• Radiation Oncology Journal
• /
• v.18 no.4
• /
• pp.265-276
• /
• 2000

Purpose : Between January 1983 and December 1988, 218 female Patients with known breast cancer and positive axillary nodes were treated with adjuvant radiotherapy and chemotherapy following radical mastectomy. Treatment results were retrospectively analysed at the Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University of College of Medicine. Materials and Methods : The patients were classified into 3 groups; group I included II patients treated with adjuvant chemotherapy alone; in group 2, 52 patients treated with radiotherapy alone; and in group 3, n patients treated with combined chemo-radiotherapy. The mean age was 44 years and ranged from 27 to 70. The median follow-up time was 51 months. Results :Seven-year relapse free and overall survival rates were 56$\%$ and 67$\%$; in group 1, 50$\%$ and 56$\%$ in group 2, 51$\%$ and 65$\%$ and in group 3, 62$\%$ and 75$\%$ respectively. This difference was not statistically significant(p<0.05). The loco-regional failure rates were 13$\%$ and distant failure rates were 33$\%$. There was less risk of loco-regional failure in group 2 and 3 which included radiotherapy (p<0.05). But there was no significantly difference in the rates of distant failure( p>0.05). By univariate analysis, the only significant prognostic factor affecting relapse-free survival was the percentage of positive axillary nodes; and the overall survival significantly correlated with the primary tumor site, the number or percentage of positive axillary nodes, and stage. But in multivariate analysis, the only significant prognostic factor was treatment modality. By univariate analysis of prognostic factors affecting the rates of overall failure and distant failure, the significant prognostic factors was the percentage of positive axillary nodes; and the risk of the loco-regional failure significantly correlated with the treatment modality. Conclusion :In conclusion, these results suggest a potential for decreasing the risk of loco-regional failure with the addition of postoperative radiotherapy to chemotherapy in the premenopausal patients, and in the patients with number or percentage of positive nodes more than 4 or 1/3. The results of this study suggest that the combined chemo-radiotherapy as adjuvant treatment following radical mastectomy was the most effective modaliw in groups of 2$\~$5 cm sized tumor, stage IIB, and in patients with more than 4 or 1/3 of number or percentage of positive nodes.

• Radiation Oncology Journal
• /
• v.15 no.4
• /
• pp.331-337
• /
• 1997

Purpose : To evaluate our experience in the breast-conserving treatment for early breast cancer with special regard to recurrence Pattern and related risk factors. Materials and Method :Two hundred and sixteen patients with AJC stage 1and 11 breast cancer who received breast conserving treatment between January 1991 and December 1994 were evaluated A9e distribution ranged from 23-80 year old with a median a9e of 44. One hundred and seventeen Patients had 71 lesions and 99 Patients had 72 lesions. Axillary lymph nodes were involved in 73 patients. All patients received a breast conserving surgery (wide excision to quadrantectomy) and axillary node dissection followed by radiotherapy. Ninety six patients received chemotherapy before or after radiotherapy. Results : During the follow-up period (3-60 months, median 30 months), local recurrences were noted in six Patients (true: 3, elsewhere; 1, skin: 2). Sixteen patients developed distant metastases as the first sign of recurrence at 8-38 months (median 20 months) after surgery. Among them, three patients simultaneously developed local recurrence with distant metastases. Contralateral breast cancer developed in one Patient and non-mammary cancers developed in three patients. The actuarial 5 year survival rate was $88.4\%\;(stage\;I\;96.7\%,\;stage\;IIa\;95.2\%,\;stage\;IIb\;69.9\%)$. Age, I stage, number of involved axillary lymph nodes. and AJC stage were risk factors for distant metastases in univariate analysis. In the multivariate analysis, the number of involved axillary lymph nodes was the most significant risk factor for metastases. Conclusion : Local recurrence was not common in the early years after radiotherapy. Distant metastases occurred at a steady rate during the first three years and was more common in the Patients with larger tumors, higher number of involved axillary nodes, and younger age.

