• Journal of Radiation Protection and Research
• /
• v.32 no.2
• /
• pp.45-50
• /
• 2007

In this study, uptake rates of internal organs and daily urinary excretion rates were measured to get more reliable estimation results for Korean. Radioactive iodine($^{131}I$) of $100{\mu}Ci$ was administered by ingestion to 28 adult males for the experiment and then the radioactivity in thyroid gland, liver, stomach, small intestine, kidneys, and urine was measured after time intervals of 2, 4, 6 and 24 hours. Uptake rates of each organ and daily urinary excretion rates were calculated on the basis of these experimental results. As a result, uptake rates of 19.70% for thyroid and daily urinary excretion rates of 71.12%, on the average, were indicated. The maximum of uptake rates and daily urinary excretion rates were recorded after 2 hours of administration of $^{131}I$, but those rates were decreased gradually later. It was also found that uptake rates were the highest in stomach, followed by the left kidney, liver, small intestine and right kidney except for thyroid gland. In this experiment, the calculated uptake change rate in thyroid gland after 24 hours of administration of $^{131}I$ was different from that of ICRP-54/67(30%) and ICRP-78(25%). Thus, it is necessary to apply more reliable approach, reflecting the characteristic of Korean physiology and to obtain the basic data of results using this approach for calculation of the internal adsorbed dose. In the future, this approach can be helpful for the internal dose assessment of radiation workers in a nuclear power plant or in a hospital.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.13 no.3
• /
• pp.48-55
• /
• 2009

Purpose: As Korean nuclear law doesn't have any clear guideline about the dose and the external dose rate(uSv/h) requiring hospitalization in radioactive iodine treated patients, the patients are discharged when they meet the guideline of IAEA Basic Safety Standards(BSS). We measured external dose rate(${\mu}Sv/h$) of inpatient underwent 3700MBq (100 mCi) $^{131}I$ radioiodine treatment and considering external dose rate(${\mu}Sv/h$), residual activity(mCi) and excretion rate(%) we found the time for RA to be lowered from 3700MBq (100 mCi) to 1110 MBq (30 mCi) to give reference to set a guideline for discharge. Materials and Methods: Forty-two patients underwent thyroidectomy and scheduled for radioiodine treatment, who received 3700MBq (100 mCi) of $^{131}I$ orally and had no renal disease were examined. After 1, 2, 4, 8, and 20, 24, 40 hours iodine uptake and before/after the urination, the external dose rate(${\mu}Sv/h$) measured using FH40G-L(Thermo Fisher Scientific Inc., MA) at a distance and a height of 1 m for 20 sec on the average. Results and Conclusions: At 20 hours, the external dose rate was decreased to $49{\pm}13\;{\mu}Sv$/h, namely, 78% of administrated radioactivity was excreted and 814 MBq (30 mCi) was residual, and it met the accepted limit for discharge of (IAEA, BSS) under 1110 MBq (30 mCi) (1 m at 66 uSv/h).

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.6
• /
• pp.464-468
• /
• 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 The Korean Society of Clinical Toxicology
• /
• v.9 no.2
• /
• pp.39-48
• /
• 2011

In mass casualty situation due to radiological accidents, it is important to start aggressive management with rapid triage decisions. External contamination needs immediate decontamination and internal contamination should be treated with special expertise and equipment to prevent the rapid uptake of radionuclides by target organs. Acute radiation syndrome shows a sequence of events that varies with the severity of the exposure. More severe exposures generally lead to more rapid onset of symptoms and severe clinical findings. After the massive exposure, various systems of the body reflect their severe damages that can lead to death within hours or up to several months. The disease progression has classically been divided into four stages: prodromal, latent, manifest illness, and recovery or death. Three characteristic clusters of symptoms including the hematopoietic syndrome, the gastrointestinal syndrome and the cerebrovascular syndrome are all associated with the acute radiation syndrome. The standard medical management of the patients with a potentially survivable radiation exposure includes good medical, surgical and supportive measures. Specific treatment with cytokines and bone marrow transplantation should be considered. The management of internal contamination is much the same as the treatment of poisoning. The standard decontamination should be applied to reduce uptake, and the chelating agents can be administered to enhance the clearance of radioisotopes. Radioactive iodine ($^{131}I$) as one of the nuclear fission products can increase the incidence of thyroid cancer in children. Potential benefit of potassium iodide prophylaxis is greater especially in neonates, infants and small children.

