• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.118-122
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• 1993

To evaluate the genotoxic effect of $^{131}I$, lymphocytes from 9 patients who underwent large dose (150 mCi) $^{131}I$ therapy after total thyroidectomy were studied for sister chromatid exchanges (SCE) before and after their first radioiodine treatments. Frequency of SCE (FSCE) was counted in chromosomes of 30 lymphocytes in each patients, and was expressed as numbers of SCE per cell. Numbers of leukocytes were also observed during $^{131}I$ therapy. Pretreatment FSCE ($4.2{\pm}0.7$) was not different from the control ($3.8{\pm}0.4$, p=0.17). However, the frequency was significantly elevated after $^{131}I$ administration (at the second day, $7.9{\pm}0.8$, p<0.001) and was diminished but still significantly elevated after a week (at 9th day, $6.4{\pm}0.6$, p<0.001). While counts of leukocytes in the peripheral blood showed no change (p> 0.05). In conclusion, chromatids of human lymphocytes were significantly damaged after $^{131}I$ treatment without any bone marrow supression. And the repair of SCE was not complete within one week.

• Korean Journal of Head & Neck Oncology
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• v.17 no.2
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• pp.174-178
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• 2001

Background and Objective: Percutaneous ethanol injection therapy has been used in the treatment of the benign thyroid diseases. Although the reported side-effects of the therapy was mild and transient, some side-effects including local or radiating pain are troublesome to the patients. Radioactive iodine-131($Ra-^{131}I$) also has been effectively and safely used for management of the benign thyroid diseases. So we developed the percutaneous intranodular injection therapy of $Ra-^{131}I$ as an alternative of percutaneous ethanol injection therapy. Materials and Methods: From December 1998 to October 1999, we treated 29 outpatients (25 women and 4 men, mean age: $47{\pm}12$ years). Inclusion criteria were follows; age >30 years, cytologically benign, with normal thyroid function, cold nodule on thyroid scintigram, solid or mixed natured nodules in sonographical evaluation. Nodular volume was estimated by sonography according to the ellipsoid formula. $Ra-^{131}I$(0.1mCi/ml) was administered in a single dose injection. Follow-up studies every 3 months consisted of full history, thyroid function test, and sonography. We determined the therapeutic response is effective if the volume reduction of the nodule occurred above 30%. Results: After at least 3 months follow-up, 11 patients showed effective response, 12 patients showed minimal or unchanged response and 6 patients showed progression. Although side-effects such as injection pain, febrile reaction, and hormonal changes were absent, an infectious complication in injection site was developed from 1 case. Conclusion: Although we need a more prolonged follow-up to evaluate the delayed sequelae, we can suggest that percutaneous intranodular injection therapy of $Ra-^{131}I$ may be an attractive non-surgical treatment in selected cases of benign thyroid nodules.

• The Korean Journal of Nuclear Medicine
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• v.34 no.2
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• pp.107-118
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• 2000

Purpose: To evaluate the effectiveness of radioiodine treatment for metastatic thyroid carcinoma, we reviewed results of radioactive iodine treatment in patients with functional lung or bone metastases. Materials and Methods: Of 760 patients who were treated for differentiated thyroid cancer between 1984 and 1998, we detected pulmonary metastases and bone metastases in 76 patients (10.0%) and 20 patients (2.6%), respectively. Among them, we could evaluate the effectiveness of I-131 therapy in 53 patients with lung metastases and 15 patients with bone metastases. Results: Of 53 patients who received I-131 therapy with a mean cumulative dose of 26.2 GBq (1.1-84.4 GBq) for pulmonary metastases, metastatic lung lesions completely resolved in 19 patients (35.8%) and improved in 22 patients (41.5%). In 13 of 19 patients with complete remission of pulmonary metastases, the total accumulated dose of I-131 was less than 18.5 GBq. We found 43 sites of metastatic bone lesions in 15 patients with bone metastases. Of 29 lesions which received I-131 therapy, metastatic lesions improved in 14 sites (48.3%), but did not change or progress in 15 sites (51.7%) despite the I-131 therapy. Three lesions were completely cured with a combination treatment of surgery(${\pm}$ external radiotherapy) and I-131 therapy, and the other 11 lesions improved. Conclusion: Radioactive iodine treatment gives favorable results for pulmonary metastases. However, for bone metastases, there might be a need to use combination therapy including I-131 and surgery or external irradiation.

