• The Korean Journal of Nuclear Medicine
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• v.14 no.2
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• pp.35-40
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• 1980

In order to compare the therapeutic effect as well as side effects between antithyroid therapy and radioiodine therapy in hyperthyroidism, the author evaluated 111 cases of hyperthyroidism which were composed of 57 patients with antithyroid treatment, 23 patients with combined treatment comprising of antithyroid and radioactive iodine ($^{131}I$) and 31 patients with treatment of $^{131}I$ alone. The $^{131}I$ treatment was limited to older age, above 20 years of age, and not employed in patients with pregnancy and lactation. The patients treated with antithyroid belonged to relatively younger age, and also milder in symptoms and thyroid function tests. The remission rate of antithyroid therapy group was 97.8% within 16 months. Among them the early remission rate occured within 4 months was found to be 21.7%. The combined therapy group, having prescribed more severe cases, showed the remission rate to be 75% within 16 months. The remission rate of $^{131}I$ therapy group revealed 90.9% within 16 months. Among them the early remission rate taking place within 4 months disclosed 16.7%. The side effects of antithyroid drug, propylthiouracil, were noted as follows: itching (2.7%) skin rashes (1.3%), and adverse enlargement of goiter (10.7%). The side effects $^{131}I$ therapy were transient hypothyroidism(3.9%) permanent hypothyroidism (7.8%) and itching (2.0%).

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.214-219
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• 1998

Objectives: To assess the effectiveness of the low-dose(30mCi) I-131 ablation therapy for remnant thyroid tissue following total thyroidectomy for differentiated thyroid cancer. Methods: Between March 1995 and December 1997, forty-eight patients were given ablative doses(30mCi) of I-131 after total thyroidectomy for differentiated thyroid cancer in the presence of I-131 uptake in remnant thyroid tissue. Effective ablation of remnant thyroid tissue was determined by following I-131 whole body scan. if remnant thyroid tissue remained, we repeated the same management at 6 months interval. Results: Thirty-eight(79.1%) patients had papillary, 8(16.7%) follicular, 1(2.1%) medullary and 1(2.1%) Hurthle cell type cancer. Forty-eight patients underwent total thyroidectomy, among those central neck dissection was performed in 35 cases, and modified radical neck dissection in 14 cases. Postoperative complication developed in 8 cases, which included 4 cases of transient hypoparathyroidism, 1 case of permanent hypoparathyroidism, 2 cases of transient recurrent laryngeal nerve palsy, and 1 case of wound hematoma. There were significant remnant thyroid tissue in 46 cases(95.8%) of patients after total thyroidectomy, which could be ablated by low dose(30mCi) I-131. There were no statistical difference between operative procedures and number of treatment of I-131. Conclusions: These results suggested that repeated low-dose(30mCi) I-131 therapy would be needed, therefore, high -dose I-131 therapy could be considered as ablation therapy for the remnant thyroid tissue after total thyroidectomy for differentiated thyroid cancer.

• The Korean Journal of Nuclear Medicine
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• v.35 no.3
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• pp.117-124
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• 2001

Serum thyroglobulin measurement and I-131 whole-body scintigraphy (WBS) are well-established methods for the detection of recurrence in the follow-up of patients with thyroid carcinoma. However, inconsistent results are observed frequently, and these two methods are not always able to detect recurrence. In some patients, serum thyroglobulin level is elevated but the WBS is negative, because the recurrent tumor is too small and below the sensitivity of the diagnostic scan, or there is a dissociation between thyroglobulin synthesis and the iodine frapping mechanism. In such cases, various nuclear imaging methods including Tl-201 Tc-99m-sestamibi, and F-18-FDG PET can be used besides anatomical imaging methods. Among them, FDG PET localizes recurrent lesions in WBS-negative thyroid carcinoma with high accuracy. Several studies have suggested that empirical high-dose I-131 therapy resulted in a high rate of visualization in post-therapy scans with evidence of subsequent improvement. An important question is when to operate on patients with recurrent tumor. We believe that surgical removal is the best means of treatment for patients with localized persistent tumor, despite the high-dose I-131 therapy. with tumor in thyroid remnant, and with isolated recurrence in the lymph node, lung or bone. In addition, we recommend palliative resection of locally unresectable mass with subsequent treatment with high-dose I-131 therapy. Before I-131 therapy, the evaluation of sodium-iodide symporter expression in thyroid carcinoma can predict iodine uptake. Retinoic acid is known to induce redifferentiation, and to enhance I-131 uptake in thyroid carcinoma. Retinoic acid therapy may represent an alternative approach before high-dose I-131 therapy.

