• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.291-303
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• 2020

The Kori-Unit 1 nuclear power plant, which is scheduled to be decommissioned after permanent shutdown, is expected to generate large amounts of various types of radioactive waste during the decommissioning process. Among these, nuclear reactors and internal structures have high levels of radioactivity and the dismantled structure must have the proper size and weight on the primary side. During decommissioning, it is important to prepare an appropriate and efficient disposal method through analysis of the disposal status and the legal restrictions on wastes generated from the reactors and internal structures. Nuclear reactors and internal structures generate radioactive wastes of various levels, such as medium, very low, and clearance. A radiation evaluation indicates that wastes in the clearance level are generated in the reactor head and upper head insulation. In this study, a clearance waste safety evaluation was conducted using the RESRAD-RECYCLE code, which is a safety evaluation code, based on the activation evaluation results for the clearance level wastes. The clearance scenario for the target radioactive waste was selected and the maximum individual and collective exposure doses at the time of clearance were calculated to determine whether the clearance criteria limit prescribed by the Nuclear Safety Act was satisfied. The evaluation results indicated that the doses were significantly low, and the clearance criteria were satisfied. Based on the safety assessment results, an appropriate metal recycle and disposal method were suggested for clearance, which are the subject of the deregulation of internal structures of nuclear power plant.

• The Korean Journal of Nuclear Medicine
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• v.8 no.1_2
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• pp.29-37
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• 1974

The $^{99m}Tc$-pertechnetate thyroid uptake rates(20 min) were measured in 24 healthy normal subjects, 140 patients with nontoxic goiter and 98 patients with thyrotoxicosis who were treated at the Thyroid Clinic, Seoul National University Hospital, from August 1972 to August 1973. Diagnostic reliabilities and correlations between $^{99m}TcO_4$-thyroid uptake rate (20 min) and other thyroid function tests were evaluated. The observed results were as follows 1. The $^{99m}TcO_4$-thyroid uptake rates (20 min) in normal subjects, euthyroid group and hyperthyroid group were $4.1{\pm}0.9%,\;5.2{\pm}1.8%\;and\;29.7{\pm}10.6%$. There was a significant difference between the mean of the euthyroid group and the mean of the hyperthyroid group and so differentiation between them can be easy. 2. In the diagnosis of hyperthyroidism, the reliabilities of $^{99m}TcO_4$- thyroid uptake rate(20 min), $^{131}I$ thyroid uptake rate(24hrs), serum $T_3$ resin uptake rate, serum $T_4\;and\;T_7\;were\;87.9{\sim}97.9%,\;81.2{\sim}94.4%,\;87.9{\sim}97.9%,\;90.5{\sim}99.3%\;and\;93.7{\sim}100%$. $^{99m}TcO_4$-thyroid uptake rate(20 min) is more accurate than $^{131}I$ thyroid uptake rate (24 hrs) in the diagnosis of hyperthyroidism. 3. $^{99m}TcO_4$-thyroid uptake rate (20 min) was well correlated with $^{131}I$ thyroid uptake rate (24 hrs), serum $T_3$ resin uptake rate, serum $T_4\;and\;T_7$. Points in favor of $^{99m}Tc$ are that it gives a small radiation dose to the thyroid, that tests can be repeated at the short interval, the study can be completed at a single patient visit and it is particularly well suited for the assessment of thyroid function in patients being treated with an antithyroid drug.

• 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.26 no.2
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• pp.83-90
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• 2008

