) and early recurrence were investigated. We also investigated the relationship between the patterns and period of recurrence and clinicopathological factors. Results: For patients with stage IA and IB NSCLC, the 5-year OS rate was 75.7% and 57.3% (p=0.006), respectively. A multivariate Cox proportional hazards model demonstrated that gender (p=0.004), comorbidity number (p=0.038), resection type (p=0.002), and tumor size (p=0.022) were the statistically significant predictors of OS. Moreover, the multivariate analysis revealed that smoking history (p=0.023) and histologic grade (p=0.012) were the independent predictors of early recurrence. Additionally, only histologic grade (poor differentiation) was found to be significantly associated with a higher frequency of distant metastasis; there was no relationship between the patterns and period of recurrence and clinicopathological factors. Conclusion: The present study demonstrated that smoking history and histologic grade were independent prognostic factors for early recurrence within two years in patients with early-stage NSCLC. Patients with these predictive factors may be good candidates for adjuvant therapy.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.87-92
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• 2000

In excavation of tunnels especially located in shallow depth, it is not rare to meet geological change in excavation progress worse than expected in the initial design stage. This paper present a case study on the re-design of excavation and support system of a shallow tunnel under construction where it meets the unexpected bad geological condition during excavation. The detailed geological investigation shows that the rock mass is heavily weathered and fractured with RMR value less than 20. Considering this geological condition, the design concept is focused on the reinforcement of the ground preceding the excavation of tunnel. Two design patterns, LW-grouting & forepoling with pilot tunnelling method and the steel pipe reinforced grouting method, are suggested. Numerical analysis by FLAC shows that these two patterns give the tunnel and roof ground stable in excavation process while the original design causes severe failure zone around the tunnel and floor heaving. In point of the mechanical stability and the degree of construction, the steel pipe reinforced grouting technique proved to be good for the reinforcement of heavily fractured rock mass in tunnelling. This assessment and design process would be a guide in the construction of tunnels in heavily weathered and fractured rock mass situation.

• Journal of Broadcast Engineering
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• v.9 no.1
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• pp.43-53
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• 2004

In this paper, we propose a robust deinterlacing algorithm which combines edge dependent interpolation (EDI) and global motion compensation (GMC). Generally, EDI algorithm shows a visually better performance than any other deinterlacing algorithm using one field. However, due to the restriction of information in one field, a high duality progressive image from Interlaced sources cannot be acquired by intrafield methods. On the contrary, since algorithms based on motion compensation make use of not only spatial information but also temporal information, they yield better results than those of using one field. However, performance of algorithms based on motion compensation depends on the performance of motion estimation. Hence, the proposed algorithm makes use of mixing process of EDI and GMC. In order to obtain the best result, an adaptive thresholding algorithm for detecting the failure of GMC is proposed. Experimental results indicate that the proposed algorithm outperforms the conventional approaches with respect to both objective and subjective criteria.

• Journal of Korean Neurosurgical Society
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• v.42 no.4
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• pp.286-292
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• 2007

Objective : Gamma Knife Stereotactic Radiosurgery (GK SRS) has become an important treatment modality for vestibular schwannomas. We evaluated the tumor control rate, patterns of tumor volume change and preservation of hearing following low-dose radiation for vestibular schwannomas in a homogeneous cohort group in which the mean marginal dose was 12 Gy. Methods : A total of 59 patients were enrolled in this study. All enrolled patients were followed-up for at least 5 years and the radiation dose was 11-13 Gy. Regular MRI, audiometry and clinical evaluations were done and tumor volumes were obtained from MRI using the OSIRIS program. Results : The tumor control rate was 97%. We were able to classify the patterns of change in tumor volume into three categories. Transient increases in tumor volume were detected in 29% of the patients and the maximum transient increase in tumor volume was identified at 6 to 30 months after GK SRS. The transient increases in tumor volume ranged from 121% to 188%. Hearing was preserved in 4 of the 12 patients who had serviceable hearing prior to treatment. There were no other complications associated with GK SRS. Conclusion : Low-dose GK SRS was an effective and safe mode of treatment for vestibular schwannomas in comparison to the previously used high-dose GK SRS. Transient increases in tumor volume can be identified during the follow-up period after low-dose GK SRS for vestibular schwannomas. Physicians should be aware that these increases are not always indicative of treatment failure and that close observation is required following treatments. Unfortunately, a satisfactory hearing preservation rate was not achieved by reducing the radiation dose. It is thought that hearing preservation is a more sophisticated problem and further research is required.

• Steel and Composite Structures
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• v.36 no.3
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• pp.261-272
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• 2020

A novel precast concrete-encased steel composite beam, which can be abbreviated as PCES beam, is introduced in this paper. In order to investigate the shear behavior of this PCES beam, a test of eight full-scale PCES beam specimens was carried out, in which the specimens were subjected to positive bending moment or negative bending moment, respectively. The factors which affected the shear behavior, such as the shear span-to-depth aspect ratio and the existence of concrete flange, were taken into account. During the test, the load-deflection curves of the test specimens were recorded, while the crack propagation patterns together with the failure patterns were observed as well. From the test results, it could be concluded that the tested PCES beams could all exhibit ductile shear behavior, and the innovative shear connectors between the precast concrete and cast-in-place concrete, namely the precast concrete transverse diaphragms, were verified to be effective. Then, based on the shear deformation compatibility, a theoretical model for predicting the shear capacity of the proposed PCES beams was put forward and verified to be valid with the good agreement of the shear capacities calculated using the proposed method and those from the experiments. Finally, in order to facilitate the preliminary design in practical applications, a simplified calculation method for predicting the shear capacity of the proposed PCES beams was also put forward and validated using available test results.