• 대한핵의학회:학술대회논문집
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• 1973.11a
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• pp.51.1-51.1
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• 1973

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.265-275
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• 2000

The thyroid gland is an interesting endocrine organ where a spectrum of tumors with different behavior arise. At one end of spectrum there is differentiated thyroid carcinoma (DTC) with excellent prognosis, whereas at the other end of the spectrum is anaplastic thyroid cancer which has universally poor outcome. Radioiodine (I-131) therapy has been in use for the treatment of thyroid diseases since 1946. It was introduced by Seidlin et al. 1) Although the use of I-131 has been vouge for a long time, its use in therapy for well differentiated thyroid cancer is still controversial 2). This is because, thyroid cancers (TC) are generally slow growing tumors, with low mortality and normal spans of survival. To record recurrence and mortality, long term follow up studies over a period of two to three decades are needed to establish definite conclusions on the acceptable mode of treatment The incidence of the disease being very low a large number of cases needed to establish a meaningful statistical data is lacking as most published reports feat with small series. Here again in the problem encountered are the differing protocols for treatment with I-131, the indications for treatment which may include or exclude ablation of residual thyroid tissue, cervical nodal and distal metastases. The dosage of I-131 used for ablation of residual thyroid tissue and metastatic disease also vary. The most reliable conclusion regarding I-131 treatment are obtained from studies reported on a large series of patients followed over a period of 2 decades or more from a single institute with a more or less unchanged protocol of management.

• Journal of the Korean Society of Radiology
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• v.7 no.3
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• pp.251-257
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• 2013

Spatial dose rates of high dose $^{131}I$ therapy patients were Measured Three dimensional (X, Y, Z) distributions. I have constructed geometrical an aluminum support structure for spatial dose meters placed in 5 different heights, 8 different azimuthal angles, 6 different time interval and distance 100 cm from High dose$^{131}I$ therapy patients. when the height of vertical plane Spatial dose distribution is 100 cm, the Spatial dose rates is max and the error range is low. the vertical plane Spatial dose rates was found to be 71.85 ${\mu}Sv/h$ on the average at a distance of 100 cm, height 100 cm, from the patients 24 hours after $^{131}I$ oral administration. I divided 12 patients into two groups. I have analysed group A (drinking 5 L water) and group B (drinking 3 L water) in order to measure decrease spatial dose rates. I have found the spatial distributions of patient dose rates is $44.9{\pm}7.2$ ${\mu}Sv/h$ in group A and $100.3{\pm}8.1$ ${\mu}Sv/h$ in group B by 24 after $^{131}I$ oral administration. the reduction factor was found to be approximately 54 % through drinking 5 L water during 24 hours.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.339-345
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• 1997

To evaluate the effectiveness of I-131 in ablation of residual thyroid tissue, we analyzed 350 patients with thyroid cancer who were treated with various doses of I-131 after surgery for thyroid cancer Two hundred fifty five patients were treated with 1.1GBq(30mCi) of I-131 for ablation of remnant thyroid and one hundred seventeen patients received more than 2.8GBq(75mCi) of I-131. We determined the effectiveness of ablation by following I-131 whole body scan. Absent visible uptake or minimal uptake in thyroid tissue were considered as successful ablation. Of 255 patients who received doses of 30mCi I-131 therapy, 131 patients(51%) showed successful ablation of residual thyroid tissue with $2.6{\pm}1.7$ times of I-131 therapy. Of 117 patients who received doses of the more than 75mCi I-131, 84 patients(72%) had successful remnant thyroid ablation with $1.6{\pm}1.1$ times of I-131 therapy, According to the extent of surgery, successful ablation rates were 78%, 62%, 54%, 33% in patients who underwent total thyroidectomy, subtotal thyroidectomy, lobectomy and isthmectomy, lobectomy or tumorectomy, respectively. This study showed that ablation of remnant thyroid after surgery with 30mCi I-131 was successful only in 50%. Therefore, in cases of patients with high risk for recurrence, we recommend high dose I-131 for ablation of remnant after total thyroidectomy.

• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.319-327
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• 1995

$^{131}I$-metaiodobenzylguanidine(MIBG) has been used for the diagnosis and treatment of neural crest tumors. We report our experience with this agent in 8 patients[1 multiple endocrine neoplasia(MEN) type IIb; 2 malignant pheochromocytoma; 5 medullary thyroid carcinoma(MTC)]. The therapeutic procedure consisted of 30-200 mCi of $^{131}I-MIBG$ administered by slow I.V. infusion, given at 3-6 months intervals. Commutative activity ranged from 150 mCi to 410 mCi, in 1 to 4 courses. $^{131}I-MIBG$ therapy resulted in significant disease free interval in 1 malignant pheochromocytoma(no measurable lesion) after surgery; complete hormonal and tumoral response in 2 MTC(1 MEN IIb): stable disease in 1 recurred pheochromocytoma(MEN IIb): stable disease but symptomatic improvement in 1 MTC, progressive disease in 1 malignant pheochromocytoma and 2 MTC. The patients who showed progression appeared to have large inoperable tumors or postoperative remnant tumors.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.2
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• pp.129-136
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• 2009

Purpose: To determine optimal imaging time for diagnostic I-123 whole body scan in the follow-up of patients with differentiated thyroid cancer(DTC), we compared the image quality of 6- and 24-hour images of the same subjects. Materials and Methods: Four hundred ninety-eight patients(M:F = 55:443, Age $47.6{\pm}12.9$ years) with DTC who had undergone total thyroidectomy and I-131 ablation therapy underwent diagnostic whole body scanning 6 hour and 24 hour after oral ingestion of 185 MBq(5 mCi) of I-123. Serum thyroglobulin measurement and ultrasonography of the neck were performed at the time of imaging. In 40 patients underwent additional I-131 therapy, post-therapy I-131 images were obtained and compared with diagnostic I-123 images. Results: In 440 patients(88.4%), 6- and 24-hour diagnostic I-123 images were concordant, and 58 patients(11.6%) showed discordant findings. Among 58 discordant patients, 31 patients showed abnormal tracer uptake on only 6-hour image, which turned out false-positive findings in all cases. In 12 patients with positive findings on only 24-hour image, remnant thyroid tissue(4 patients) and cervical lymph node metastasis(3 patients) were presented. Among 40 patients underwent additional I-131 therapy, 6-hour and 24-hour images were discordant in 13 patients. All 5 patients with abnormal uptake on only 6-hour image revealed false-positive results, whereas most of 24-hour images were concordant with post-therapy I-131 images. Conclusion: I-123 imaging at 24-hour could reduce false-positive findings and improve diagnostic accuracy, compared with 6-hour image in the follow-up of patient with DTC.

• Nuclear Medicine and Molecular Imaging
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• v.41 no.3
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• pp.218-225
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• 2007

Purpose: Postoperative thyroid remnant radioablation therapy is necessary to reduce the recurrence and mortality rates as well as to prepare the patients for a proper long term surveillance of well-differentiated thyroid cancers. The radiation safety rules of the government require the patient to be isolated in a hospital if the expected radiation exposure to the family members would be greater than 5 mSv (500 mRem). The purpose was to measure the radiation received by the family members of patients who received large doses of NaI-131. Material and Methods: We have administered 12 therapy doses ranging from 3.70-5.55 GBq (100 to 150 mCi) to 11 patients, and released them immediately if they met the radiation safety criteria. Informed consent was obtained from the subjects prior to the therapy, and each of them agreed to follow written radiation safety instructions. TLD badges were used to measure the radiation dose received by the family members and the room adjacent to the patient's bed room during the first 72 hours. Results: The average dose received by the family members who spent the most time in the closest distance with the patients was 0.04 mSv with a range of 0.01-0.17 mSv. Even the highest dose was only about 3% of the limit set by the government. The average radiation dose to the outer wall of the patient's room was 0.15 mSv. Conclusion: It is concluded that I-131 ablation therapy can be administered to outpatients safely to thyroid cancer patients who meet the established radiation safety criteria and follow the instructions.