Purpose: For the first time, a nationwide survey of the Patterns of Care Study(PCS) for the various radiotherapy treatments of esophageal cancer was carried out in South Korea. In order to observe the different parameters, as well as offer a solid cooperative system, we compared the Korean results with those observed in the United States(US) and Japan. Materials and Methods: Two hundreds forty-six esophageal cancer patients from 21 institutions were enrolled in the South Korean study. The patients received radiation theraphy(RT) from 1998 to 1999. In order to compare these results with those from the United States, a published study by Suntharalingam, which included 414 patients[treated by Radiotherapy(RT)] from 59 institutions between 1996 and 1999 was chosen. In order to compare the South Korean with the Japanese data, we choose two different studies. The results published by Gomi were selected as the surgery group, in which 220 esophageal cancer patients were analyzed from 76 facilities. The patients underwent surgery and received RT with or without chemotherapy between 1998 and 2001. The non-surgery group originated from a study by Murakami, in which 385 patients were treated either by RT alone or RT with chemotherapy, but no surgery, between 1999 and 2001. Results: The median age of enrolled patients was highest in the Japanese non-surgery group(71 years old). The gender ratio was approximately 9:1(male:female) in both the Korean and Japanese studies, whereas females made up 23.1% of the study population in the US study. Adenocarcinoma outnumbered squamous cell carcinoma in the US study, whereas squamous cell carcinoma was more prevalent both the Korean and Japanese studies(Korea 96.3%, Japan 98%). An esophagogram, endoscopy, and chest CT scan were the main modalities of diagnostic evaluation used in all three countries. The US and Japan used the abdominal CT scan more frequently than the abdominal ultrasonography. Radiotherapy alone treatment was most rarely used in the US study(9.5%), compared to the Korean(23.2%) and Japanese(39%) studies. The combination of the three modalities(Surgery+RT+Chemotherapy) was performed least often in Korea(11.8%) compared to the Japanese(49.5%) and US(32.8%) studies. Chemotherapy(89%) and chemotherapy with concurrent chemoradiotherapy(97%) was most frequently used in the US study. Fluorouracil(5-FU) and Cisplatin were the most preferred drug treatments used in all three countries. The median radiation dose was 50.4 Gy in the US study, as compared to 55.8 Gy in the Korean study regardless of whether an operation was performed. However, in Japan, different median doses were delivered for the surgery(48 Gy) and non-surgery groups(60 Gy). Conclusion: Although some aspects of the evaluation of esophageal cancer and its various treatment modalities were heterogeneous among the three countries surveyed, we found no remarkable differences in the RT dose or technique, which includes the number of portals and energy beams.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.98-103
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• 2014

Purpose: The effective half life of I-131 is useful to calculate radiation dose, period of hospitalization, and exposure dose of surrounding people from patient. However, it is difficult to measure. This study estimates the effective half life in whole body and thyroid in using of value of residual radioactivity obtained from the early and delay images of Dual time I-131 whole body scan. Also, the correlations between the effective half life and serum creatinine, GFR, and administration dose were investigated in this study. Materials and Methods: The targets were 50 patients administration high dose of I-131 from February to August in 2013, having normal range of serum creatinine and over $30{\mu}IU/mL$ of TSH levels. After administration radioactive I-131, the early scan in the 3rd day and the delay scan in the 5-6th days were performed. To measure the residual radioactivity in the whole body and thyroid, ROI was set and then background radioactivity was corrected to estimate. The effective half life was estimated by calculating the ratio of measured values between the early and delay images. To compare the effective half lives of the whole body and thyroid, it was analyzed by Independent t-test, and each correlation of the effective half life, GFR, serum creatinine, and the dose of administration were analyzed by calculating the pearson's correlation coefficient. All of the analysis were determined to be statistically significant when P<0.05. Results: The effective half life of the whole body was $17.06{\pm}5.50$ hours and of the thyroid was $17.22{\pm}5.41$ hours. The two effective half life did not show significant difference (P=0.887). As the value of GFR was increased, the effective half life of whole body (r=-0.407, P=0.003) and of thyroid (r=-0.473, P=0.001) were significantly decreased; as the value of serum creatinine was increased, the effective half life of whole body (r=0.309, P=0.029) and of thyroid (r=0.371, P=0.008) were significantly increased. In the administration dose, effective half life did not have correlations. Conclusion: The effective half life of I-131 of patients treated for their thyroids were estimated only by using the images of Dual time I-131 whole body scan. Also, the correlations with the effective life, GFR, and serum creatinine were examined. This study might be utilized for a study on optimization for the period of hospitalization of patients treated by high dose of I-131 and on evaluation for internal absorbed dose of MIRD schema in application of the effective half life.

