• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.346-355
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• 1997

To evaluate the utility of I-131, T1-201 scintigraphy, and serum thyroglobulin(Tg) in the follow-up of differentiated thyroid cancer, we compared retrospectively the data from 33 patients who underwent total or subtotal thyroidectomy. I-131 scintigraphy was performed after optimal endogenous TSH stimulation ($TSH>50{\mu}U/ml$). Total 41 cases of I-131 and T1-201 scintigraphy pairs were examined. Concomitant serum thyroglobulin levels were measured for 41 pairs of scan. Tg-off levels(that measured after discontinuation of the thyroid hormone) higher than 40ng/m1 were considered positive, and Tg-on levels(that measured during the thyroid hormone replacement) higher than 5ng/ml were considered positive. The concordance rates between I-131 therapeutic scintigraphy and T1-201 scintigraphy was 48% in the 38 case of total scan pairs(59% in the 17 cases of postoperative preablation group, and 38% in the 21 cases of postoperative postablation group). Of 17 studies before the I-131 ablation therapy(preablation group), 7 showed positive I-131 therapeutic scintigraphy despite of negative T1-201 scintigraphy. Among patients with negative I-131 therapeutic scintigraphy, no patients had abnormal T1-201 uptake. However, of 21 studies which were done after radioiodine therapy(postablation group) 6 had abnormal uptake on T1-201 scintigraphy which were not seen on I-131 therapeutic scintigraphy, and Tg-off levels also elevated in this 4 of 6 cases. As a result, I-131 therapeutic scintigraphy showed highest positive rate at postoperative preablation follow-up study in differentiated thyroid cancer patients. T1-201 scintigraphy may be useful in postablation studies, and the use of the combined modalities(T1-201 and Tg levels) provides a higher diagnostic yield.

• Journal of Radiation Protection and Research
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• v.45 no.1
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• pp.2-10
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• 2020

Background: Huge amounts of radionuclides were released into the environment due to the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, which caused not only serious contamination on the ground, but also radiation exposure to the public. One problem that remains in performing the dose estimation is the difficulty of estimating the internal thyroid dose due to the intake of radioiodine (mainly, ¹³¹I) because of limitations to the human data available. Materials and Methods: The relevant papers were collected and reviewed by the authors. The results of thyroid dose estimates from different studies were tabulated for comparison. Results and Discussion: The thyroid dose estimates from the studies varied widely. The dose estimates by the United Nations Scientific Committee on the Effects of Atomic Radiation were higher than the others due to the ingestion dose being based on conservative assumptions. The dose estimates by Japanese experts were mostly below 20-30 mSv. The recent studies suggested that exposure on March 12, 2011 would be crucial for late evacuees from the areas near the FD-NPP because of the possible intake of short-lived radionuclides other than ¹³¹I. Further multilateral studies are vital to reduce uncertainties in the present dose estimations. Conclusion: The estimation of the thyroid doses to Fukushima residents still has many uncertainties. However, it is considered unlikely that the thyroid doses exceeded 50 mSv except in some extreme cases. Further multilateral studies are thus necessary to reduce the uncertainties in the present dose estimations.

• The Korean Journal of Nuclear Medicine
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• v.3 no.1
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• pp.41-49
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• 1969

742 cases of thyroid diseases treated at Radio-isotope Clinic, Seoul National University Hospital since October 1965 through July 1968 were analyzed. The patients were classified according to eye findings, as to Infiltrative, Non-infiltrative and No ophthalmopathy. Correlations between ophthalmological findings and symptoms, BMR values and $^{131}I$ uptake rate as well as response to medical treatment were carefully reviewed. Results obtained were as follows: 1. Among goitrous patients 44.5% with infiltrative ophthalmopathy, 24.1% with non-infiltrative ophthalmopathy totaling 68.6% of patients with one or more eye findings were found. Exophthalmos (44%) and visual disturbances (44%) comprised the highest incidence among eye signs. Most frequent eye symptoms were lid swelling (17.1%). 2. Female patients were predominant(91%). 3. Of cases with hyperthyroidism, after treatment with antithyroid drugs and radio-iodine therapy, general symptoms were improved in over 74%, whereas ophthalmopathy was not changed and in some cases the eye signs were aggravated. This tendency was more apparent in infiltrative ophthalmopathy. 4. Significant correlations between exophthalmos, BMR values and $^{131}I$ uptake rate were found. Among the patients of same degree of exophthalmos, BMR values and $^{131}I$ uptake rate showed the highest in non-infiltrative ophthalmopathy, moderate in infiltrative ophthalmopathy and the lowest in no ophthalmopathy.

