• Radiation Oncology Journal
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• v.17 no.3
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• pp.209-216
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• 1999

Purpose : To evaluate the effectiveness of external radiation therapy and the prognostic factors, we retrospectively analyzed therapeutic results of malignant extrahepatic biliary obstruction (EHBO). Methods and Materials : We analyzed the results of the external radiation therapy in 59 patients of inoperable malignant EHBO who had been treated with more than 10 Gy of external radiation therapy from April 1984 to December 1990. There were 21 stomach cancer ($35.6\%$), 12 pancreas cancer ($20.3\%$), 15 extrahepatic biliary cancer ($18.0\%$) and 11 another cancer ($18.0\%$). Their pathologies were confirmed in 31 patients ($52.5\%$). They divided into 27 adenocarcinoma and 4 nonadenocarcinoma. Their chief complaints were jaundice in 47 patients ($79.7\%$) and abdominal pain in 15 patients ($49.2\%$). Twelve patients had slightly increased bilirubin level in liver function test without jaundice. We treated twenty four patients ($40.6\%$) with percutaneous transhepatic biliary drainage (PTBD) and 32 patients ($54\%$) with systemic chemotherapy (CT). We performed external radiation therapy (ERT) upto $10.8\~55.8$ Gy (median 37.8 Gy) with palliative aim. Results : Overall median survival duration was $7.80\pm1.15$ months. The response rates of jaundice were $81.8\%$ in PTBO group and $66.7\%$ in non-PTBD group without statistical significance. The improving rate of jaundice was not significantly different in decreased ratio of total bilirubin level. But abdominal pain was more decreased in CT group than non-CT group (p<0.05). The significant prognostic factors were high performance status (Karnofski Performance Status >70), total radiation dose more than 35 Gy and good response of pain after therapy. There were increased in bacterial cholagitis in PTBD group and gastrointestinal complications in CT group. Conclusion : External radiotheapy could improve jaundice and abdominal pain in malignant EHBO patients, Overall survival duration was prolonged in patients with higher performance status and patients who had been treated with more than 35 Gy of total radiation dose. In the future, we expect not only better palliative role but also the prolongation of survival of using the ERT combined with other treatment method. But to achieve certain conclusion, we need luther study consisted with many kinds of treatment methods including new technologies in RT.

• Progress in Medical Physics
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• v.23 no.2
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• pp.91-98
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• 2012

Verification of internal organ motion during treatment and its feedback is essential to accurate dose delivery to the moving target. We developed an offline based internal organ motion verification system (IMVS) using cine EPID images and evaluated its accuracy and availability through phantom study. For verification of organ motion using live cine EPID images, a pattern matching algorithm using an internal surrogate, which is very distinguishable and represents organ motion in the treatment field, like diaphragm, was employed in the self-developed analysis software. For the system performance test, we developed a linear motion phantom, which consists of a human body shaped phantom with a fake tumor in the lung, linear motion cart, and control software. The phantom was operated with a motion of 2 cm at 4 sec per cycle and cine EPID images were obtained at a rate of 3.3 and 6.6 frames per sec (2 MU/frame) with $1,024{\times}768$ pixel counts in a linear accelerator (10 MVX). Organ motion of the target was tracked using self-developed analysis software. Results were compared with planned data of the motion phantom and data from the video image based tracking system (RPM, Varian, USA) using an external surrogate in order to evaluate its accuracy. For quantitative analysis, we analyzed correlation between two data sets in terms of average cycle (peak to peak), amplitude, and pattern (RMS, root mean square) of motion. Averages for the cycle of motion from IMVS and RPM system were $3.98{\pm}0.11$ (IMVS 3.3 fps), $4.005{\pm}0.001$ (IMVS 6.6 fps), and $3.95{\pm}0.02$ (RPM), respectively, and showed good agreement on real value (4 sec/cycle). Average of the amplitude of motion tracked by our system showed $1.85{\pm}0.02$ cm (3.3 fps) and $1.94{\pm}0.02$ cm (6.6 fps) as showed a slightly different value, 0.15 (7.5% error) and 0.06 (3% error) cm, respectively, compared with the actual value (2 cm), due to time resolution for image acquisition. In analysis of pattern of motion, the value of the RMS from the cine EPID image in 3.3 fps (0.1044) grew slightly compared with data from 6.6 fps (0.0480). The organ motion verification system using sequential cine EPID images with an internal surrogate showed good representation of its motion within 3% error in a preliminary phantom study. The system can be implemented for clinical purposes, which include organ motion verification during treatment, compared with 4D treatment planning data, and its feedback for accurate dose delivery to the moving target.

