• Radiation Oncology Journal
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• v.16 no.4
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• pp.469-475
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• 1998

Purpose : To determine the role of Pelvic irradiation in stage I or IIA cervical carcinoma with pelvic nodal metastasis after hysterectomy and bilateral pelvic lymphadenectomy. Materials and Methods : This is a retrospective study of 68 cervical carcinoma patients who were found to have pelvic nodal metastasis at hysterectomy and received pelvic irradiation from 1983 to 1996 at Inje University Seoul Paik Hospital. External beam radiation therapy to pelvis was delivered using 4 MeV Linac and intracavitary irradiation was given via vaginal ovoids or cylinders. Five-year survival and disease-free survival were estimated by Kaplan-Meier Method and prognostic factors related to survival were analysed by log-rank test and Cox proportional hazards regression model. Results : Median length of follow-up was 52months. Five-year overall survival and disease-free survival (DFS) were 81.8$\%$ and 81.7$\%$ respectively. Patients with endometrial invasion had a 57.1$\%$ 5-year DFS compared to 87.5$\%$ for those without endometrial invasion (p=0.0074). Multivariate analysis revealed endometrial invasion as an only statistically significant prognostic factor for 5-year DFS. Among total 15 (22$\%$) recurrences. pelvic recurrences occurred in 4 cases and distant metastases occurred in 13 cases. Conclusion : We have been able to confirm previous results demonstrating marked decrease in local recurrence after pelvic irradiation. In view of the high proportion of distant metastasis found in this study, a trial of aggressive adjuvant systemic therapy and irradiation in early stage cervical carcinoma patients with pelvic nodal metastasis, especially with endometrial invasion, appears to be warranted.

• Radiation Oncology Journal
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• v.19 no.4
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• pp.327-334
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• 2001

Purpose : To find out the role of postoperative adjuvant radiotherapy in the treatment of rectal cancer by comparing survival, pelvic control, complication rate, and any prognostic factor between surgery alone and postoperative radiotherapy group. Materials and methods : From Feb. 1982 to Dec. 1996 total 212 patients were treated by radical surgery with or without postoperative radiotherapy due to rectal carcinoma of modified Astler-Coiler stage $B2\~C3$. Of them, 18 patients had incomplete radiotherapy and so the remaining 194 patients were the database analyzed in this study. One hundred four patients received postoperative radiotherapy and the other 90 patients had surgery only. Radiotherapy was peformed in the range of $39.6\~55.8\;Gy$ (mean: 49.9 Gy) to the whole pelvis and if necessary, tumor bed was boosted by $5.4\~10\;Gy$. Both survival and pelvic control rates were calculated by Kaplan-Meier method and their statistical significance was tested by Log-rank test. Multivariate analysis was peformed by Cox proportional hazards model. Results : 5-year actuarial survival rate (5YSR) and 5-year disease-free survival rate (5YDFSR) of entire patients were $53\%\;and\;49\%$, respectively. 5YSRs of surgery alone group and adjuvant radiotherapy group were $63\%\;vs\;45\%$, respectively (p=0.03). This difference is thought to reflect uneven distribution of stages between two treatment groups (p<0.05 by $\chi^2-test$) with more advanced disease patients in adjuvant radiotherapy group. 5YSRs of surgery alone vs adjuvant radiotherapy group in MAC B2+3, C1, C2+3 were $68\%\;vs\;55\%$ (p=0.09), $100\%\;vs\;100\%$, $40\%\;vs\;33\%$ (p=0.71), respectively. 5YDFSRs of surgery alone vs adjuvant radiotherapy group in above three stages were $65\%\;vs\;49\%$ (p=0.14), $100\%\;vs\;100\%$, $33\%\;vs\;31\%$ (p=0.46), respectively. 5-year pelvic control rate (5YPCR) of entire patients was $72.5\%$. 5YPCRs of surgery alone and adjuvant radiotherapy group were $71\%\;vs\;74\%$, respectively (p=0.41). 5YPCRs of surgery alone vs adjuvant radiotherapy group in B2+3, C1, C2+3 were $79\%\;vs\;75\%$ (p=0.88), $100\%\;vs\;100\%$, $44\%\;vs\;68\%$ (p=0.01), respectively. Multivariate analysis showed that only stage was significant factor affecting overall and disease-free survival in entire patients and also in both treatment groups. In view of pelvic control, stage and operation type were significant in entire patients and only stage in surgery alone group but in adjuvant radiotherapy group, operation type instead of stage was the only significant factor in multivariate analysis as a negative prognostic factor in abdominoperineal resection cases. Conclusion : Our retrospective study showed that postoperative adjuvant radiotherapy could improve the pelvic control in MAC C2+3 group. To improve both pelvic control and survival in all patients with MAC B2 or more, other treatment modality such as concurrent continuous infusion of 5-FU, which is the most standard agent, with radiotherapy should be considered.