• Korean Journal of Head & Neck Oncology
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• v.15 no.2
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• pp.141-148
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• 1999

Objectives: The development of thyroid tumor has a relationship with carcinogen, oncogene and tumor suppressor gene. With aminotriazole, radioactive iodine and nitrosomethylurea as carcinogens in rat, authors investigate the incidence in type of the thyroid tumors, p21 and p53 protein expression pattern by immunohistochemical stain and the relationship between the tumors and p21-p53 protein expressions. Materials and Methods: 80 experimental animals were divided into four groups; group 1(control, no carcinogen, n=20), group 2(oral administration of aminotriazole for 36 weeks, n=20), group 3(intraperitoneal injection of 131I for one time and oral administration of aminotriazole for 36 weeks, n=20), group 4(oral administration of nitrosomethylurea for 3 days and aminotriazole for 36 weeks, n=20). After 40 weeks they were sacrificed with pathologic examination and we performed immunohistochemical staining with pan-ras monoclonal antibody for p21 protein and CMI polyclonal antibody for p53 protein with paraffin-embedded specimens. Results: 1) No tumors were observed in group I, but 38.3% of nodular goiters, 11.7% of adenomas and 50.0% of carcinomas were observed in carcinogen treated groups(group 2, 3, 4). 2) The incidence of nodular goiter, adenoma and carcinoma were 70%, 20% and 10% in group 2, 40%, 15% and 45% in group 3 and 5%, 0% and 95% in group 4. 3) p21 protein was not expressed in normal thyroid tissues but was expressed in 26.1% of nodular goiters, 42.9% of adenomas and 6.7% of carcinomas. On the other hands, p53 protein was not expressed in normal thyroid tissues, nodular goiters, adenomas and in well differentiated thyroid carcinomas by immunohistochemical stain. Conclusion: The authors suggest that aminotrizole, 131I, nitrosomethylurea can be etiologic agents in the development of thyroid tumor and the p21 protein can be expressed in the early stage and in benign condition of thyroid tumor but p53 protein is not expressed in all conditions of development in rats.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3919-3925
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• 2015

When a patient with thyroid cancer is released from isolation after I-131 treatment and return to home using a vehicle, travel time should be controlled to reduce the amount of radiation to accompanying person. As the calculation of appropriate travel time is difficult, there is no patient-specific guideline until now. If we assume that there is no excretion and no physical decay during the relatively short travel time, calculation become quite simple; total radiation dose = dose rate ${\times}$ travel time. Results of this simple calculation and conventional calculation were compared using datum from 120 patients. Travel time calculated by simple method was 56% of conventional method in 0.3 m, 91% in 0.5 m and 96% in 1 m. Simple method was safe. It can be applied easily and also can be applied to the patients with hyperthyroidism treated by I-131.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.879-884
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• 1995

The results of performance assessment analyses have shown that the long-lived radionuclides such as I-129 control the potential individual dose impact to the public. I-129 is difficult-to-measure(DTM) in low-level waste because it is non-gamma emitting radionuclides and exists at extremely low concentrations in radioactive waste generated by nuclear reactors. In this study, computer modeling technique to predict release rate of I-129 is developed to provide another tools far performance assessment of land disposal facilities and characteristics of radwaste. Model suggested in this study will give conservative values of I-129 release rate far determination of radwaste characteristics. More detailed approach is implemented to account for release conditions of fuel source-nuclides. 1-131 concentration measured from reactor coolant and released fraction from tramp fuel have dominant roles in calculating release rate of I-129 with fuel defect conditions.

• The Korean Journal of Nuclear Medicine
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• v.32 no.4
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• pp.374-381
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• 1998

Purpose: I-131 labeled (2'-deoxy-2'-iodo-${\beta}$-D-arabinofuranosyl) adenine (IAD) may be involved in DNA synthesis during active proliferation of tumor cells. We conducted this study to find out the biodistribution of IAD and it's feasibility for scintigraphic tumor imaging. Materials and Methods: Tosyl acetyl-adenosine was dissolved in acetonitrile, and I-131-NaI was added and heated to synthesize IAD. Female Fisher 344 rats innoculated with breast tumor cells were injected with 0.27 MBq of IAD. Rats were sacrificed at 0.5, 1, 2, 4, 24h and the % of injected dose per gram of tissue (%ID/g) was determined. For scintigraphy, rats bearing breast cancer were administered with 1.11 MBq of IAD and imaging was performed after 2 and 24h. Then, rat body was fixed and microtomized slice was placed on radiographic film for autoradiography. Results: %ID/g of tumor was 0.74 (0.5h),0.73 (1h), 0.55 (2h), 0.38 (4h), and 0.05 (24h), respectively. At 1h after injection, %ID/g of tumor was higher than that of heart (0.34), liver (0.42), spleen (0.47), kidney (0.69), muscle (0.14), bone (0.33) and intestine (0.51). However, %ID/g of tumor was lower than blood (1.06), lung (0.77), and thyroid (177.71). At 4h, %ID/g of tumor in comparison with other tissue did not change. Tumor contrast expressed by tumor to blood ratio was 0.69 and tumor to muscle ratio was 5.11 at 1h. However, these ratios did not improve through 24h. On autoradiogram and scintigraphy at 2 and 24 hour, the tumor was well visualized. Conclusion: This results suggest that IAD may have a potential for tumor scintigraphy. However, further work is needed to improve localization in tumor tissue.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1859-1862
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• 2014