• Radiation Oncology Journal
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• v.25 no.1
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• pp.16-25
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• 2007

[ $\underline{Purpose}$ ]: Breast conserving surgery (BCS) followed by chemotherapy (CTx.) and radiation therapy (RT) is widely performed for the treatment of early breast cancer. This retrospective study was undertaken to evaluate our interim results in terms of failure patterns, survival and relative risk factors. $\underline{Materials\;and\;Methods}$: From January 1999 through December 2003, 129 patients diagnosed with invasive breast cancer and treated with BCS followed by RT were subject to retrospective review. The median age of the patients was 45 years (age distribution, $27{\sim}76$ years). The proportions of patients according to their tumor, nodes, and metastases (TNM) stage were 65 (50.4%) in stage I, 41 (31.7%) in stage IIa, 13 (10.1%) in stage IIb, 9 (7.0%) in stage III, and 1 patient (0.8%) in stage IIIc. For 32 patients (24.8%), axillary node metastasis was found after dissection. BCS consisted of quadrantectomy in 115 patients (89.1%) and lumpectomy in 14 patients (10.6%). Axillary node dissection at axillary level I and II was performed for 120 patients (93%). For 7 patients (5.4%), only sentinel node dissection was performed with BCS. For 2 patients (1.6%) axillary dissection of any type was not performed. Postoperative RT was given with 6 MV X-rays. A tumor dose of 50.4 Gy was delivered to the entire breast area using a tangential field with a wedge compensator. An aditional dose of $9{\sim}16\;Gy$ was given to the primary tumor bed areas with electron beams. In 30 patients (23.3%), RT was delivered to the supraclavicular node. Most patients had adjuvant CTx. with $4{\sim}6$ cycles of CMF (cyclophosphamide, methotrexate, 5-fluorouracil) regimens. The median follow-up period was 50 months (range: $17{\sim}93$ months). $\underline{Results}$: The actuarial 5 year survival rate (5Y-OSR) was 96.9%, and the 5 year disease free survival rate (5Y-DFSR) was 93.7%. Local recurrences were noted in 2 patients (true: 2, regional node: 1) as the first sign of recurrence at a mean time of 29.3 months after surgery. Five patients developed distant metastases as the first sign of recurrence at $6{\sim}33$ months (mean 21 months). Sites of distant metastatic sites were bone in 3 patients, liver in 1 patient and systemic lesions in 1 patient. Among the patients with distant metastatic sites, two patients died at 17 and 25 months during the follow-up period. According to stage, the 5Y-OSR was 95.5%, 100%, 84.6%, and 100% for stage I, IIa, IIb, and III respectively. The 5Y-DFSR was 96.8%, 92.7%, 76.9%, and 100% for stage I, IIa, IIb, and III respectively. Stage was the only risk factor for local recurrence based on univariate analysis. Ten stage III patients included in this analysis had a primary tumor size of less than 3 cm and had more than 4 axillary lymph node metastases. The 10 stage III patients received not only breast RT but also received posterior axillary boost RT to the supraclavicular node. During the median 53.3 months follow-up period, no any local or distant failure was found. Complications were asymptomatic radiation pneumonitis in 10 patients, symptomatic pneumonitis in 1 patient and lymphedema in 8 patients. $\underline{Conclusion}$: Although our follow up period is short, we had excellent local control and survival results and reaffirmed that BCS followed by RT and CTx. appears to be an adequate treatment method. These results also provide evidence that distant failure occurs earlier and more frequent as compared with local failure. Further studies and a longer follow-up period are needed to assess the effectiveness of BCS followed by RT for the patients with less than a 3 cm primary tumor and more than 4 axillary node metastases.