• Journal of Korean Neurosurgical Society
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• v.30 no.11
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• pp.1263-1270
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• 2001

Objective : To analyze the radiosurgical results of intracranial meningiomas after Gamma Knife radiosurgery (GKS) and to assess the possible factors related to the outcome and complications in treating meningiomas. Patients and Methods : We retrospectively reviewed the clinical and radiological data in 179 patients(194 lesions) treated with GKS for intracranial meningiomas between May 1992 and October 2000. Radiosurgical responses were categorized as shrinkage, stasis and enlargement, and we defined the shrunken and static group as a radio-logical control. A Cox proportional hazards model was used to evaluate the correlation between the radiosurgical outcomes and various factors such as location and size of tumor, age and gender of patients, relation to venous sinus, pre-GKS degree of edema, treatment modality, radiosurgical parameters, and pathologic findings. Results : Patients were grouped into skull base meningiomas(57.7%), non-skull base tumor including convexity, parasagittal, and falx meningiomas(37.1%), and others(5.2%) according to the location of tumors. The mean maximum dose and the margin dose of tumor was 30.0Gy(19-45Gy) and 15.1Gy(9.5-24.5Gy), respectively. The mean volume of the tumors was 9.4cc(0.003-45.0cc). The radiologic control rate was 97.1%. The radiation induced imaging change with or without neurologic deficit was the most common complication(23.6%). There were seen mostly in convexity, parasagittal, and falx meningiomas which were deeply embedded in cortex. Conclusion : GKS for intracranial meningioma seems to be safe and effective treatments. However, GKS should be considered very cautiously in non-skull base tumor such as convexity, parasagittal, or falx meningiomas with regards to patient's age and general condition, size and location of tumor, pattern of embedding into cortex, presenting symptoms and patient's preference.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6523-6528
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• 2013

Background: Cigarette smoking is the largest single recognized cause of human cancers. In Western countries, many epidemiologists have reported risk factors for kidney cancer including smoking. However, little is known about the Japanese population. Materials and Methods: We evaluated the association of smoking with the risk of kidney cancer death in the Japan Collaborative Cohort (JACC) Study. Participants included 46,395 males and 64,190 females. The Cox proportional hazards model was used to determine age-and-sex adjusted relative risks. Results: A total of 62 males and 26 females died from kidney cancer during the follow-up of 707,136 and 1,025,703 person-years, respectively. Heavy smokers (Brinkman index >1200), fondness of fatty foods, hypertension, diabetes mellitus (DM), and obesity were suggested to increase the risk of renal cell carcinoma while walking was suggested to decrease the risk. Even after controlling for age, sex, alcohol drinking and DM, heavy smoking significantly increased the risk. Conclusions: The present study suggests that six factors including smoking may increase and/or reduce the risk of kidney cancer in the Japanese population. Because of the small number of outcomes, however, we did not evaluate these factors after adjusting for all possible confounding factors. Further studies may be needed to confirm the findings in this study.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.3
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• pp.971-977
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• 2015

Malignant glioblastoma multiforme (GBM) is the most malignant brain tumor and despite recent advances in diagnostics and treatment prognosis remains poor. In this retrospective study, we assessed the clinical and radiological parameters, as well as fluorescence in situ hybridization (FISH) of 1p19q deletion, in a series of cases. A total of 816 patients with GBM who received surgery and radiation between January 2010 and May 2014 were included in this study. Kaplan-Meier survival analysis and Cox regression analysis were used to find the factors independently influencing patient progression free survival (PFS) and overall survival (OS). Age at diagnosis, preoperative Karnofsky Performance Scale (KPS) score, KPS score change at 2 weeks after operation, neurological deficit symptoms, tumor resection extent, maximal tumor diameter, involvement of eloquent cortex or deep structure, involvement of brain lobe, Ki-67 and MMP9 expression level and adjuvant chemotherapy were statistically significant factors (p<0.05) for both PFS and OS in the univariate analysis. Cox proportional hazards modeling revealed that age ${\leq}50$ years, preoperative KPS score ${\geq}80$, KPS score change after operation ${\geq}0$, involvement of single frontal lobe, deep structure involvement, low Ki-67 and MMP9 expression and adjuvant chemotherapy were independent favorable factors (p<0.05) for patient clinical outcomes.

