• Nuclear Engineering and Technology
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• v.13 no.3
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• pp.145-152
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• 1981

Even though a lately reported method of high temperature exchange labelling of o-iodo-hippuric acid (Hippuran) in the absence of oxidizing agent was considered to be an attractive one, the exchange mechanism was somewhat unclear. In this study iodine isotope exchanges between o-iodohippuric acid (OIH) and radioiodide ($^{125}$ $I^{ }$) or between OIH and molecular radioiodine ($^{125}$ $I_2$) were carried out at two different temperatures. Rate constants and activation parameters were measured by applying a radio-paper chromatography technique. Since o-iodobenzoic acid is known as a by-product in the exchange labelling of OIH, data were also obtained for the OIB-iodide systems for comparison. The rate constant was increased in the order of OIB...$^{125}$ $I^{[-10]}$ >OIB...$^{125}$ $I_2$>OIH..$^{125}$ $I^{[-10]}$ >OIH...$^{125}$ $I_2$ and the activation parameters for OIH were generally larger than those for OIB :$\Delta$H$\neq$$_{OIH}$>$\Delta$H$\neq$$_{OIB}$, $\Delta$S$\neq$$_{OIH}$>$\Delta$S$\neq$$_{OIB}$. These results suggest that the mechanism of the high temperature exchange is predominantly nucleophilic even though some electrophilic character can also be involved depending upon reaction conditions. Such a fact may well be caused by a feasible formation of hydrogen bonding type transition state due probably to the ortho substituent effect of-CONHC $H_2$COOH. Thus, the high temperature exchange method is estimated to be quite effective for labelling Hippuran especially at a small research center where reducing agent-free $^{131}$ I is unavailable.ailable..

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.294-300
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• 2009

Purpose: The purpose of this study was to evaluate if short-term serum thyroglobulin (Tg) elevation after radioiodine administration can predict successful radioiodine remnant ablation (RRA) and whether comparable RRA effectiveness is exhibited between a group administered with recombinant human thyrotropin (rhTSH) and a group experiencing thyroid hormone withdrawal (THW), in preparation for RRA. Materials and Methods: A retrospective chart review was performed on 39 patients in the rhTSH group and 46 patients in the THW group. They were treated for differentiated thyroid carcinoma by total or near total thyroidectomy, and referred for RRA between 2003 and 2006 (the rhTSH group) and between January and June of 2006 (the THW group). They were assessed for serum Tg levels just before I-131 administration (TgD0), reassessed 9 days later (TgD9), and again 6-12 months later. Results: RRA was successful in 64 (37 from the THW group and 27 from the rhTSH group) of the total 85 patients. The success rates of RRA had no statistically significant differences between the two groups. In both groups, TgD9/TgD0 values were significantly higher in the RRA success group (the rhTSH group; P = 0.03, the THW group; P = 0.04). By combining cutoff values of TgD0 and TgD9/TgD0, the successful RRA value was determined to be 96.7% (29/30) with TgD0$\leq$5.28 ng/mL and TgD9/TgD0>4.37 in both groups (the rhTSH group; 100% (16/16), the THW group; 92.9% (13/14)). Using logistic multivariate analysis, only TgD0 was independently associated with successful RRA. Conclusion: We may predict successful ablation by evaluating short-term serum Tg elevation after I-131 administration for RRA, in both rhTSH and THW patients.

• Asian Oncology Nursing
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• v.12 no.4
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• pp.297-304
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• 2012

Purpose: This study was to identify the symptom severity, interference and their psychological predictors in thyroid cancer patients hospitalized for radioactive iodine administration. Methods: One hundred seventy-seven thyroid cancer patients admitted to the isolation room for Iodine ($I^{131}$) therapy were recruited. Subjects were asked to complete the questionnaire on core symptoms, thyroid cancer symptoms, interference, depression and state anxiety in the evening after receiving radioactive iodine therapy. Data was analyzed using frequency, percentage, mean, Pearson's correlation, and multiple regression with SPSS vs. 19. Results: Lack of appetite, drowsiness, sleep disturbance, fatigue, and nausea were the 5 most core symptoms. More than 20% of patients experienced moderate to severe thyroid cancer symptoms including feeling cold, hoarseness, swallowing difficulty, and feeling hot. More than 30% of subjects experienced moderate to severe interferences in mood, general activity, and 22% in walking. Depression and state anxiety were identified as predictors of core symptoms, thyroid symptom severity and interference. Conclusion: Nursing interventions to reduce the symptom severity and interference need to be developed by considering thyroid cancer patients' depression and anxiety when hospitalized in the isolation room for radioactive iodine administration.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.174-178
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• 2001