• Radiation Oncology Journal
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• v.19 no.2
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• pp.100-106
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• 2001

Purpose : We performed a retrospective analysis to compare short term results of induction chemotherapy-radiotherapy versus concurrent chemo-radiotherapy in patients with locally advanced nasopharyngeal carcinoma. Materials and Methods : From Oct. 1989 to May 1998, 62 patients with locally advanced nasopharyngeal carcinoma were treated with induction chemotherapy followed by radiotherapy (induction group) or concurrent chemo-radiotherapy (concurrent group). Induction chemotherapy was done for 50 patients, and concurrent chemotherapy for 12 patients. Age, sex, performance status, and pathologic types were evenly distributed between two groups. Stage distribution showed $32\%$ with IIB, $32\%$ with III, and $38\%$ with IV in induction group, and $50\%,\;33.3\%,\;and\;16.7\%$ in concurrent group, respectively. Chemotherapy regimen was CF (cisplatin and 5-FU) in both groups, and drug delivery method also same. Cisplatin $100\;mg/m^2$ was intravenously infused on day 1, and 5-FU $1,000\;mg/m^2$ on day $2\~6$. This was repeated at 3 weeks interval. At the end of radiotherapy, total cycles of chemotherapy were $1\~3$ (median 2) in both groups. Conventionally fractionated radiotherapy with daily fraction size $1.8\~2.0\;Gy$ and 5 fractions/week was done. Total dose was $69.4\~86\;Gy$(median 73.4 Gy) for induction group, and $69.4\~75.4\;Gy$ (median 70.8 Gy) for concurrent group. Follow-up time was $9\~116$ months (median 40.5 months) for induction group, $14\~29$ months (median 21 months) for concurrent group, respectively. Results : Overall 2 year survival rate (2YSR) for all patients was $78.7\%$. According to treatment modality, 2YSR were $77\%$ for induction group, $87\%$ for concurrent group (p>0.05). 2 year disease-free survival rate were $56\%$ and $81\%\;(p>0.05)$, respectively. Complete response to treatment were $75.5\%$ for induction group and $91.7\%$ for concurrent group, but there was no statistical difference. The incidence of grade $3\~4$ hematologic toxicity during radiotherapy was not differ between two groups, but grade 2 leukopenia was more frequent in concurrent group $(18\%\;vs\;66.7\%)$Grade $3\~4$ mucositis was more frequent in concurrent group $(4.0\%\;vs\;33.3\%)$. Overall incidence of grade $3\~4$ acute toxicity during radiotherapy was more frequent in concurrent group $(6.0\%\;vs\;41.7\%,\;p=0.005)$. Conclusion : Concurrent chemo-radiotherapy showed a trend of improvement in short-term survival and in treatment response when compared with induction chemotherapy-radiotherapy in locally advanced nasopharyngeal carcinoma. More controlled randomized trial are needed.

• Radiation Oncology Journal
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• v.27 no.3
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• pp.126-132
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• 2009

Purpose: We wanted to evaluate the prognostic factors for the pathologic N2 non-small cell lung cancer (NSCLC) patients who were treated by postoperative radiotherapy. Materials and Methods: We retrospectively reviewed 112 pN2 NSCLC patients who underwent surgery and postoperative radiotherapy (PORT) From January 1999 to February 2008. Seventy-five (67%) patients received segmentectomy or lobectomy and 37 (33%) patients received pneumonectomy. The resection margin was negative in 94 patients, and it was positive or close in 18 patients. Chemotherapy was administered to 103 (92%) patients. Nine (8%) patients received PORT alone. The median radiation dose was 54 Gy (range, 45 to 66), and the fraction size was 1.8~2 Gy. Results: The 2-year overall survival (OS) rate was 60.2% and the disease free survival (DFS) rate was 44.7% for all the patients. Univariate analysis showed that the patients with multiple-station N2 disease had significantly reduced OS and DFS (p=0.047, p=0.007) and the patients with an advanced T stage ($\geq$T3) had significantly reduced OS and DFS (p<0.001, p=0.025). A large tumor size ($\geq$5 cm) and positive lymphovascular invasion reduced the OS (p=0.035, 0.034). Using multivariate analysis, we found that multiple-station N2 disease and an advanced T stage ($\geq$T3) significantly reduced the OS and DFS. Seventy one patients (63.4%) had recurrence of disease. The patterns of failure were loco-regional in 23 (20.5%) patients, distant failure in 62 (55.4%) and combined loco-regional and distant failure in 14 (12.5%) patients. Conclusion: Multiple involvement of mediastinal nodal stations for the pN2 NSCLC patients with PORT was a poor prognostic factor in this study. A prospective study is necessary to evaluate the N2 subclassification and to optimize the adjuvant treatment.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.204-212
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• 2008