Recently, the main therapy of medullary thyroid cancer (MTC) is surgical, but by which way there is a poor prognosis with a mean survival of only 5 years. In some cases, some researchers found that it is the medullary thyroid cancer stem cells (MTCSCs) that cause metastasis and recurrence. This study aimed to eradicate MTCSCs through administration of all-trans-retinoic acid (ATRA). Here we demonstrate that MTCSCs possess stemlike properties in serum-free medium. The ABCG2, OCT4 and sodium iodide symporter (NIS) were changed by ATRA. Additionally, we found that ATRA can increase the expression of NIS in vivo. All the data suggested that ATRA could increase the iodine uptake of MTCSCs through NIS.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.464-468
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• 2008

Purpose: Effective half life of I-131 ($T_{eff}$) in patients with differentiated thyroid cancer treated by I-131 is must-know value for dose calculation and determination of release time from isolation room. There has been no report about $T_{eff}$ in Koreans. Thus, author tried to measure dose rate without radiation exposure to faculty members and calculated $T_{eff}$. Methods: Probe of radiation survey meter was fixed at the wall of isolation room, and body of survey meter was placed outside the room. With this simple arrangement, author could measure radiation frequently without radiation exposure to faculty members in 68 patient (F=55, M=13, age=$47{\pm}13.7$) treated by I-131 ($3.7{\sim}7.4\;GBq$) for differentiated thyroid cancer from Jan 2006 to Dec 2006. From this data, $T_{eff}$, 48 hr retention rate, and the time necessary to whole body retention of I-131 become less than 1.1 GBq were calculated. Serum creatinine levels were measured before and after thyroid hormone withdrawal. Results: $T_{eff}$ was $15.4{\pm}4.3\;hr$ ($9.4{\sim}32.5\;hr$). There was a loose correlation between $T_{eff}$ and serum creatinine concentration (r=0.45). 48hr retention was $4.9{\pm}4.2%$ ($1{\sim}23%$). Time necessary to whole body retention of I-131 become less than 1.1 GBq was calculated as $47.1{\pm}13.2\;hr$ for 9.25 GBq, $42.1{\pm}11.9\;hr$ for 7.4 GBq, $35.7{\pm}10.0\;hr$ for 5.55 GBq, and $26.7{\pm}7.5\;hr$ for 3.7 GBq dose of I-131. Conclusion: Author successfully measured radiation dose rates in isolated patients treated by high dose of I-131 without radiation exposure to the faculty members with simple arrangement of survey meter probe. Using those data, $T_{eff}$ and some other indices were calculated.

• Journal of Radiation Protection and Research
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• v.45 no.3
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• pp.101-107
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• 2020

Background: An important lesson learned from the Fukushima accident is that the transition to the mid- and long-term phases from the emergency-response phase requires less than a year, which is not very long. It is necessary to know how much radioactive material has been deposited in an urban area to establish mid- and long-term countermeasures after a radioactive accident. Therefore, an urban deposition model that can indicate the site-specific characteristics must be developed. Materials and Methods: In this study, the generalized urban deposition velocity and the subsequent variation in radionuclide contamination were estimated based on the characteristics of the Korean urban environment. Furthermore, the application of the obtained generalized deposition velocity in a hypothetical scenario was investigated. Results and Discussion: The generalized deposition velocities of ¹³⁷Cs, ¹⁰⁶Ru, and ¹³¹I for each residence type were obtained using three-dimensional (3D) modeling. For all residence types, the deposition velocities of ¹³¹I are greater than those of ¹⁰⁶Ru and ¹³⁷Cs. In addition, we calculated the generalized deposition velocities for each residential types. Iodine was the most deposited nuclide during initial deposition. However, the concentration of iodine in urban environment drastically decreases owing to its relatively shorter half-life than ¹⁰⁶Ru and ¹³⁷Cs. Furthermore, the amount of radioactive material deposited in nonresidential areas, especially in parks and schools, is more than that deposited in residential areas. Conclusion: In this study, the generalized urban deposition velocities and the subsequent deposition changes were estimated for the Korean urban environment. The 3D modeling was performed for each type of urban residential area, and the average deposition velocity was obtained and applied to a hypothetical accident. Based on the estimated deposition velocities, the decision-making systems can be improved for responding to radioactive contamination in urban areas. Furthermore, this study can be useful to predict the radiological dose in case of large-scale urban contamination and can support decision-making for long-term measurement after nuclear accident.