Background and Objective: Percutaneous ethanol injection therapy has been used in the treatment of the benign thyroid diseases. Although the reported side-effects of the therapy was mild and transient, some side-effects including local or radiating pain are troublesome to the patients. Radioactive iodine-131($Ra-^{131}I$) also has been effectively and safely used for management of the benign thyroid diseases. So we developed the percutaneous intranodular injection therapy of $Ra-^{131}I$ as an alternative of percutaneous ethanol injection therapy. Materials and Methods: From December 1998 to October 1999, we treated 29 outpatients (25 women and 4 men, mean age: $47{\pm}12$ years). Inclusion criteria were follows; age >30 years, cytologically benign, with normal thyroid function, cold nodule on thyroid scintigram, solid or mixed natured nodules in sonographical evaluation. Nodular volume was estimated by sonography according to the ellipsoid formula. $Ra-^{131}I$(0.1mCi/ml) was administered in a single dose injection. Follow-up studies every 3 months consisted of full history, thyroid function test, and sonography. We determined the therapeutic response is effective if the volume reduction of the nodule occurred above 30%. Results: After at least 3 months follow-up, 11 patients showed effective response, 12 patients showed minimal or unchanged response and 6 patients showed progression. Although side-effects such as injection pain, febrile reaction, and hormonal changes were absent, an infectious complication in injection site was developed from 1 case. Conclusion: Although we need a more prolonged follow-up to evaluate the delayed sequelae, we can suggest that percutaneous intranodular injection therapy of $Ra-^{131}I$ may be an attractive non-surgical treatment in selected cases of benign thyroid nodules.

• Journal of radiological science and technology
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• v.45 no.4
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• pp.347-353
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• 2022

In this study, the radiation dose rate was measured by time and distance and evaluated whether radiation dose rate was suitable for domestic and international discharge criteria. In addition, the radiation dose emitted from the patient was measured with a glass dosimeter to evaluate the exposure dose if the caregiver stays in the isolated ward by placing a humanoid phantom instead of the caregiver at a distance of 1 m from the patient, on the second day of treatment. After 23 hours of isolation, the radiation dose rates at a distance of 1 m were 20.54 ± 6.21 µSv/h at 2.96 GBq administration and 27.94 ± 12.33 µSv/h at 3.70 GBq administration. The radiation dose rates at a distance of 1 m were 25.90 ± 2.21 µSv/h when 2.96 GBq was administered and 34.22 ± 10.06 µSv/h when 3.70 GBq was administered after 18 hours of isolation. However, if the isolation period is short may cause unnecessary radiation exposure to the third person. The reading of the attached dosimeter from the morning of the second day of treatment until removal was 0.01 to 0.95 mSv, which is a surface dose determined by the International Commission on Radiation Units and Measurements. And the depth dose was 0.01 to 0.99 mSv. On the second day of treatment, even if the patient caregivers stayed in the isolation ward, the exposure dose of the patient family did not exceed the effective dose limit of 5 mSv recommended by the ICRP and NCRP.

• Journal of Radiation Protection and Research
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• v.30 no.3
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• pp.99-105
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• 2005

A model for evaluating radioactive contamination in the urban environment, named METRO-K, was developed as a basic step for accident consequence analysis in case of an accidental release. The three kind of radionuclides $(^{137}Cs,\;^{106}Ru,\;^{131}I)$ and the different chemical forms of iodine (particulate, organic and elemental forms) are considered in the model. The radioactive concentrations are evaluated for the five types of surface (roof, paved road, wall, lawn/soil, tree) as a function of time. Using the model, the contaminative impacts of the surfaces were intensively investigated with respect to with and without precipitation during the measurement periods of radionuclides in air. In addition, a practical application study was conducted using $^{137}Cs$ concentration in air and precipitation measured in an European country at the Chernobyl accident. As a result precipitation was an influential factor in surface contamination. The degree of contamination was strongly dependent on the types of radionuclide and surface. Precipitation was more influential in contamination of $^{137}Cs$ than that of $^{131}I$ (elemental form).

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.597-603
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• 2017

High-dose $^{131}I$ therapy has been generally carried out to remove remaining thyroid tissue or to cure metastasize lesion of patients who received full thyroidectomy due to differentiated thyroid cancers. In case high-dose $^{131}I$ therapy is carried out for a patient, the patient should be hospitalized being isolated for a certain period in order to restrict the amount of exposure to radiation of people at large from the patient within the limit of a level of radiation. Effective half-life is an important value to calculate how family members are exposed to radiation from a patient or to decide the period of isolation of the patient from the family members. Therefore, in this study we calculated the effective decay constant, effective half-life and period of isolation of high-dose $^{131}I$ therapy patient using NM670 SPECT/CT. As a result of carrying out this study, the effective half-life of high-dose $^{131}I$ therapy patients was derived and the time to reach the discharge level of 1.2 GBq was confirmed. When they were compared with each other in each of curative doses, the effective half-life did not have significant difference, but the time when the level of radiation remaining in the interior of the body to reach the criteria of isolation and discharge showed significant difference and it could be confirmed that the higher the curative dose the longer the period of isolation becomes. When the effective half-lives in each type of preparation were compared with each other, they did not show significant difference. However, When the times to reach the level of radiation that is the criteria of isolation and discharge in each type of preparations, they showed significant difference. The cause of the shortening of the isolation period for rhTSH patients group is decided to be low curative dose. Accordingly, if the current national health insurance (the insurance is applied to using of rhTSH in 3.7 GBq or lower) is maintained, while discerning them in each of types of preparation, we would be able to discharge patients at the time earlier than the current period of isolation (2 nights and 3 days).