• The Journal of Korean Society for Radiation Therapy
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• v.19 no.2
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• pp.99-106
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• 2007

Purpose: The patient's position and anatomy during the treatment course little bit varies to some extend due to setup uncertainties and organ motions. These factors could affected to not only the dose coverage of the gross tumor but over dosage of normal tissue. Setup uncertainties and organ motions can be minimized by precise patient positioning and rigid immobilization device but some anatomical site such as prostate, the internal organ motion due to physiological processes are challenge. In planning procedure, the clinical target volume is a little bit enlarged to create a planning target volume that accounts for setup uncertainties and organ motion as well. These uncertainties lead to differences between the calculated dose by treatment planning system and the actually delivered dose. The purpose of this study was to evaluate the differences of interfractional displacement of organ and GTV based on the tomoimages. Materials and Methods: Over the course of 3 months, 3 patients, those who has applied rectal balloon, treated for prostatic cancer patient's tomoimage were studied. During the treatment sessions 26 tomoimages per patient, Total 76 tomoimages were collected. Tomoimage had been taken everyday after initial setup with lead marker attached on the patient's skin center to comparing with C-T simulation images. Tomoimage was taken after rectal balloon inflated with 60 cc of air for prostate gland immobilization for daily treatment just before treatment and it was used routinely in each case. The intrarectal balloon was inserted to a depth of 6 cm from the anal verge. MVCT image was taken with 5 mm slice thickness after the intrarectal balloon in place and inflated. For this study, lead balls are used to guide the registration between the MVCT and CT simulation images. There are three image fusion methods in the tomotherapy, bone technique, bone/tissue technique, and full image technique. We used all this 3 methods to analysis the setup errors. Initially, image fusions were based on the visual alignment of lead ball, CT anatomy and CT simulation contours and then the radiation therapist registered the MVCT images with the CT simulation images based on the bone based, rectal balloon based and GTV based respectively and registered image was compared with each others. The average and standard deviation of each X, Y, Z and rotation from the initial planning center was calculated for each patient. The image fusions were based on the visual alignment of lead ball, CT anatomy and CT simulation contours. Results: There was a significant difference in the mean variations of the rectal balloon among the methods. Statistical results based on the bone fusion shows that maximum x-direction shift was 8 mm and 4.2 mm to the y-direction. It was statistically significant (P=<0.0001) in balloon based fusion, maximum X and Y shift was 6 mm, 16mm respectively. One patient's result was more than 16 mm shift and that was derived from the rectal expansions due to the bowl gas and stool. GTV based fusion results ranging from 2.7 to 6.6 mm to the x-direction and 4.3$\sim$7.8 mm to the y-direction respectively. We have checked rotational error in this study but there are no significant differences among fusion methods and the result was 0.37$\pm$0.36 in bone based fusion and 0.34$\pm$0.38 in GTV based fusion.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.328-333
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• 2002

