• The Korean Journal of Nuclear Medicine
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• v.1 no.1
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• pp.67-78
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• 1967

Over the past 6 years, from May 1960 to June 1966, 1,716 patients with various diseases of thyroid were examined and thyroid function tests with $^{131}I$ were done. Among them, 545 patients with hyperthyroidism were treated with $^{131}I$. A summary of the clinical data of the $^{131}I$-thyroid function tests and the therapeutic results of $^{131}I$ were presented and discussed. 1. The patients examined consisted of; 596 cases(34.7%) with toxic diffuse goiter, 412 cases(24.0%) with non-toxic nodular goiter, 278 cases(16.2%) with euthyroidism, 236 cases(13.8%) with non-toxic diffuse goiter, 89 cases(5.2%) with hypothyroidism, 53 cases(3.1%) with toxic nodular goiter, 32 cases(1.9%) with thyroiditis and 20 cases(1.2%) with dyshormonogenesis. 2. There were 218(12.7%) male patients and 1,498(87.3%) female patients, showing a ratio of 1:6.9. female predominantly. 3. The majority of patients(79.6%) were in the 3rd through 5th decades of their lives showing the peak in the 4th decades(35.9%). 4. The diagnostic values and normal ranges of $^{131}I$ uptake test, 48 hour serum activity, $T_3$ red blood cell uptake and $PB^{131}I$ conversion ratio were discussed. 5. An attention was given to dyshormonogenesis, a qualitative hypothyroidism, due to its characteristic findings of clinical and $^{131}I$ thyroid function tests, and its pathogenesis was briefly reviewed. 6. Among 545 patients with hyperthyroidism treated with $^{131}I$, 68.3% was cured after single. therapeutic dose and another 24.0% was cured after second dose. 7. The complications of $^{131}I$ therapy were discussed in some details and myxedema had developed. in 3.9% of our cases. No thyroid cancer was found after $^{131}I$ therapy.

• 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).

• 대한핵의학회:학술대회논문집
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• 1973.11a
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• pp.53.2-53.2
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• 1973

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1355-1363
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• 2018

Many radionuclides exist in normal environment and artificial radionuclides also can be detected. The radionuclides ($^{131}I$) are widely used for labeling compounds and radiation therapy. In Korea, the radionuclide ($^{131}I$) is produced at the Radioisotope Production Facility (RIPF) at the Korea Atomic Energy Research Institute in Daejeon. The residents around the RIPF assume that $^{131}I$ detected in environmental samples is produced from RIPF. To ensure the safety of the residents, the radioactive concentration of $^{131}I$ near the RIPF was investigated by monitoring environmental samples along the Gap River. The selected geographical places are near the nuclear installation, another possible location for $^{131}I$ detection, and downstream of the Gap River. The first selected places are the "front gate of KAERI", and the "Donghwa bridge". The second selected place is the sewage treatment plant. Therefore, the Wonchon bridge is selected for the upstream of the plant and the sewage treatment plant is selected for the downstream of the plant. The last selected places are the downstream where the two paths converged, which is Yongshin bridge (in front of the cogeneration plant). In these places, environmental samples, including sediment, fish, surface water, and aquatic plants, were collected. In this study, the radioactive iodine ($^{131}I$) detection along the Gap River will be investigated.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.272-273
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• 2004

We experienced a case with meningioma showing false positive I-131 uptake. A 55-years old female patient underwent high dose (150 mCi) radioactive iodine therapy to ablate remnant tissue after total thyroidectomy for papillary thyroid cancer. in addition to intense tracer uptake in thyroid bed, there was mild but focal abnormal uptake in left frontal lobe of the brain on post-therapy I-131 whole body scan. Subsequent brain MR imaging showed single mass lesion in left frontal lobe and the mass was resected under the impression of brain metastasis of thyroid carcinoma. Pathologic report confirmed meningioma from the surgical specimen.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.285-293
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• 2000