• Korean Journal of Head & Neck Oncology
• /
• v.12 no.2
• /
• pp.235-240
• /
• 1996

Brain metastasis is extremely rare in thyroid papillary carcinoma which has an indolent clinical course and results in good prognosis. A 24-year-old man presenting with seizure attack is described. He had been treated under the diagnosis of thyroid papillary carcinoma with total thyroidectomy, postoperative internal radiation with radioactive iodine, and thyroid hormone replacement. Although $^{99m}$Tc brain spect and $^{131}$I whole body scan did not revealed any significant lesion, brain CT and MRI showed lcm sized mass in frontal lobe. Stereotactic craniotomy and removal of the tumor, which was histologically proven metastatic lesion from thyroid papillary carcinoma, was done with satisfactory improvement.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.2 no.3
• /
• pp.181-188
• /
• 2004

The contaminative influence of beef due to the inhalation of air and the ingestion of soil of livestock, both of which are dealt with as minor contaminative pathways in most radioecological models but may not be neglected, was comprehensively investigated with the improvement of the Korean food chain model DYNACON. As the results, it was found that both pathways can not be neglected at all in the contamination of beef in the case of an accidental release during the non-grazing period of livestock. The ingestion of soil was more influential in the contamination of beef than the inhalation of air over most time following an release. If precipitation is encountered during an accidental release, contaminative influence due to the ingestion of soil was far greater compared with the cases of no precipitation. This fact was more distinct for a long-lived radionuclide $^{l37}Cs$ than a short-lived radionuclide $^{131}I$ (elemental iodine). Compared with the results for milk performed prior to this study, the contaminative pathways due to the inhalation of air and the ingestion of soil were more important in beef because of longer biological half-lives. On the other hand, in the case of an accidental release during the grazing period of livestock, radioactive contamination due to the ingestion of pasture was dominant irrespective of the existence of precipitation during an accidental release. It means that contaminative influence due to the inhalation of air and the ingestion of soil is negligible, like the cases of milk.

• Journal of Radiation Protection and Research
• /
• v.44 no.3
• /
• pp.118-126
• /
• 2019

Background: Government conducts environmental radioactivity surveillance for verification purpose around nuclear facilities based on the Nuclear Safety Law and issues a surveillance report every year. This study aims to evaluate the short and the long-term fluctuation of radionuclides detected above MDC and their origins using concentration ratios between these radionuclides. Materials and Methods: Sample media for verification surveillance are air, rainwater, groundwater, soil, and milk for terrestrial samples, and seawater, marine sediment, fish, and seaweed for marine samples. Gamma-emitting radionuclides including $^{137}Cs$, $^{90}Sr$, Pu, $^3H$, and $^{14}C$ are evaluated in these samples. Results and Discussion: According to the result of the environmental radioactivity verification surveillance in the vicinity of nuclear power facilities in 2017, the anthropogenic radionuclides were not detected in most of the environmental samples except for the detection of a trace level of $^{137}Cs$, $^{90}Sr$, Pu, and $^{131}I$ in some samples. Radioactivity concentration ratios between the anthropogenic radionuclides ($^{137}Cs/^{90}Sr$, $^{137}Cs/^{239+240}Pu$, $^{90}Sr/^{239+240}Pu$) were similar to those reported in the environmental samples, which were affected by the global fallout of the past nuclear weapon test, and Pu atomic ratios ($^{240}Pu/^{239}Pu$) in the terrestrial sample and marine sample showed significant differences due to the different input pathway and the Pu source. Radioactive iodine ($^{131}I$) was detected at the range of < $5.6-190mBq{\cdot}kg-fresh^{-1}$ in the gulfweed and sea trumpet collected from the area of Kori and Wolsong intake and discharge. A high level of $^3H$ was observed in the air (Sangbong: $0.688{\pm}0.841Bq{\cdot}m^{-3}$) and the precipitation (Meteorology Post: $199{\pm}126Bq{\cdot}L^{-1}$) samples of the Wolsong nuclear power plant (NPP). $^3H$ concentration in the precipitation and pine needle samples showed typical variation pattern with the distance and the wind direction from the stack due to the gaseous release of $^3H$ in Wolsong NPP. Conclusion: Except for the detection of a trace level of $^{137}Cs$, $^{90}Sr$, Pu, and $^{131}I$ in some samples, anthropogenic radionuclides were below MDC in most of the environmental samples. Overall, no unusual radionuclides and abnormal concentration were detected in the 2017's surveillance result for verification. This research will be available in the assessment of environment around nuclear facilities in the event of radioactive material release.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.12 no.3
• /
• pp.147-156
• /
• 2008

