• Journal of radiological science and technology
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• v.39 no.4
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• pp.565-570
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• 2016

Radioactive iodine($^{131}I$) treatment reduces recurrence and increases survival in patients with differentiated thyroid cancer. However, it is important in terms of radiation safety management to measure the radiation dose rate generated from the patient because the radiation emitted from the patient may cause the exposure. Research methods, it measured radiation dose-rate according to the elapsed time from 1 m from the upper abdomen of the patient by intake of radioactive iodine. Directly comparing the changes over time, high dose rate sensitivity and efficiency is statistically significant, and higher chamber than GM counter(p<0.05). Low dose rate sensitivity and efficiency in the chamber had lower levels than gm counter, but not statistically significant(p>0.05). In this study confirmed the characteristics of calibrated ionization chamber and GM counter according to the radiation intensity during high-dose radioactive iodine therapy by measuring the accurate and rapid radiation dose rate to the patient explains, discharged patients will be reduced to worry about radiation hazard of family and others person.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2003.11a
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• pp.579-583
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• 2003

This study was to compare the Intake and Committed Effective Dose(CED) due to inhalation of I-131. The Intake and CED Calculations were based on KIDAC, LUDEP, MONDAL and IMBA computer codes.

• Nuclear Engineering and Technology
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• v.9 no.1
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• pp.1-6
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• 1977

Monoiodobromosulfophthalein-$^{131}$ I (MIBSP-$^{131}$ I), one of the useful radiopharmaceuticals for liver function studies, has been prepared by a simple isotope exchange between the MIBSP and the molecular iodine-$^{131}$ I in phosphate buffer, pH 5.3. The pooled cold MIBSP was prepared by a normal iodination of BSP using iodine monochloride, and separated from the iodination mixture by applying a Sephadex LH-20 chromatography. At 10$0^{\circ}C$, the exchange rate was so fast that the reaction could be terminated in 5 min to show upto 95% yield. The final product could be obtained simply by further heating for about 5 min in a boiling water bath in the presence of a small amount of hydrogen peroxide, and subsequent pH adjustment and membrane filtration.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.3-9
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• 2014

Purpose: Our goals were to evaluate the effect of high dose radioiodine treatment for thyroid cancer by taking in laxatives. Materials and Methods: Twenty patients(M:F=13:7, age $46.3{\pm}8.1\;yrs$) who underwent high dose radioiodine treatment were seperated into Group 1 taking $^{131}I$ 5,500 MBq and Group 2 with the use of laxatives after taking $^{131}I$ 5,500 MBq. The whole body was scanned 16 hours and 40 hours after taking radioactive iodines by using gamma camera, the ROIs were drawn on the gastro-intestinal tract and thigh for calculation of reduction ratio. At particular time during hospitalization, the radioactivity remaining in the body was measured in 1 meter from patient by using survey meter (RadEye-G10, Thermo Fisher Scientific, USA). Schematic presentation of an Origin 8.5.1 software was used for spatial dose rate. Statistical comparison between groups were done using independent samples t-test. P value less than 0.05 was regarded as statistically significant. Results: The reduction ratio in gastro-intestinal 16 hours and 40 hours after taking laxatives is $42.1{\pm}6.3%$ in Group 1 and $72.1{\pm}6.4%$ in Group 2. The spatial dose rate measured when discharging from hospital was $23.8{\pm}6.7{\mu}Sv/h$ in Group 1 and $8.2{\pm}2.4{\mu}Sv/h$ in Group 2. The radioactivity remaining in the body is much decreased at the patient with laxatives(P<0.05). Conclusion: The use in combination with laxatives is helpful for decreasing radioactivity remaining in the body. The radioactive contamination could be decreased at marginal individuals from patients.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.5 no.4
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• pp.267-272
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• 2007

Various kinds of RI wastes are discharged from licensed organizations of radioisotopes les such as hospitals and clinic organizations, educational organizations, research institutions, and public organizations. Radioiodines such as $^{125}I\;and\;^{131}I$ are radioisotopes mainly used in nuclear medicine and industry. A method for the determination of radioiodines in RI wastes has been applied to measure low level activity using acid decomposition method and HPGe gamma ray spectrometer. Prior to analysis of real samples, $^{131}I$ reference solution and 10 g of yellow tissue paper was added to flask in mantle and was heated in 100 mL of 0.4 N $K_2Cr_2O_7$ and 100 mL of 9 M $H_2SO_4$, and then distilled after adding 10 mL of 30% $H_2PO_3$ and 1 mL of 30% $H_2O_2$. The condensed iodine by circulator was extracted into $CCl_4$, then back-extracted into the aqueous phase with 10 mL of 5% $K_2SO_2$ solution. Finally, $^{131}I$ was measured at 364.48 keV using HPGe gamma ray spectrometer after precipitation and filtration. Chemical yield of three steps such as acid decomposition process, chemical separation process, and precipitation and filtration process was more han 94% respectively, MDA(Minimum Detectable Activity) of $^{131}I$ at this analytical condition was 0.6 Bq/g.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.747-752
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• 2014

Iodine-131, an artificial radionuclide, mostly exists as iodide ion ($^{131}I^-$) and iodate ion ($^{131}IO_3{^-}$) in the water, and When a short time contacted, it could not be removed by poly aluminum chloride (PACl) and powdered activated carbon (PAC). Although the removal rate of iodine-131 was not related with turbidity of raw water, it showed linear relationship with contact time with PAC. With the mixture of PACl (24 mg/L or more) and PAC (40 mg/L or more), about 40% of iodine-131 could be removed. Iodine-131 could be removed little by sand filtration, but approximately 100% by granular activated carbon (GAC), both virgin-GAC and spent-GAC. Microfiltration process could remove little iodine-131 while reverse osmosis process could remove about 92% of iodine-131.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.1
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• pp.42-46
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• 2016