Purpose: A prospective comparison was made between imaging with Tc-99m pertechnetate (Tc-99m) and Ioine-131 (I-131) for the detection of residual and metastatic tissue after total thyroidectomy in patients with well-differentiated thyroid carcinoma. Materials and Methods: Initially our patients had imaging with Tc-99m, followed by I-131 within 3 days. The study included 21 patients who had ablation with high dose of I-131 ranging from 100 mCi to 150 mCi. Planar and pinhole images were acquired for both Tc-99m and I-131. Diagnostic images of Tc-99m and I-131 were compared with post-therapy images. Degree of uptake on Tc-99m and I-131 images was scored by four point scale and compared. Results: The results of the Tc-99m study were: 16 of 19 studies (84%) were positive on simple planar images, but 19 of 20 studies (95%) were positive on pinhole images. Conventional I-131 diagnostic imaging on the other hand showed that all studies (100%) were positive on both planar and pinhole images. There was a significant difference in degree of uptake between Tc-99m and I-131 planar images (p<0.05). Only one case of Tc-99m scintigraphy was negative on both planar and pinhole studies (false negative). There was no distant metastasis on the therapeutic I-131 images. Conclusion: Tc-99m scan using pinhole in certain clinical situations is an alternative to the I-131 scan in detecting thyroid or lymph node metastasis prior to the first ablative treatment after thyroidectomy for well-differentiated thyroid carcinoma.

• The Korean Journal of Nuclear Medicine
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• v.33 no.4
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• pp.422-429
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• 1999

Purpose: The measurement of radiation absorbed dose is useful to predict the response after I-131 labeled metaiodobenzylguanidine (MIBG) therapy and determine therapy dose in patients with unresectable or malignant pheochromocytoma. We estimated the absorbed dose in tumor tissue after high dose I-131 MIBG in a patient with pheochromocytoma using a gamma camera and Medical Internal Radiation Dose (MIRD) formula. Materials and Methods: A 64-year old female patient with pheochromocytoma who had multiple metastases of mediastinum, right kidney and periaortic lymph nodes, received 74 GBq (200 mCi) of I-131 MIBG. We obtained anterior and posterior images at 0.5, 16, 24, 64 and 145 hours after treatment. Two standard sources of 37 and 74 MBq of I-131 were imaged simultaneously. Cummulated I-131 MIBG uptake in tumor tissue was calculated after the correction of background activity, attenuation, system sensitivity and count loss at a high count rate. Results: The calculated absorbed radiation dose was 32-63 Gy/ 74 GBq, which was lower than the known dose for tumor remission (150-200 Gy). follow-up studies at 1 month showed minimally reduced tumor size on computed tomography, and mildly reduced I-131 MIBG uptake. Conclusion: We estimated radiation absorbed dose after therapeutic I-131 MIBG using a gamma camera and MIRD formula, which can be peformed in a clinical nuclear medicine laboratory. Our results suggest that the measurement of radiation absorbed dose in I-131 MIBG therapy is feasible as a routine clinical practice that can guide further treatment plan. The accuracy of dose measurement and correlation with clinical outcome should be evaluated further.

• 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.

• 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.

• The Korean Journal of Nuclear Medicine
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• v.32 no.5
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• pp.436-442
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• 1998

Radioactive iodine treatment has been widely used for nearly 50 years in the treatment of thyroid cancer to ablate residual thyroid tissue after thyroidectomy and to treat metastatic disease. Leukemia is a rare complication associated with the radioactive iodine therapy. The occurrence of leukemia is known to be related to the cumulative dosage of I-131 more than 37 GBq (1 Ci) and also associated with the intervals of less than 12 months between the repeated doses. We report a case of a 52 year-old female patient with papillary cancer of thyroid who developed acute myelogenous leukemia after the total 20.4 GBq (550 mCi) of I-131 therapy over 3.2 years and palliative radiation therapy (3000 cGy) due to multiple bone metastasis of papillary cancer.