• Journal of the Korean Geographical Society
• /
• v.51 no.6
• /
• pp.779-797
• /
• 2016

A calibrated hydrological model is a useful tool for quantifying the impacts of the climate variations and land use/land cover changes on sediment load, water quality and runoff. In the rainy season each year, the Xe Bang Fai river basin is provisionally flooded because of typhoons, the frequency and intensity of which are sensitive to ongoing climate change. Severe heavy rainfall has continuously occurred in this basin area, often causing severe floods at downstream of the Xe Bang Fai river basin. The main purpose of this study is to investigate the climate change impact on river discharge using a Soil and Water Assessment Tool (SWAT) model based on future climate change scenarios. In this study, the simulation of hydrological river discharge is used by SWAT model, covering a total area of $10,064km^2$ in the central part of country. The hydrological model (baseline) is calibrated and validated for two periods: 2001-2005 and 2006-2010, respectively. The monthly simulation outcomes during the calibration and validation model are good results with $R^2$ > 0.9 and ENS > 0.9. Because of ongoing climate change, three climate models (IPSL CM5A-MR 2030, GISS E2-R-CC 2030 and GFDL CM3 2030) indicate that the rainfall in this area is likely to increase up to 10% during the summer monsoon season in the near future, year 2030. As a result of these precipitation increases, the SWAT model predicts rainy season (Jul-Aug-Sep) river discharge at the Xebangfai@bridge station will be about $800m^3/s$ larger than the present. This calibrated model is expected to contribute for preventing flood disaster risk and sustainable development of Laos

• Journal of Chest Surgery
• /
• v.32 no.9
• /
• pp.799-805
• /
• 1999

Background: Leakage, stricture formation, and tumor recurrence at the anastomotic site are serious problems after esophagectomy for cancer of the esophagus or cardia. The prevalence of these postoperative complications may be affected by whether an anastomosis is made in the neck or in the chest, therefore a comparison was made between anastomoses made at these two sites. Material and Method: Between 1987 and 1998, 36 patients with cancer of the esophagus underwent transthoracic esophagectomy with cervical(NA, n=20) or thoracic anastomosis(CA, n=16). The tumors were staged postoperatively(stage IIA, n=13; s tage IIB, n=7; stage III, n=16) and were located in the middle thoracic(n=22) or lower thoracic esophagus and cardia(n=14). Result: The overall operative mortality was 8.3%(5% for NA group, 12.5% for CA group). The anastomotic leak rate for the NA group was 15.0% and 12.5% for the CA group. The anastomotic leak rate differed according to the manual(27.3%) or stapled(8.0%) techniques(p < 0.05). The median proximal resection margins in the NA and CA groups were 9.6 cm and 5.8 cm, and the corresponding rates of anastomotic tumor recurrence were 5.3% and 28.6%(p < 0.05). The prevalence of benign stricture formation (defined as moderate/severe dysphagia) was higher in the NA group(36.8%) than in the CA group(21.4%). When an anastomosis was made by the stapled technique, smaller size of the staple increased the prevalence of stricture formation - 41.7% with 25-mm staple and 9.1% with 28-mm staple(p < 0.05). Conclusion: Wider resection margin could decrease the anastomotic tumor recurrence, and the stapled technique could decrease the anastomotic leak. The prevalence of benign stricture was higher in the cervical anastomosis but the anastomotic leak and smaller size(25-mm) of the staple should be considered as risk factors.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.1
• /
• pp.71-81
• /
• 2005

The purposes of this study was to collect, analyze, and describe the MF exposure levels from subways in Korea and to measure and evaluate the MF levels generated from electric appliances used at general homes. The target subway lines were Seoul Metropolitan Line 1 to Line 8, Bundang Line, Incheon Line, Daegu Line, Gwangju Line, and Busan Line 1 and Line 2. We measured at each station in those subway lines and, all the train types (pantograph-equipped, motor-equipped, and common), and platform types(facing and isolating) were investigated by the distance(80, 200, 400 cm) from the train on 19 targeted subway lines using 3 magnetic field measuring devices (EMDEXII, Enertech Co.) during the survey from January till October, 2004. On the other hand, the levels of the 60Hz magnetic fields generated from 14 items of home electric appliances such as electric blankets, hair dryers, electric razors, etc. were measured at 10 general homes using 5 EMDEXII meters with a sampling interval of 1.5 second by the distance(surface, 30, 50, 100, 300cm ) from the target electric appliances. The survey results in the whole subway lines examined in this study were as follows; Seoul Metropolitan Line 4 using AC(alternating current) power source showed the highest mean value of $2.85{\mu}T$, followed by Seoul Metropolitan Line 1 running between Seoul and Incheon using AC($2.78{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Uijongbu using AC($2.73{\mu}T$), Bundang Line using AC($1.79{\mu}T$), Seoul Metropolitan Line 1 connected from Yongsan using AC($1.67{\mu}T$), Seoul Metropolitan Line 1 between Seoul and Suwon using AC($0.79{\mu}T$), and so on. In general, the intensity of the magnetic field in the subway systems in Korea was significantly higher when using AC($2.14{\pm}0.91{\mu}T$) than when using DC($0.29{\pm}0.44{\mu}T$) power source. Among the home electric appliances examined, microwave ovens showed the highest mean value of $7.69{\mu}T$, followed by hair dryers($6.47{\mu}T$), vacuum cleaners($5.27{\mu}T$), televisions ($2.26{\mu}T$), electric blankets($1.38{\mu}T$), personal computers ($0.81{\mu}T$), and so on. Two items of electric appliances showed the excess value of $0.2{\mu}T$ at the distance of 30cm in the MF exposure level; electric razors $1.58{\pm}2.13{\mu}T$ and vacuum cleaners $0.48{\pm}0.44{\mu}T$. As a whole, this study showed a tendency that the shift of the MF levels according to the increase of distance from the electric appliances was lower than those of the results surveyed in UK and USA. As a result, this study is expected to suggest meaningful data for the future study in exposure assessment of magnetic fields and for the establishment of guidelines for subways and electric appliances in Korea. More detailed and large scaled exposure assessment studies should be performed continuously to get the various and useful information on health risk assessment of MFs in Korea.