Purpose : To analyze the treatment results of concurrent chemoradiation with oral 5-FU plus Gemcitabine or Paclitaxel for unresectable pancreatic cancer. Materials & Methods : The patients, who were diagnosed by imaging modalities or by explo-laparotomy, were treated with concurrent chemoradiation. Radiotherapy was delivered to primary tumor and regional lymph nodes, and the total dose was 45 Gy. Patients received Gemcitabine $1,000\;mg/m^2$ or Paclitaxel $50\;mg/m^2$ weekly and oral 5-FU daily The total number of cycles of chemotherapy ranged from 1 to 39 (median, 11 cycles). The follow-up period ranged from 6 to 36 months, Survival was analyzed using the Kaplan-Meier method. Results : Fifty-four patients between Jan. 1999 to Nov. 2001 were included in this study. Forty-two patients who completed the planned treatment were included in this analysis. The patients' age ranged from 37 to 73 years (median, 50 years) and the male to female ratio was 30:12. Treatment was interrupted for 12 patients due to: disease progression for 6 $(50\%)$, poor performance status for 4 $(33.3\%)$, intercurrent disease for 1 $(8.3\%)$, and refusal for 1 $(8.3\%)$. Response evaluation was possible for 40 patients. One patient gained complete remission and 24 patients gained partial remission, hence the response rate was $59\%$. The survival rates were $46.7\%\;and\;17.0\%$ at 1 year and 2 years, respectively with a median survival time of 12 months. Patients treated with Paclitaxel showed superior outcomes compared to those patients treated with Gemcitabine, in terms of both response rate and survival rate although this difference was not statistically significant. Grade III or IV hematologic toxicity was shown in 8 patients $(19\%)$, while grade III or IV non-hematologic toxicity was shown in 5 patients $(12\%)$. Conclusion : Concurrent chemoradiation with oral 5-FU and Gemcitabine or Paclitaxel improves both the response rate and survival rate in patients with unresectable pancreatic cancer. A prospective study should be investigated in order to improve both the patient selection and the treatment outcome as well as to reduce the toxicity.

• Radiation Oncology Journal
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• v.25 no.2
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• pp.70-78
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• 2007

[ $\underline{Purpose}$ ]: This study analyzed the tumor response, overall survival, progression free survival and related prognostic factors in patients with muscle invasive bladder cancer subjected to bladder preserving treatment. $\underline{Materials\;and\;Methods}$: Between August 1995 and June 2004, 37 patients with muscle invasive (transitional cell carcinoma, clinically stage T2-4) bladder cancer were enrolled for the treatment protocol of bladder preservation. There were 33 males and 4 females, and the median age was 67 years (range $38{\sim}86\;years$). Transurethral resection of the bladder (TURB) was performed in 17 patients who underwent complete resection. The median radiation dose administered was 64.8 Gy (range $55.8{\sim}67\;Gy$). The survival rate was calculated by the Kaplan-Meier method. $\underline{Results}$: An evaluation of the response rate was determined by abdomen-pelvic CT and cystoscopy at three months after radiotherapy. A complete response was seen in 17 patients (46%). The survival rate at three years was 54.7%, with 54 months of median survival (range $3{\sim}91$ months). During the study, 17 patients died and 13 patients had died from bladder cancer. The progression free survival rate at three years was 37.2%. There were 24 patients (64.9%) who had disease recurrence: 16 patients (43.2%) had local recurrence, 6 patients (16.2%) had a distant recurrence, and 2 patients (5.4%) had both a local and distant recurrence. The survival rate (p=0.0009) and progression free survival rates (p=0.001) were statistically significant when compared to the response rate after radiotherapy. $\underline{Conclusion}$: The availability of complete TURB and appropriate chemoradiotherapy were important predictors for bladder preservation and survival.

• Tuberculosis and Respiratory Diseases
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• v.57 no.3
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• pp.257-264
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• 2004

Background : There are many combinations of treatment for locally advanced non-small cell lung cancer (NSCLC). Recent studies have showed the efficacy of concurrent chemoradiotherapy (CCRT) in NSCLC. At present, however, there is no consensus about the optimal dosages and timing of radiation and chemotherapeutic agents. The aims of study were to determine the feasibility, toxicity, response rate, and survival rate in locally advanced NSCLC patients treated with doxetaxel and cisplatin based CCRT. Method : Sixteen patients with unresectable stage III NSCLC were evaluated from May 2000 until September 2001. Induction chemoradiotherapy consisted of 3 cycles of docetaxel (75 $mg/m^2/IV$ on day 1) and cisplatin (60 $mg/m^2/IV$ on day 1) chemotherapy every 3 weeks and concomitant hyperfractionated chest irradiation (1.15 Gy/BID, total dose of 69 Gy) in 6 weeks. Patient who had complete or partial response, and stable disease were applied consolidation chemotherapy of docetaxel and cisplatin. Results : All patients showed response to CCRT. Four patients achieved complete response (25%), partial responses in 12 patients (75%). The major common toxicities were grade III or more of neutropenia (87.3%), grade III esophagitis (68.8%), pneumonia (18.8%) and grade III radiation pneumonitis (12.5%). Thirteen patients were ceased during follow-up period. Median survival time was 19.9 months (95% CI; 4.3-39.7 months). The survival rates in one, two, and three years are 68.7%, 43.7%, and 29.1%, respectively. Local recurrence was found in 11 patients (66.8%), bone metastasis in 2, and brain metastasis in 1 patient. Conclusion : The response rate and survival time of CCRT with docetaxel/cisplatin in locally advanced NSCLC were encouraging, but treatment related toxicities were high. Further modification of therapy seems to be warranted.