Purpose: This study was performed to evaluate the disease-free survival and risk factors of recurrence in early breast cancer patients who have undergone breast conserving surgery and radiation therapy. Materials and Methods: From March 1997 to December 2002, 77 breast cancer patients who underwent breast conserving surgery and radiation therapy were reviewed retrospectively. The median follow-up time was 58.4 months (range $43.8{\sim}129.4$ months) and the mean subject age was 41 years. The frequency distribution of the different T stages, based on the tumor characteristics was 38 (49.3%) for T1, 28 (36.3%) for T2, 3 for T3, 7 for T is and 1 for an unidentified sized tumor. In addition, 52 patients (67.5%) did not have axillary lymph metastasis, whereas 14 patients (18.1%) had $1{\sim}3$ lymph node metastases and 3 (0.03%) had more than 4 lymph node metastases. The resection margin was negative in 59 patients, close (${\leq}2\;mm$) in 15, and positive in 4. All patients received radiation therapy at the intact breast using tangential fields with a subsequent electron beam boost to the tumor bed at a total dose ranging from 59.4 Gy to 66.4 Gy. Patients with more than four positive axillary lymph nodes received radiation therapy ($41.4{\sim}60.4\;Gy$) at the axillary and supraclavicular area. Chemotherapy was administered in 59 patients and tamoxifen or fareston was administered in 29 patients. Results: The 5 year overall survival and disease-free survival rates were 98.08% and 93.49%, respectively. Of the 77 patients, a total of 4 relapses (5.2%), including 1 isolated supraclavicular relapse, 1 supraclavicular relapse with synchronous multiple distant relapses, and 2 distant relapses were observed. No cases of local breast relapses were observed. Lymph node metastasis or number of metastatic lymph nodes was not found to be statistically related with a relapse (p=0.3289) nor disease-free survival (p=0.1430). Patients with positive margins had a significantly shorter disease-free survival period (p<0.0001) and higher relapse rates (p=0.0507). However, patients with close margins were at equal risk of relapse and disease-free survival as with negative margins (p=1.000). Patients younger than 40 years of age had higher relapse rates (9.3% vs. 0%) and lower disease-free survival periods, but the difference was not statistically significant (p=0.1255). The relapse rates for patients with tumors was 14% for tumor stage T2, compared to 0% for tumor stage T1 tumors (p=0.0284). A univariate analysis found that disease-free survival and relapse rates, T stage, positive resection margin and mutation of p53 were significant factors for clinical outcome. Conclusion: The results of this study have shown that breast conservation surgery and radiation therapy in early breast cancer patients has proven to be a safe treatment modality with a low relapse rate and high disease-free survival rate. The patients with a positive margin, T2 stage, and mutation of p53 are associated with statistically higher relapse rates and lower disease-free survival.

• Radiation Oncology Journal
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• v.20 no.3
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• pp.221-227
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• 2002

Purpose : To evaluate the role of postoperative chemoradiotherapy in locally advanced rectal cancer, we retrospectively analyzed the treatment results of patients treated by curative surgical resection and postoperative chemoradiotherapy. Materials and Methods : From April 1989 through December 1998, 119 patients were treated with curative surgery and postoperative chemoradiotherapy for rectal carcinoma in Gyeongsang National University Hospital. Patient age ranged from 32 to 73 years, with a median age of 56 years. Low anterior resection was peformed in 59 patients, and abdominoperineal resection in 60. Forty-three patients were AJCC stage II and 76 were stage III. Radiation was delivered with 6 MV X rays using either AP-PA two fields, AP-PA both lateral four fields, or PA both lateral three fields. Total radiation dose ranged from 40 Gy to 56 Gy. In 73 patients, bolus infusions of 5-FU $(400\;mg/m^2)$ were given during the first and fourth weeks of radiotherapy. After completion of radiotherapy, an additional four to six cycles of 5-FU were given. Oral 5-FU (Furtulone) was given for nine months in 46 patients. Results : Forty $(33.7\%)$ of the 119 patients showed treatment failure. Local failure occurred in 16 $(13.5\%)$ patients, 1 $(2.3\%)$ of 43 stage II patients and 15 $(19.7\%)$ of 76 stage III patients. Distant failure occurred in 31 $(26.1\%)$ patients, among whom 5 $(11.6\%)$ were stage II and 26 $(34.2\%)$ were stage III. Five-year actuarial survival was $56.2\%$ overall, $71.1\%$ in stage II patients and $49.1\%$ in stage III patients (p=0.0008). Five-year disease free survival was $53.3\%$ overall, $68.1\%$ in stage II and $45.8\%$ in stage III (p=0.0006). Multivariate analysis showed that T stage and N stage were significant prognostic factors for five year survival, and that T stage, N stage, and preoperative CEA value were significant prognostic factors for five year disease free survival. Bowel complication occurred in 22 patients, and was treated surgically in 15 $(12.6\%)$, and conservatively in 7 $(5.9\%)$. Conclusion : Postoperative chemoradiotherapy was confirmed to be an effective modality for local control of rectal cancer, but the distant failure rate remained high. More effective modalities should be investigated to lower the distant failure rate.