• Journal of Korean Neurosurgical Society
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• v.54 no.5
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• pp.399-404
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• 2013

Objective : The authors conducted a retrospective cohort study to determine prognostic factors and treatment outcomes of brain metastases (BM) from breast cancer (BC) after Gamma Knife radiosurgery (GKS). Methods : Pathologic and clinical features, and outcomes were analyzed in a cohort of 62 patients with BM from BC treated by GKS. The Kaplan- Meier method, the log-rank test, and Cox's proportional hazards model were used to assess prognostic factors. Results : Median survival after GKS was 73.0 weeks (95% confidence interval, 46.0-100.1). HER2+ [hazard ratio (HR) 0.441; p=0.045], Karnofsky performance scale (KPS) ${\geq}70$ (RR 0.416; p=0.050) and systemic chemotherapy after GKS (RR 0.282; p=0.001) were found to be a favorable prognostic factor of overall survival. Actuarial local control (LC) rate were $89.5{\pm}4.5%$ and $70.5{\pm}6.9%$ at 6 and 12 months after GKS, respectively. No prognostic factors were found to affect LC rate. Uni- and multivariate analysis revealed that the distant control (DC) rate was higher in patients with; a small number (${\leq}3$) of metastasis (HR 0.300; p=0.045), no known extracranial metastasis (p=0.013, log-rank test), or the HER2+ subtype (HR 0.267; p=0.027). Additional whole brain radiation therapy and metastasis volume were not found to be significantly associated with LC, DC, or overall survival. Conclusion : The treatment outcomes of patients with newly diagnosed BM from BC treated with GKS could be affected primarily by intrinsic subtype, KPS, and systemic chemotherapy. Therapeutic strategy and prognosis scoring system should be individualized based on considerations of intrinsic subtype in addition to traditionally known parameters related to stereotactic radiosurgery.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.4
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• pp.195-200
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• 2020

With the growing interest in fossil fuel depletion and environmental pollution, railroad cars operating in Korea are in progress as the conversion from diesel to electric vehicles expands. The photovoltaic system, which is applied as an example of the conversion of electric vehicles, is infinite and pollution-free, and can produce energy without generating hazards such as air pollution, noise, heat, and vibration, and maintain fuel transportation and power generation facilities. There is an advantage that is rarely needed. However, the amount of electricity produced depends on the amount of solar radiation by region, and the energy density is low due to the power generation of about 25㎡/ kWp, so a large installation area is required and the installation place has limited problems. In view of these problems, many studies have been applied to fuel cells in the railway field. In particular, the plan to link the fuel cell power generation system railroad power supply system must be linked to the power supply system that supplies power to the railroad, unlike solar and wind power. Therefore, it has a close relationship with railroad cars and the linkage method can vary greatly depending on the system topology. Therefore, in this paper, we study the validity through simulation modeling related to linkage analysis according to system topology.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.221-227
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• 2001

Objective : The therapeutic impact of tumor resection in glioblastomas is poorly defined and still questionable. Therefore, we conducted the current study to verify the role of tumor resection in the treatment of these highly malignant tumors. Methods : A retrospective study was performed(1990-1999) to compare the treatment results of surgical resection plus radiotherapy(130 patients) with those of stereotactic biopsy plus radiotherapy(19 patients) in glioblastomas. Only adult patients with supratentorial, de novo glioblastoma located in one lobe were included. Survival time/rate was analysed with Kaplan-Meier method, and prognostic variables were obtained from the univariate log-rank test and the multivariate Cox's proportional hazards model. Results : The resection group and the biopsy group did not differ in terms of age, gender, duration of symptoms, presenting symptoms, tumor location, tumor side, tumor size, and the frequency of midline shift. Patients in the biopsy group more often were found to have worse preoperative Karnofsky performance status(KPS)(p=0.001). On univariate analysis, age, KPS, and tumor side were associated with survival(p=0.0053, 0.0001, and 0.0331 respectively). Median survival time and 1-year survival rate were also statistically improved by tumor resection ; resection group - 13 months and 61.2%, and biopsy group - 8 months and 19.7%, respectively(p=0.0001). In patients with midline shift of the tumor, resection was highly effective comparing to biopsy(p=0.0001), but in patients without midline shift, external beam radiation alone was as effective as tumor resection(p=0.0605). Other prognostic variables did not affect survival. On multivariate analysis after variable selection, survival was independently associated with KPS(p=0.001), but not the surgical resection(p=0.2837). Even in biopsy group with midline shift of the tumor, survival rate was not different from that seen after tumor resection(p=0.3505). Conclusions : Radiotherapy alone was as effective as tumor resection plus radiotherapy in patients without midline shift of the tumor. Although there was not statistically significant, tumor resection looked like effective in patients with midline shift. For supratentorial, lobar glioblastoma patients without mass effect of the tumor, biopsy with radiotherapy is one of rational treatment strategies. We consider that tumor resection should be performed in patients with pretreatment midline shift.

