• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.53-61
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• 2013

Objectives: It is certain that Radioactive iodine thyroid uptake(RAIU) rate should be measured with the standard counts considering the thyroid gland depth in enlarged thyroid patients for the variation from geometric factors. The purpose of this paper is to consider the effects of geometric factors according to detector to source distance and the effective thyroid depth on RAIU rate with experiment test. Materials and Methods: I-131 370 kBq ($10{\mu}Ci$) point source was measured by Captus-3000 thyroid uptake system (Capintec, NJ, USA) with a change Detector-Source Distance from 20 cm to 30 cm at an interval of 1 cm. And we changed the Neck phantom surface-Source Depth in the phantom with 1 cm, 2 cm, 5 cm using the neck phantom in order to reproduce the effective thyroid depth. Results: Every experimental group follows power curve as inverse square curve ($$R2{\geq_-}0.915$$). The average count rates in the case not using a phantom and the every case applied the effective thyroid depth using a phantom was not identical each other. There was significant fluctuations upon the effective thyroid depths applied the effective thyroid depth above 1 cm in $364.4 keV{\pm}10%$ energy ROI (p<0.01). There was not significant difference between the count rates of 1 cm and 2 cm in $364.4keV{\pm}20%$ and $637.1keV{\pm}6.2%$ (p=0.354, p=0.397). In assumed RAIU rate from regression equation, $364.4keV{\pm}20%$ was lower difference than $364.4keV{\pm}10%$ as 6.42% and 5.09% per 1 cm. Every change of count rate upon depth appears decreased line on Linear Regression, but the case of $284.3keV{\pm}10%$ increased only. And also, The graphs of coefficient of variation upon depth increased as straight line on every experimental group. Conclusion: The result appears that application of $364.4keV{\pm}20%$ energy ROI is more suitable for reducing error from the effective thyroid depth. And also, we can estimate the error of 20 cm should be highly reduced than 30 cm for Inverse Square Law. Therefore, If there is not information of the thyroid depth, it is considered that the error from thyroid depth can reduce through set up energy ROIs for $364.4keV{\pm}20%$, and increase Detector-Source Distances.

• Radiation Oncology Journal
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• v.16 no.4
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• pp.517-529
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• 1998

Purpose : Although many studies have investigated the dosimetric aspects of stereotactic radiosurgery in terms of target volume, the absorbed doses at extracranial sites: especially the lens or thyroid - which are sensitive to radiation for deterministic or stochastic effect -have infrequently been reported. The aim of this study is to evaluate what effects the parameters of radiosurgery have on the absorbed doses of the lens and thyroid in patients treated by stereotactic radiosurgery, using a systematic plan in a humanoid phantom. Materials and Methods : Six isocenters were selected and radiosurgery was planned using the stereotactic radiosurgery system which the Department of Therapeutic Radiology at Seoul National University College of Medicine developed. The experimental radiosurgery plan consisted of 6 arc planes per one isocenter, 100 degrees for each arc range and an accessory collimator diameter size of 2 cm. After 250 cGy of irradiation from each arc, the doses absorbed at the lens and thyroid were measured by thermoluminescence dosimetry. Results : The lens dose was 0.23$\pm$0.08$\%$ of the maximum dose for each isocenter when the exit beam did not pass through the lens and was 0.76$\pm$0.12$\%$ of the maximum dose for each isocenter when the exit beam passed through the lens. The thyroid dose was 0.18$\pm$0.05$\%$ of the maximum dose for each isocenter when the exit beam did not pass through the thyroid and was 0.41$\pm$0.04$\%$ of the maximum dose for each isocenter when the exit beam Passed through the thyroid. The passing of the exit beam is the most significant factor of organ dose and the absorbed dose by an arc crossing organ decides 80$\%$ of the total dose. The absorbed doses of the lens and thyroid were larger as the isocenter sites and arc planes were closer to each organ. There were no differences in the doses at the surface and 5 mm depth from the surface in the eyelid and thyroid areas. Conclusion : As the isocenter and arc plane were placed closer to the lens and thyroid, the doses increased. Whether the exit beams passed through the lens or thyroid greatly influenced the lens and thyroid dose. The surface dose of the lens and thyroid consistently represent the tissue dose. Even when the exit beam passes through the lens and thyroid, the doses are less than 1$\%$ of the maximum dose and therefore, are too low to evoke late complications, but nevertheless, we should try to minimize the thyroid dose in children, whenever possible.