• The Journal of the Petrological Society of Korea
• /
• v.21 no.1
• /
• pp.1-12
• /
• 2012

The Baegdusan volcano is one of the most active volcanoes in northeastern Asia, and the 10th century eruption was the most voluminous eruption in the world in recent 2,000 years. During the period from 2002 to 2005, volcanic earthquakes and abnormal surface distortions by suspected subsurface magma intrusion beneath the volcano were observed in the Baegdusan area. Seismic activity has gradually increased with earthquake swarms during 2002-2003 and hundreds of seismic event in a day, especially annual peak of 2,100 in 2003. Then the number of seismic activity has declined since 2006 to the background level in 1999-2001. According to the typical frequency of volcanic earthquakes in the Baegdusan volcano, the frequency distribution of typical volcanic earthquakes between 2002 and 2005 indicates that all the main frequency of the earthquakes basically falls down less than 5 Hz and 5-10 Hz. These events are all the VT-B and LP events caused by the shallow localized fracture and intrusion of magma. The horizontal displacement measurement by GPS during the period from 2000 to 2007 of the Baegdusan stratovolcano area indicates that an inflated process has been centered at the summit caldera since 2002. The displacement between 2002 and 2003 reached at a maximum value of 4 cm. After 2003, the deformation rate of the volcano continued to decrease with unusual variation during the period from 2006 to 2007. After 2003 the vertical displacement uplift rate falls down gradually but still keeps in an uplift trend in northern slope. It is generally believed that when $^3He/^4He(R)$ in a gas sample from a hot spring exceeds $^3He/^4He(R)$ in the atmosphere, it can be concluded that mantle-source. And temperatures of hot springs are rising steadily to $83^{\circ}C$. It is unrest signals at the Baegdusan, which is potentially active. The Baegdusan volcano is now in unrest status, there is eruption threat in the near future. Intensified monitoring and emergency response plan for volcanic risk mitigation are urgent for the volcano.

• Progress in Medical Physics
• /
• v.24 no.4
• /
• pp.295-302
• /
• 2013

We estimated secondary scattered and leakage doses for intensity-modulated radiotherapy (IMRT), volumetric arc therapy (VMAT) and tomotherapy (TOMO) in patients with liver cancer. Five liver patients were planned by IMRT, VMAT and TOMO. Secondary scatter (and leakage) dose and organ equivalent doses (OEDs) are measured and estimated at various points 20 to 80 cm from the iso-center by using radiophotoluminescence glass dosimeter (RPLGD). The secondary dose per Gy from IMRT, VMAT and TOMO for liver cancer, measured 20 to 80 cm from the iso-center, are 0.01~3.13, 0.03~2.34 and 0.04~1.29 cGy, respectively. The mean values of relative OED of secondary dose of VMAT and TOMO for five patients, which is normalized by IMRT, measured as 75.24% and 50.92% for thyroid, 75.14% and 40.61% for bowel, 72.30% and 47.77% for rectum, 76.21% and 49.93% for prostate. The secondary dose and OED from TOMO is relatively low to those from IMRT and VMAT. OED based estimation suggests that the secondary cancer risk from TOMO is less than or comparable to the risks from conventional IMRT and VMAT.