• Journal of Chest Surgery
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• v.36 no.7
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• pp.489-496
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• 2003

To clarify the prognostic implication of the location and number of the metastatic mediastinal nodes in resected stage IIIA N2 non-small cell lung cancer. Material and Method: One hundred and seventy-four patients with resected non-small cell lung cancer who eventually proved to have pathologic stage IIIA N2 disease were studied. Patients who received preoperative induction therapy, non-curative operation or defined as operative mortality were excluded from this study. Result: In upper lobe tumors, there was no difference in 5-year survival according to the involvement of lower mediastinal nodes (32.3% vs 25.6%, p＝0.86). In lower lobe tumors, no difference was found in 5-year survival according to the involvement of upper mediastinal nodes (25.1% vs 14.1%, p＝0.33). There was no significant difference in 5-year survival between patients with or without metastatic subcarinal node (20.9% vs 25.6%, p＝0.364). In terms of the number of metastatic mediastinal nodes, 5-year survival was better in single station group (26.3%) than multiple station group (18.3%) (p＝0.048). In multiple station N2 group, the patients who received postoperative chemotherapy and radiation therapy had better 5-year survival (34.2%) (p＝0.01). Cox's proportional hazards model revealed that the age $\geq$60 (O.R: 1.682, p＝.006), multiple station N2 (O.R: 1.503. p＝0.021), pneumonectomy (O.R: 1.562, p＝0.018), postoperative chemotherapy and radiation therapy (O.R: 0.625, p＝0.012) were the factors affecting the postoperative survival. Conclusion: Multiple station N2 disease was the important prognostic factor for postoperative survival in resected stage IIIA N2 non-small cell lung cancer. Postoperative chemotherapy and radiotherapy were thought to improve the survival in case of multiple station N2 disease.

• Journal of Gastric Cancer
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• v.5 no.4 s.20
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• pp.281-287
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• 2005

Purpose: This study was conducted to evaluate the effectiveness and the role of post-operative adjuvant chemoradiation therapy in a stage-II (UICC, 1997) primary gastric cancer. Materials and Methods: From September 1994 to December 2004, 954 stage-II gastric-cancer patients were seen, and all of them underwent a curative resection with extensive (D2) lymph-node dissection. The chemotherapy consisted of fluorouracil $(400mg/m^2)$ plus leucovorin $(20mg/m^2)$ for 5 days, followed by 4,500 cGy of radiotherapy for 5 weeks with fluorourcil and leucovorin on the first 4 days and the last 3 days of radiotherapy. Two five-day cycles of chemotherapy were given four weeks after the completion of radiotherapy. The Kaplan-Meier method was used to estimate the survival rates. To assess the importance of potential prognostic factors, we performed univariate and multivariate analyses using a log-rank test and Cox's proportional hazards regression model. A P value <0.05 was considered significant. Results: Univariate analysis revealed that age, tumor size, gross type, surgical method, and postoperative adjuvant therapy had statistical significance. Among these factors, age, surgical method, tumor size, surgical method, and postoperative adjuvant therapy were found to be independent prognostic factors by using a multivariate analysis. The postoperative adjuvant chemotherapy group and the chemoradiation therapy group had survival benefit compared to the surgery-only group. However the chemoradiation therapy group had no significant survival benefit compared to the chemotherapy group. Conclusion: The postoperative adjuvant therapy in stage-II gastric-cancer patients had significant benefit. Therefore, postoperative adjuvant chemoradiation therapy has an acceptable effect. A large-scale, randomized study is needed to evaluate the effectiveness and the role of postoperative radiation therapy.