• The Korean Journal of Nuclear Medicine
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• v.9 no.1
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• pp.15-19
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• 1975

• Journal of Radiation Protection and Research
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• v.19 no.1
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• pp.69-80
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• 1994

The TCMI(Three-Compartment Model for iodine) computer code has been developed, which is based on the three-compartment model and the respiratory model recommended in ICRP publication 54. This code is able to evaluate the thyroid burden, dose equivalent, committed dose equivalent and urinary excretion rate as time-dependent functions from the input data: working time and the radioiodine concentration in air. Using the TCMI code, the time-dependent thyroid burdens, the thyroid doses and the urinary excretion rates were calculated for three specific exposure patterns : acute, chronic and periodic. Applicability as an internal dose evaluation method has been assessed by comparing the results with some operational experiences. Simple equations and tables are provided to be used in the evaluation of the thyroid burden and the resulting doses for given I-131 concentration in air and the working time.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.157-161
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• 2018

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.262-266
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• 2004

The parathyroid hormone plays a major role in the metabolism of calcium and phosphorus. In hypoparathyroidism the parathyroid glands are atrophied or absent associated with autoantibodies against parathyroid tissue. Pseudohypoparathyroidism is a metabolic disease caused by the disturbance in peripheral action of parathormone, but parathormone level is normal. In general, patients with pseudohypoparathyroidism have short stature, round face, brachydactylia, obesity, mental retardation, cataracts & ectopic calcifications on soft tissues. Dental manifestations are enamel hypoplasia, delayed eruption, blunting of root apex, hypodontia, pulp calcification, thickened lamina dura, excessive caries & malocclusion. In this case, intraoral examination showed enamel hypoplasia on the erupted permanent teeth & hypermobility on the remaining deciduous teeth. From the radiographic view severe dental anomalies were observed on canines and shortening and blunting of root apex was observed on mandibular incisors. Pathologic root resorption was also observed on deciduous teeth.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.719-725
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• 2020

Metastases to the thyroid gland have rarely been reported in clinical settings, and the thyroid gland is an uncommon site for breast carcinoma metastasis. We report a case of a 64-year-old breast cancer patient diagnosed with metastatic breast carcinoma in the thyroid gland after performing ultrasonography (US)-guided core needle biopsy (CNB) and subsequent total thyroidectomy. On US, the thyroid lesion appeared to be mildly enlarged with multiple internal hypoechoic lines and a few microcalcifications without mass formation. Under US-guidance, CNB was performed by targeting the area with microcalcifications and subsequently diagnosed as metastatic breast carcinoma. Total thyroidectomy revealed that the patient had metastatic invasive ductal carcinoma of the breast with lymphatic spread involving both lobes and the isthmus of the thyroid gland. Although the thyroid gland is an uncommon metastatic site, the unusual features of thyroid metastasis can be observed on US; thus, US-guided CNB effectively aids the diagnosis of thyroid metastasis.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.516-521
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• 2004

Background: Radioactive iodine (RAI) therapy and whole-body scanning are the fundamentals of treatment and follow-up of patients with differentiated thyroid cancer. It is generally accepted that a Thyroid-Stimulating Hormone (TSH) level of at least 30 ${\mu}U/ml$ is a prerequisite for the effective use of RAI, and that it requires 4-6 weeks of off-thyroxine to attain these levels. Because thyroxine withdrawal and the consequent hypothyroidism are often poorly tolerated, and occasionally might be hazardous, it is important to be certain that these assumptions are correct. We have measured serial changes in serum TSH after total thyroidectomy or withdrawl of thyroxine in patients with thyroid cancer. Subjects and Methods: Serum TSH levels were measured weekly after thyroidectomy in 10 patients (group A) and after the discontinuation of thyroxine in 12 patients (group B). Symptoms and signs of hypothyroidism were also evaluated weekly by modified Billewicz diagnostic index. Results: By the second week, 78% of group A patients and 17% of group B patients had serum TSH levels ${\geq}30{\mu}U/ml$. By the third week, 89% of group A patients and 90% of group B patients had serum TSH levels ${\geq}30{\mu}U/ml$. By the fourth week, all patients in two groups achieved target TSH levels and there were no overt hypothyroidism. Conclusion: in all patients, serum TSH elevated to the target concentration (${\geq}30{\mu}U/ml$) within 4 weeks without significant manifestation of hypothyroidism. The schedule of RAI administration could be adjusted to fit the needs and circumstances of individual patients with a shorter preparation period than the conventional.

• 대한핵의학회:학술대회논문집
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• 1981.05a
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• pp.118-118
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• 1981

• 대한핵의학회:학술대회논문집
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• 1981.05a
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• pp.119.3-120
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• 1981