• Journal of Chest Surgery
• /
• v.42 no.2
• /
• pp.201-205
• /
• 2009

Background: Cryosurgery has been used to treat primary malignant pulmonary tumors at our institute since November 2004. In this study we analyzed our treatment results and complication rates. Material and Method: A retrospective study using medical charts and imaging data was conducted involving 17 patients with a total of 17 malignant pulmonary tumors who were treated between November 2004 and March 2007. Fourteen patients were males and 3 were females. The median age of the patients was 64 years (range, $54{\sim}77$ years). The average size of the tumors was 48.8mm (range, $36{\sim}111mm$) in diameter. The patients were followed with chest CT scans 7 days, 1 month, 3 months, and 6 months postoperatively. PET scans were obtained between 6 and 9 months postoperatively. The treatment response was analyzed according to the Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Result: Six months after treatment, 6 tumors (35.3%) showed a complete response, 4 (23.5%) had a partial response, 3 (17.6%) had stable disease, and 4 (23.5%) showed disease progression. In tumors <4 cm in diameter, a complete response was reported in 50% of the tumors. A $x^2$-test showed that in tumors <4 cm in diameter, the p-value for results better than a partial response was 0.034. With respect to procedural complications, there was 1 case of blood-tinged sputum which resolved spontaneously within 1 or 2 days, a spontaneously relieved case of subcutaneous emphysema, and 1 patient with a fever. There were no mortalities and the average hospital stay was 6.3 days. Conclusion: The effects of cryosurgery on primary lung cancer is greatest in patients with small tumors. Considering the facts that cryosurgery is minimally invasive, has a low complication rate, and can be performed repetitively, we believe that it may play an important role in the treatment of high risk lung cancer patients.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.9
• /
• pp.4033-4037
• /
• 2014

Emerging evidence has shown associations of microRNA-205 (miR-205) with crucial cell processes such as the epithelial-mesenchymal transition (EMT) and aberrant expression with tumorigenesis in many types of human malignancy. This prospective study characterized the contribution of miR-205 to the colorectal cancer (CRC) tumorigenesis. The real-time reverse transcription-polymerase chain reaction was used to examine miR-205 levels prospectively in 36 pairs of samples of CRC tissue and adjacent noncancerous tissue (>2 cm from cancer tissue). In addition, the relationship between miR-205 levels and clinicopathological features was explored. The capability of miR-205 to function as a tumor marker was also examined. miR-205 expression levels did not show significant changes overall. However, miR-205 was significantly downregulated in a group of CRC samples compared with matched noncancerous tissue samples. Moreover, decreased miR-205 correlated significantly with lymphatic metastasis. A receiver operating characteristic (ROC) curve also showed an optimum cut off point of $1.4{\times}10^{-3}$ to distinguish lymphatic metastatic CRCs from non-metastatic CRCs. Interestingly we found lymphatic metastasis in almost 80% of the depressed samples. This study suggested that miR-205 could be reduced in the majority of metastatic CRCs and the risk of CRC metastasis may be predicted by monitoring miR-205 in patient samples collected at the time of the initial diagnosis. Therefore, targeting miR-205 and its potential environmental activators might be a promising therapeutic option to prevent malignant progression toward metastasis.

• Proceedings of the KIEE Conference
• /
• 2004.11c
• /
• pp.532-534
• /
• 2004

The advancement of electronics and telecommunication technologies has forced the risk management system for underground metallic structures to evolve into the remote monitoring and control system. Especially, facilities such as gas pipelines, oil pipelines and water distribution lines might make hazardous effect on human safety without continuous monitoring and control. As a result, pipeline engineers have applied cathodic protection system to prevent the degradation of their facilities by corrosion and carried out a periodic monitoring of the pipe-to-soil (P/S) potentials at numberous test boxes along their pipelines. The latter action on a road in downtowns, however, is so much dangerous that the inspectors should be ready to suffer the threatening of their lives and maintenance. In order to minimize these social costs and hazards, a stand-alone type corrosion monitoring equipment which can be installed in test box, store the P/S data for given Belied and send the data by wired/wireless telecommunications is under development. In order to obtain the exact P/S data, however, a reference electrode should be located as close to the pipeline as possible. Actually, the measured potential by a conventional portable reference electrode contain inevitably an IR drop portion caused by the current flow from the cathodic protection rectifier or the subway railroad. To minimize this error, it is recommended that the reference electrode should be buried within 10 cm from the pipeline. In this paper, we describe the design parameters for fabricating the permanent type reference electrode and the characteristics of the developed reference electrode.