Purpose: All acts which are enforced from the radioactive iodine therapeutic team is a in its own way principle and provision. Therefore unification of all acts can not be appropriately. We will make the standard coherence. Materials & Methods: From 5 November, 2007 to 17 November 2007, we conducted a questionnaire survey of the nuclear medicine manager of 30 hospitals. The contents of a questionnaire is medical treatment section, patient management, prosecuting attorney section, waste management and safety supervision in about the patient and a questionnaire was drawn up in the method which selects an item. Results: 30 hospital agencies are operating purely for I-131 high dose ablation therapy. Diagnostic study and daily schedule had the difference of some. The most of education for the patients took charge of doctor and nurse. The satisfaction of education was evaluated as the high thing. The safety supervision of waste management accomplishment and Safety supervision the patient and the worker observed on the basis of atomic energy law. Conclusion: Specific standards with sufficient amount of information and practical contents should have been presented through the following data. However, it seems to be lacking in many aspects. Nevertheless, respondents rated 70.9%, which is relatively high, on the value of clinical utilization, and I am very thankful for the evaluation. For many years from now, it may seem necessary for a lot of research on the specific matters based on these data to be conducted.

• The Korean Journal of Nuclear Medicine
• /
• v.11 no.1
• /
• pp.39-48
• /
• 1977

Radioactive iodine(RAI), principally $^{131}I$, effectively controls hyperthyroidism in the majority of patients. The subsequent development of hypothyroidism, however, has been of increasing concern since it was first pointed out by Chapman and Maloof in 1955. And the steady increase of late hypothyroidism during the passage of time was known with its relation with dosage of RAI. The authors have investigated the development of hypothyroidism in 935 patients with diffuse toxic goiter(DTG) who were treated with ($RAI^{131}I$) at the Seoul National University Hospital from 1960 to 1977 to reveal its relation with the number of RAI treatments, dosage of RAI, age of patients and exophthalmos with the following results. 1) The incidence of hypothyroidism by year after RAI therapy among 631 patients with DTG who were treated with single RAI regimen was 7.4%(1 year), 11.8%(2 year), 16.2%(3 year), 22.1%(4 year) and 25.5%(5 year), and that among 163 patients given multiple RAI treatments was 8.6%(1 year), 10.4%(2 year), 13.3%(3 year), 29.1%(4 year), and 54.1%(5 year)respectively showing much higher year1y increments from 4 years after RAI treatment. in comparison with the former. 2) Among 550 patients in the lower dose group treated with single RAI regimen less than 5.0mCi ($Mean{\pm}S.D.:\;4.3{\pm}0.6mCi$), the incidence of hypothyroidism by year after RAI treatment was 6.8%(1 year), 11.4%(2 year), 15.4%(3 year), while among 81 patients in the higher dose group given single RAI treatment not less than 5.5 mCi ($Mean{\pm}S.D.:\;6.3{\pm}0.5mCi$) it was 12.0%(1 year), 15.4%(2 year) and 20.4%(3 year) respectively. However, the duration till euthyroid state after RAI therapy in the two groups was $5.1{\pm}3.6$ months and $4.8{\pm}2.8$ months respectively showing no statistically signficant difference (p>0.1). 4) The incidence of hypothyroidism after RAI treatment in patients younger than 30 years of age was 4.3%(1 year) and 7.7%(2 year); in patients from 30 years to 49 years of age, 5.8%(1 year) and 11.1%(2 year); and in those older than 50 years, 11.0%(1 year) and 14.4%(2 year). The data revealed rising incidence of hypothyroidism with increase of patients' age. 4) Among 116 patients with exophthalmos the incidence of hypothyroidism by year after RAI treatment was 7.1%(1 year) and 12.1%(2 year) while that among 184 patients without exophthalmos was 7.3%(1 year) and 12.2%(2 year) respectively. With the above data the authors could conclude that the hypothyroidism in patients with DTG who were treated by RAI developed more frequently than reported by others in Korea till now, and increased with the passage of time, the yearly increments from 4 years after RAI treatment increasing markedly in the multiple dose group, and the incidence could be reduced by decreasing the administered RAI doe not increasing the duration till euthyroid state after RAI therapy.

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