• Radiation Oncology Journal
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• v.19 no.3
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• pp.216-223
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• 2001

Purpose : We evaluated retrospectively the outcomes of inoperable squamous cell lung cancer patients treated with radiotherapy to find out prognostic factors affecting survival. Materials and methods : Four hundred and eleven patients diagnosed as squamous cell lung cancer between November 1988 and December 1997 were the basis of this analyses. The planned dose to the gross tumor volume was ranged from 30 to 70.2 Gy. Chemotherapy was combined in 72 patients $(17.5\%)$ with the variable schedule and drug combination regimens. Follow-up period ranged from 1 to 113 months with the median of 8 months and survival status was identified in 381 patients $(92.7\%)$. Overall survival rate was calculated using the Kaplan-Meier method. Results : Age ranged from 23 years to 83 years with the median 63 years. The male to female ratio was about 16:1. For all 411 patients, the median overall survival was 8 months and the 1-year survival rate (YSR), 2-YSR, and 5-YSR were $35.6\%,\;12.6\%,\;and\;3.7\%$, respectively. The median and 5-YSR were 29 months and $33.3\%$ for Stage IA, 13 months and $6.3\%$ for Stage IIIA, and 9 months and $3.4\%$ for Stage IIIB, respectively(p=0.00). The median survival by treatment aim was 11 months in radical intent group and 5 months in palliative, respectively (p=0.00). Of 344 patients treated with radical intent, median survival of patients (N=247) who received planned radiotherapy completely was 12 months while that of patients (N=97) who did not was 5 months (p=0.0006). In the analyses of the various prognostic factors affecting to the survival outcomes in 247 patients who completed the planned radiotherapy, tumor location, supraclavicular LAP, SVC syndrome, pleural effusion, total lung atelectasis and hoarseness were statistically significant prognostic factors both in the univariate and multivariate analyses while the addition of chemotherapy was statistically significant only in multivariate analyses. The acute radiation esophagitis requiring analgesics was appeared in 49 patients $(11.9\%)$ and severe radiation esophagitis requiring hospitalization was shown in 2 patients $(0.5\%)$. The radiation pneumonitis requiring steroid medication was shown in 62 patients $(15.1\%)$ and severe pneumonitis requiring hospitalization was occurred in 2 patients $(0.5\%)$. During follow-up, 114 patients $(27.7\%)$ had progression of local disease with 10 months of median time to recur (range : $1\~87\;months$) and 49 patients $(11.9\%)$ had distant failure with 7 months of median value (range : $1\~52\;months$). Second malignancy before or after the diagnosis of lung cancer was appeared in 11 patients Conclusion : The conventional radiotherapy in the patients with locally advanced squamous cell lung cancer has given small survival advantage over supportive care and it is very important to select the patient group who can obtain the maximal benefit and to select the radiotherapy technique that would not compromise the life quality in these patients.

