• 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
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• v.28 no.2
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• pp.200-205
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• 1994

그레이브스 갑상선기능항진증은 자가면역질환의 하나로 방사성 옥소가 간편하고 경제적이며 효과적인 치료법임이 알려져 있는데 방사성 옥소 투여 후 갑상선 조직의 자극 및 파괴에 따라 각종 항원의 노출의 증가와 이에 대한 자가항체의 변동이 예상된다. 저자들은 추정 갑상선 무게를 고려한 6-10 mCi의 방사성 옥소를 투여 받은 그레이브스 갑상선기능항진증 환자 90명을 2년간 추적하여 치료 전 후의 혈청 갑상선자극 면역글로불린(TBIIl)활성도와 thyroglobulin 및 antithyroglobulin antibody의 변화를 관찰하였다. 1) 대상환자 90명의 연령분포는 14-58세(중앙치 30)였으며 여자가 72명(80%)이었다. 2) 평가대상 환자 중 치료 전 TBIIl 활성도가 정상범위였던 경우는 15명(30%)이었고 증가된 경우는 35명(70%)이었다. 치료 전보다 치료 3개월 후에 TBII 활성도가 더 증가된 경우는 31명(62% )이었다. 3) TBII 활성도가 치료 전에 증가하였거나, 치료 전에 정상범위였다가 치료 3개월 후에 증가한 환자의 TBII 활성도의 동태는 치료 3개월 후에 가장 높았고 그 후 점차 감소하였다. 이들의 TBIIl 활성도가 15%이내로 정상화된 정도는 치료 후 6개월에 40%, 12개월에 82%였다. 4) 치료 전 antithyroglobulin antibody가 양성인 경우 80%에서 3개월 후에도 혈청 thyroglobulin의 동태는 치료 3개월 후에 높았다가 증가가 없었으며 치료 전 antithyroglobulin antibody가 음성인 경우 60%에서 치료 3개월 후에 혈청 thyroglobulin의 증가가 있었다. 5) antithyroglobulin antibody가 음성인 경우의 혈청 thyroglobulin의 동태는 치료 3개월 후에 높았다가 점차 감소하는 경향을 보였으며 antithyroglobulin antibody가 양성인 경우의 혈청 thyroglobulin의 동태는 치료 후 시간이 지남에 따라 점차 감소하였다. 6) 치료 전 antithyroglobulin antibody가 음성인 경우 치료 후 시간 경과에 따라 동시에 측정한 혈청 TBII 활성도와 thyroglobulin 사이에는 통계적으로 유의한 상관관계가 있었다(p<0.01). 한편 치료 전 antithyroglobulin antibody가 양성인 경우 치료 후 시간 경과에 따라 동시에 측정한 혈청 TBII 활성도와 thyroglobulin 사이에는 통계적으로 유의한 상관관계가 없었다(p= 0.16). 이상의 결과로 방사성 옥소를 투여 받은 그레이브스 갑상선기능항진증 환자에서 혈청 TBII 활성도는 항갑상선제를 투여 받은 경우와는 달리 초기에 증가하였다가 시간이 지남에 따라 점차 감소함을 알 수 있었으며 그 감소 정도는 항갑상선제만을 쓴 경우보다 더 빠를 것으로 생각된다. 따라서 혈청 TBII 활성도와 thyroglobulin은 방사성 옥소 치료효과의 관찰에 중요한 역할을 할 것으로 생각되며 특히 antithyroglobulin antibody가 음성인 경우 혈청 thyroglobulin은 혈청 TBII 활성도를 반영할 것으로 사료된다.

• 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.

• 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.

• 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.

• 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.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.49-54
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• 2017

Purpose The high-dose administration of I-131 has been standing for the basic therapy method of thyroid cancer. In korea, it is not necessary for patients to be hospitalized if the administration dose are under 1.2 GBq. However, if the dose are over 1.2 GBq, the patients should be stay in special ward with radiation shield. In such cases, the radioactivity level upon release should be under a dose of $70{\mu}Sv/hr$ at a distance of approx. 1m. This regulation bring the patients to stay for about 2 to 3 days in ward before the release. Materials and Methods Using the inpatients' release data of severance hospital, an inpatient-days were retrospectively calculated and compared with practical data and estimate the inpatient-days with the conditions of korea ($70{\mu}Sv/hr$), Japan ($30{\mu}Sv/hr$), germany ($3.5{\mu}Sv/hr$ at a distance of approx. 2 m), and other european countries. Results When a effective half-life of 15.4 was used, the expected inpatient-days were calculated as 2.15 days in the condition of Japanese regulation and 1.37 days in the condition of korean regulation. The practical inpatient-days of patients in Severance hospital were 1.32 days. Conclusion As ICRP 94 has been mentioned that the release of patients administrated with I-131 for the therapy should be carefully considered because each patients has different thyroid uptake rate and their conditions with family members after the release from the ward. Nonetheless, efforts to bring more aquate data which is for getting closer to the practical data should be continuously studied.

• The Korean Journal of Nuclear Medicine
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• v.4 no.2
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• pp.29-39
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• 1970

A summary of the clinical data of the $^{131}I$-thyroid function tests and the therapeutic results of $^{131}I$ among the 2,658 patients of various thyroid diseases treated over the past 10 years from May 1960 to Oct. 1969 at the Radioisotope Clinic and Laboratory, SNUH were presented and dscussed. 1. The patients examined consisted of: 929 cases (34.9%) of diffuse toxic goiter, 762 cases (28.7%) of diffuse nontoxic goiter, 699 cases (26.3%) of nodular nontoxic goiter, 58 cases (2.2%) of nodular toxic goiter and 210. cases (7.9%) of hypothyroidism. 2. There were 300 (11.4%) male and 2358 (88.6%) female, showing a ratio of 1:8. 3. The majority of patients (79.1%) were in the 3rd-5th decades of their lives. 4. The normal ranges, diagonstic values of $^{131}I$ uptake test, 48 hrs, serum activity, BMR and main subjective symptoms of various thyroid diseases were discussed. 5. In the 579 patients among 867 cases with hyperthyroidism treated with $^{131}I$, 47.8% were confirmed to be cured completely after single therapeutic doses. 6. The complications of $^{131}I$ therapy were discussed and myxedema had developed in 6.75% of our patients. 7. The results of $^{131}I$ thyroid function tests were analysed among the 160 cases of thyroid diseases which were confirmed the diagnosis with histopathological measures.

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