• 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
• /
• v.28 no.1
• /
• pp.124-132
• /
• 1994

Radioactive iodine has been widely used in patients with thyroid cancer combined with surgical treatment. However, due to individual variations in absorption and excretion and uptake by tumor tissue of radioactive iodine, there are differences in therapeutic effect and adverse effects even if the same doses are administrated. So this study compared the therapeutic effect and radiation hazard by measuring internal radiation dose. Of total 27 patients with well differentiated thyroid cancer who had been thyroidectomized, we administered radioactive iodine 100 mCi, 150 mCi, 200 mCi. According to BEL DOSIMETRY PROTO-COL, beta and gamma ray dose were estimated from a pelt of the logarithm of the percent of dose per liter of whole blood versus day, and percent dose retained versus day using somilogarithmic paper, respectively. 1) Physical dose to whole blood averaged $56.54{\pm}13.02$ rad in 100 mCi administered group, $76.83{\pm}19.97$ rad in 150 mCi administered group, $95.08{\pm}25.51$ rad in 200 mCi administered group and there has been a significant correlation among the groups. 2) Mean percent dose retained 48 hours later was 26.34%. 3) There was no significant correlation of physical dose between absence and presence of metastasis. 4) 17 of 19 patients who has been followed up with TSH and serum throglobulin, Thallium scan were successfully ablated by radioactive iodine. 5) Leukocyte, lymphocyte, neutrophil, platelet counts all deelined in 4.6 weeks and most of all were restored 3 months later. 6) There was no significant correlation between physical dosimetry and biologic dosimetry. Generally administered doses of radioactive iodine (100-200 mCi) to patients with thyroid cancer postoperatively had developed transient bone marrow suppression and minimal chromosomal aberration, but they were within safety dose to blood (200 rad). And there has been no significant differences in residual dose 48 hours later between Korean and western people.

• The Korean Journal of Nuclear Medicine
• /
• v.31 no.3
• /
• pp.356-364
• /
• 1997

To evaluate the clinical utility of Tc-99m MIBI scan in the detection of residual thyroid tissue or metastatic lesion in postoperative thyroid cancer patients, we compared Tc-99m MIBI scan with I-131 diagnostic and therapeutic scan in 30 postoperative well-differentiated thyroid cancer patients. Thyroglobulin levels of both on and off thyroid hormone medication and antithyroglobulin antibody were tested [Tg(on), Tg(off)]. Positive rates for I-131 diagnostic and Tc-99m MIBI scan were 81% and 68% respectively. Concordance between I-131 diagnostic and Tc-99m MIBI scan was observed in 15 cases; 12 positive and 3 negative respectively. Among the 6 cases with negative I-131 diagnostic scan and positive Tc-99m MIBI scan, 4 were Positive in the therapeutic I-131 scan We concluded that Tc-99m MIBI scan maybe a useful complementary modality to the currently established method of I-131 scan and serum thyroglobulin level in the detection of recurrent or metastatic thyroid cancer, especially in the case of negative I-131 diagnostic scan.