• Korean Journal of Veterinary Service
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• v.23 no.4
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• pp.321-333
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• 2000

In order to know the depletive changes of sulfamethazine residues in senlm and practical organs of rats orally administered with sulfamethazine sodium(SMS), the concentration of sulfamethazine was measured in serum and tissue(kidney, liver, spleen, testis, and skeletal muscle) of rats with using high performance liquid chromatography(HPLC). SMS was orally administrated to sprague-dawley male rats(body weight, 200~300g) with using sonde at the rate of 20mg/100g body weight(recommended therapeutic dose) on once a day for 3 days. There were investigated the depletive changes of the sulfamethazine in serum, kidney, liver, spleen, testis and skeletal muscle of rat at the time 8 hours, 1st, 2nd, 3rd, 4th, 5th and 6th day after administration SMS, respectively. The results obtained were summarized as follows; 1. After oral administration of the SMS, the mean concentrations of sulfamethazine in serum according to the time lapsed were showed 215.53$\pm$42.99ppm at the 8 hours after withdrawal of medicated sulfamethazine. And gradually according to the time lapsed, the concentrations of sulfamethazine residues in serum were significantly (p<.05) decreased 25.87$\pm$5.18ppm at 1st day, 2.30$\pm$0.61ppm at 3rd day and 0.11$\pm$0.02ppm at 6th day respectively. 2. The mean concentrations of sulfamethazine in kidney, liver, spleen, muscle and testis according to the time lapsed after administration SMS were showed 83.82$\pm$12.16, 81.77$\pm$12.88, 36.96$\pm$5.35, 35.96$\pm$TEX>$\pm$1.39 and 27.89$\pm$1.92 ppm at the 8 hours, respectively. And gradually according to the time lapsed, the concentrations of sulfamethazine residues in the each of samples were significantly(p<.05) decreased such as 7.15$\pm$0.26, 5.62$\pm$0.72, 2.43$\pm$0.29, 1.99$\pm$0.14 and 3.11$\pm$0.48 ppm at 1st day, 0.52$\pm$0.04, 1.32$\pm$0.22, 0.13$\pm$0.03, 0.15$\pm$0.06 and 0.26$\pm$0.11ppm at 3rd day, and 0.03$\pm$0.01, 0.11$\pm$0.03, 0.02$\pm$0.01, 0.009$\pm$0.001 and 0.02$\pm$0.01 ppm at 6th day, respectively. 3. After oral administration of the SMS to rats, the residual concentrations of sulfamethazine in skeletal muscle were significantly (p<.05) decreased 35.96$\pm$1.39 to 0.009$\pm$$\pm$0.001 ppm between 8 hours and 6th day, respectively From the 4th day, the residual concentrations of sulfamethazine were showed 0.10$\pm$0.04 ppm below 0.1 ppm at the permitted limit concentration of muscle in Korea. In conclusion, this study could be suggested the relationship between administrated period, doses of sulfonamides and residual aspects of serum and practical organs, and the importance of observing ceasing period of antibiotic drugs before forwarding livestocks to slaughter.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.305-313
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• 2015

After Fukushima Daiichi nuclear disaster in 2011, study and maintenance of monitoring systems have been made at home and abroad. As concerns about radioactive contamination of water have increased in Korea, update of maintenance of managing radioactive materials in water is being made mainly by Ministry of Environment. In this study, we analysed current state of monitoring system modification in Japan, the country directly involved and neighboring country. According to the result, Japan modified the legislations first. Then Ministry of Education, Culture, Sports, Science and Technology (MEXT) provides theoretical background of radiological monitoring. And Ministry of the Environment actually watches state of water pollution in public waters and underground water. Finally related agencies like local government are monitoring current state of radioactive contamination in water environment. By region, local monitoring stations share the investigation of the whole country. Also, additional monitoring is running around nuclear facilities. After Fukushima disaster, monitoring for area near Fukushima is added. Among the reference levels, management target value of drinking water and tap water is 10 Bq/kg, and those of public water and underground water are 1 Bq/L. Measuring intervals varied from every hour to once a year, regularly or irregularly depending on the investigation. The main measuring items are air dose rate, gross ${\alpha}$, gross ${\beta}$, ${\gamma}$ radionuclide, Cs-134, Cs-137, Sr-89, Sr-90, I-131, and so on. In comparison, regulations about general public water in Korea need to be modified, while those about area near nuclear facility and drinking water are organized well. In future, therefore, domestic system would be expected to be modified with making reference to the guidelines like WHO's one. As good case of applying international guideline to domestic environment, Japanese system could be a reference when general standard of radioactivity in public water is made in Korea.