The radioactive iodine ($^{131}I$) presents in the environment through the excrete process of nuclear medicine patients. In the detecting of low level of $^{131}I$ in the public water, the counting uncertainty has an effect on the accuracy and reliability of detecting $^{131}I$ radioactivity concentration. In this study, the contribution of sample amount, radioactivity concentration and counting time to the uncertainty was investigated in the case of public water sample. Sampling points are public water and the effluents of a sewage treatment plant at Sapkyocheon stream, Geumgang river. In each point, 1, 10 and 20 L of liquid samples were collected and prepared by evaporation method. The HPGe (High Purity Germanium) detector was used to detect and analyze emitted gamma-ray from samples. The radioactivity concentration of $^{131}I$ were in the range of 0.03 to 1.8 Bq/L. The comparison of the counting uncertainty of the sample amount, 1 L sample is unable to verify the existence of the $^{131}I$ under 0.5 Bq/L radioactivity concentration. Considering the short half-life of $^{131}I$ (8.03 days), a method for measuring 1 L sample was used. However comparing the detecting and preparing time of 1, 10 L respectively, detecting 10 L sample would be an appropriate method to distinguish $^{131}I$ concentration in the public water.

• Journal of radiological science and technology
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• v.33 no.2
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• pp.149-154
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• 2010

Exposed doses to the patient's caregiver and their house due to the 131I from patients discharged from the hospital were measured using OSL dosimeters. Usually, 3.37-5.55 GBq (100-150 mCi) of $^{131}I$ administrated patients are discharged from the hospital after 3 or 4 days of hospitalization in Korea. In addition, after 5 to 8 days, the accumulated doses of the patient's caregiver and house after hospitalization of the patient were measured using OSL dosimeters. The results of the measured average accumulated doses were 0.1 mSv, which is 10% of 1 mSv, the public dose limit in the Korean Atomic Energy Law. And it's standard deviation was 0.087 mSv. Based on the results of this study, we anticipate that we could assure the compliance of the regulation requirement 5 mSv of MEST (Ministry of Education, Science and Technology) Notice No. 2008-45 for the patient's caregiver or family, even if we reduce the 3-4 days of hospitalization to 1-2 days or less.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.2
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• pp.57-61
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• 2014

Purpose Iodine (I-131) is one of the most widely used radioactive isotopes for therapeutic in the field of nuclear medicine. Therapeutic I-131 capsule is made out of lead to shield high energy radiation. Accurate dosimetry is necessarily required to perform safe and effective work for relative workers. The Monte Carlo method is known as a method to predict the absorbed dose distribution most accurately in radiation therapy and many researchers constantly attempt to apply this method to the dose calculation of radiotherapy recently. This paper aims to calculate distance dependent and activity dependent therapeutic I-131 capsule using GEANT4. Materials and Methods Therapeutic capsules was implemented on the basis of the design drawings. The simulated dose was determined by generating of gamma rays of energy to more than 364 keV. The simulated dose from the capsule at the distance of 10 cm and 100 cm was measured and calculated in the model of water phantom. The simulated dose were separately calculated for each position of each detector. Results According to the domestic regulation on radiation safety, the dose at 10 cm and 100 cm away from the surface of therapeutic I-131 capsule should not exceed 2.0 mSv/h and 0.02 mSv/h, respectively. The simulated doses turned out to be less than the limit, satisfying the domestic regulation. Conclusion These simulation results may serve as useful data in the prediction of hands dose absorbed by I-131 capsule handling. GEANT4 is considered that it will be effectively used in order to check the radiation dose.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.6
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• pp.322-326
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• 2006

A low iodine diet (LID) for $1{\sim}2$ weeks is recommended for patients who undergoing radioiodine remnant ablation. However, the LID educations for patients are different among centers because there is no concrete recommendation for protocol of LID. In this investigation, we compared two representative types of LID protocols performed in several centers in Korea using urine iodine to creatinine ratio (urine I/Cr). Methods: From 2006, April to June, patients referred to our center for radioiodine remnant ablation of thyroid cancer from several local hospitals which had different LID protocols were included. We divided into two groups, stringent LID for 1week and less stringent LID for 2 weeks, then measured their urine I/Cr ratio with spot urine when patients were admitted to the hospital. Results: Total 27 patients were included in this investigation (M:F=1:26; 13 in one-week stringent LID; 14 in two-week less stringent LID. Average of urine I/Cr ratio was $127.87{\pm}78.52{\mu}g/g$ in stringent LID for 1 week, and $289.75{\pm}188.24{\mu}g/g$ in less stringent LID for 2 weeks. It was significantly lower in stringent LID for 1 week group (p=0.008). The number of patients whose urine I/Cr ratios were below $100{\mu}g/g$ was 6 of 13 in stringent LID for 1 week group, and 3 of 14 in less stringent LID for 2 weeks group. Conclusion: Stringent LID for 1 week resulted in better urinary I/Cr ratio in our investigation compared with the other protocol. However it still resulted in plenty of inadequate range of I/Cr ratio, so more stringent protocol such as stringent LID for 2 weeks is expected more desirable.