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.12-17
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• 2012

Purpose : The patient's clothes and sheet after radioiodine therapy must be disposed of by related regulation. That must be disposed of as radioactive wastes, but that is reusing after radioactivity decay by keeping for the certain period of time. In general, The minimum storage period calculate by standard of take radioactive substance out of radiation controlled area based on measured surface contamination level. But the measurements of surface contamination level are able to differ by measurement method. In this paper, I wish to calculate the minimum storage period of patient's clothes and sheet after radioiodine therapy by measure nuclide concentration offered by the regulation on self-disposal of radioactive wastes. Materials and Methods : The whole area of patient's clothes and sheet measured 31 patients(male:9 patients, female:22 patients), who had radioiodine therapy(3.7 GBq:13 patients, 5.55 GBq:16 patients, 7.4 GBq:2 patients) from july 2011 to march 2012. The minimum storage period is calculated by the regulation on self-disposal of radioactive waste(100 Bq/g) and standard of take radioactive substance out of radiation controlled area(4 kBq/m2) Results : The minimum storage period of pillow sheet, upper uniform, lower uniform by standard of take radioactive substance out of radiation controlled area were each 4.6 days, 63days, 78 days. The minimum storage period of pillow sheet, upper uniform, lower uniform by the regulation on self-disposal of radioactive waste were each 18.1 days, 43 days, 62 days. Conclusion : We can verify that patient's clothes and sheet after radioiodine therapy exists a great deal of radioactive contamination. The minimum storage period calculation of patient's clothes and sheet is better suited to applying nuclide concentration offered by the regulation on self-disposal of radioactive waste. I recommend, To keep for at least 2 months of the patient's clothes and sheet contaminated radioactivity, for prevent contamination and unnecessary radiation exposure.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.3
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• pp.223-234
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• 2016

This study aimed to the adsorption-removal of high- radioactive iodide (I) contained in the initially generated high-radioactive seawater waste (HSW), with the use of AgX (Ag-impregnated X zeolite). Adsorption of I by AgX (hereafter denoted as AgX-I adsorption) was increased by increasing the Ag-impregnated concentration in AgX, and its concentration was suitable at about 30 wt%. Because of AgCl precipitation by chloride ions contained in seawater waste, the leaching yields of Ag from AgX (Ag-impregnated concentration : about 30~35 wt%) was less than those in distilled water (< 1 mg/L). AgX-I adsorption was above 99% in the initial iodide concentration ($C_i$) of 0.01~10 mg/L at m/V (ratio of weight of adsorbent to solution volume)=2.5 g/L. This shows that efficient removal of I is possible. AgX-I adsorption was found to be more effective in distilled water than in seawater waste, and the influence of solution temperature was insignificant. Ag-I adsorption was better described by a Freundlich isotherm rather than a Langmuir isotherm. AgX-I adsorption kinetics can be expressed by a pseudo-second order rate equation. The adsorption rate constants ($k_2$) decreased by increasing $C_i$, and conversely increased by increasing the ratio of m/V and the solution temperature. This time, the activation energy of AgX-I adsorption was about 6.3 kJ/mol. This suggests that AgX-I adsorption is dominated by physical adsorption with weaker bonds. The evaluation of thermodynamic parameters (a negative Gibbs free energy and a positive Enthalpy) indicates that AgX-I adsorption is a spontaneous reaction (forward reaction), and an endothermic reaction indicating that higher temperatures are favored.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.243-250
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• 2018

BACKGROUND: Recently, the use of $^{131}I$ for diagnosis and treatment of thyroid cancer has been increasing, and the radionuclide is continuously released into aquatic ecosystem. This study was carried out to investigate the $^{131}I$ concentrations in mainstreams, tributaries, and sewage wastewater treatment plants (SWTPs) of the Yeongsan River Basin and to identify their origins from the assessment of behaviors in the rivers. METHODS AND RESULTS: The water samples were collected from 19 sites including mainstreams (13), tributaries (4) and SWTPs (2). The $^{131}I$ concentration was measured using a gamma-ray spectrometry with a HPGe detector. The $^{131}I$ in SWTPs was detected mostly in the discharged effluent at the sampling sites. However, from the surface water of the rivers, $^{131}I$ was found only at two sites from each sampling period of the first (MS4 and MS10) and the second half (MS4 and MS7) of the year 2017. The concentrations of $^{131}I$ in the effluent discharged from SWTPs were in the range of 0.0870 to 3.87 Bq/L for SWTP1, and $^{131}I$ in the river revealed that it was not detected in the upper streams of the mainstreams and tributaries, while continuous detection was found in the SWTPs and downstream sites affected by the effluent. However, the concentration of $^{131}I$ decreased downstream, eventually becoming undetectable. Such behavior was closely related to the behavior found in the SWTPs. CONCLUSION: These results indicated that medically-derived $^{131}I$ was discharged to the river via sewage effluent at the SWTPs. It is necessary to evaluate the influence of aquatic ecosystems through continuous monitoring in the future.