• Radiation Oncology Journal
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• v.15 no.1
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• pp.27-36
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• 1997

Purpose : This study was tried to evaluate the Potential benefits of concurrent chemoradiation therapy (low dose daily cisplatin combined with split course radiation therapy) compared with conventional radiation therapy alone in stage III non-small cell lung cancer. The end points of analyses were response rate. overall survival, survival without locoregional failure, survival without distant metastasis, prognostic factors affecting survival and treatment related toxicities. Materials and Methods : Between April 1992 and March 1994, 32 patients who had stage III non-small cell lung cancer were treated with concurrent chemoradiation therapy. Radiation therapy for 2 weeks (300 cGy given 10 times up to 3000 cGy) followed by a 3 weeks rest period and then radiation therapy for 2 more weeks (250 cGy given 10 times up to 2500 cGy) was combined with $6mg/m^2$ of cisplatin. Follow-up period ranged from 13 months to 48 months with median of 24 months. Historical control group consisted of 32 patients who had stage III non-small cell lung cancer were received conventionally fractionated (daily 170-200 cGy) radiation therapy alone. Total radiation dose ranged from 5580 cGy to 7000 cGy with median of 5940 cGy. Follow-up Period ranged from 36 months to 105 months with median of 62 months. Result : Complete reponse rate was higher in chemoradiation therapy (CRT) group than radiation therapy (RT) group (18.8% vs. 6.3%, CRT group showed lower in-field failure rate compared with RT group(25% vs. 47%. The overall survival rate had no significant differences in between CRT group and RT group (17.5% vs. 9.4% at 2 years). The survival without locoregional failure (16.5% vs. 5.3% at 2 years) and survival without distant metastasis (17% vs. 4.6% at 2 years) also had no significant differences. In subgroup analyses for Patients with good performance status (Karnofsky performance scale 80), CRT group showed significantly higher overall survival rate compared with RT group (62.5% vs. 15.6% at 2 years). The prognostic factors affecting survival rate were performance status and pathologic subtype (squamous cell cancer vs. nonsquamous cell cancer) in CRT group. In RT alone group, performance status and stage (IIIa vs IIIb) were identified as a Prognostic factors. RTOG/EORTC grade 2-3 nausea and vomiting(22% vs 6% and bone marrow toxicities (25% vs. 15.6% were significantly higher in CRT group compared with RT alone group. The incidence of RTOG/EORTC grade 3-4 pulmonary toxicity had no significant differences in between CRT group and RT group (16% vs. 6%. The incidence of WHO grade 3-4 pulmonary fibrosis also had no significant differences in both group (38% vs. 25%. In analyses for relationship of field size and Pulmonary toxicity, the Patients who treated with field size beyond 200cm2 had significantly higher rates of pulmonary toxicities. Conclusion : The CRT group showed significantly higher local control rate than RT group. There were no significant differences of survival rate in between two groups. The subgroup of patients who had good performance status showed higher overall survival rate in CRT group than RT group. In spite of higher incidence of acute toxicities with concurrent chemoradiation therapy, the survival gain in subgroup of patients with good performance status were encouraging. CRT group showed higher rate of early death within 1 year, higher 2 year survival rate compared with RT group Therefore, to evaluate the accurate effect on survival of concurrent chemoradiation therapy, systematic follow-up for long term survivors are needed.