• The Korean Journal of Nuclear Medicine
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• v.35 no.2
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• pp.83-88
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• 2001

Purpose: The purpose of this study was to ascertain whether radiation adaptive response could be induced by high dose I-131 therapy in patients with differentiated thyroid cancer. Materials and Methods: Lymphocytes from 21 patients (7 males, 14 females, mean age $55{\pm}12$ years) were collected before and after administration of 5,550 MBq (150 mCi) I-131. They were exposed to a challenge dose of 1 Gy gamma rays using a Cs-137 cell irradiator. The number of ring-form (R) and dicentric (D) chromosomes was counted under the light microscope, and used to calculate the frequency of chromosomal aberration. Ydr, which was defined as the sum of R and D divided by the total number of counted lymphocytes. Results: Ydr in patients before I-131 therapy ($0.09{\pm}0.01$) was not different from that of controls ($0.08{\pm}0.01$). Ydr was significantly increased to $0.13{\pm}0.02$ (p<0.0001) after I-131 therapy. Increase of Ydr after the challenge irradiation of 1 Gy was significantly lower in patients after I-131 therapy than before I-131 therapy ($0.17{\pm}0.03\;vs\;0.21{\pm}0.02$, p<0.0001). Cycloheximide (CHM), an inhibitor of protein synthesis, abolished this effect. Ydr after CHM ($0.20{\pm}0.01$) was significantly higher than Ydr after I-131 therapy ($0.17{\pm}0.03$, p<0.0001), but was not different from Ydr before I-131 therapy ($0.21{\pm}0.02$).Conclusion: High dose I-131 therapy induces an adaptive response in peripheral lymphocytes of patients with well-differentiated thyroid cancer, which is associated with protein synthesis.

• Clinical and Experimental Pediatrics
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• v.51 no.2
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• pp.214-218
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• 2008

Neuroblastoma is one of the most common extracranial solid tumor of childhood, and treatment of refractory neuroblastoma remains a significant clinical problem. Iodine-131-metaiodobenzylguanidine ($^{131}I-MIBG$) therapy is an alternative approach to treat stage IV neuroblastoma. We report the palliative effect of $^{131}I-MIBG$ in three cases of relapsed neuroblastoma after autologous peripheral blood stem cell transplantation. $^{131}I-MIBG$ is an effective and relatively nontoxic palliative therapy resulting in reduction of pain and prolongation of survival.

• The Korean Journal of Nuclear Medicine
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• v.33 no.6
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• pp.493-501
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• 1999

Purpose: We conducted a comparative study to evaluate the diagnostic values of T1-201, Tc-99m MIBI and I-131 scans in the follow-up assessment after ablative I-131 therapy in differentiated thyroid cancer. Materials and Methods: The study population consisted of 20 patients who underwent surgical removal of thyroid cancer and ablative radioactive iodine therapy, and followed by one or mote times of I-131 retreatments (33 cases). In all patients, T1-201, Tc-99m MIBI, diagnostic and therapeutic I-131 scans were performed and the results were analyzed retrospectively. Also serum thyroglobulin levels were measured in all patients. The final diagnosis of recurrent or metastatic thyroid cancer was determined by clinical, biochemical, radiologic and/or biopsy findings. Results: Positive rates (PR) of Tc-99m MIBI, T1-201, diagnostic and therapeutic I-131 scans in detecting malignant thyroid tissue lesions were 70% (19/27), 54% (15/28), 35% (17/48) and 63% (30/48), respectively. The PR in the group of 20 cases (28 lesions) who underwent concomitant T1-201 and I-131 scans were in the order of therapeutic 131 scan 71%, T1-201 scan 54% and diagnostic I-131 scan 36%. There was no statistically significant difference between T1-201 and diagnostic I-131 scans (p>0.05). In the group of 20 cases (27 lesions) who underwent concomitant Tc-99m MIBI and I-131 scans, the PR were in the order of Tc-99m MIBI scan 70%, I-131 therapeutic scan 52% and I-131 diagnostic scan 33%. The PR of Tc-99m MIBI was significantly higher than that of diagnostic I-131 scan (p<0.05). Conclusion: Tc-99m MIBI scan is superior to diagnostic I-131 scan in detecting recurrent or metastatic thyroid cancer following ablation therapy in patients with differentiated thyroid cancer. T1-201 scan did not showed significantly higher positive rate than diagnostic I-131 scan. Instead of diagnostic I-131 scan before the I-131 retreatment, Tc-99m MIBI scan without discontinuing thyroid hormone replacement would be a prudent and effective approach in the management of these patients.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.109-113
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• 1998

We report a 37 year-old-female patient with papillary thyroid cancer treated by surgery who demonstrated residual thyroid and bilateral breast uptake on a diagnostic I-131 whole body scan. She had an extrathyroidal extension needing I-131 ablative therapy. Her galactorrhea was investigated and treated with low doses of bromocriptine prior to I-131 therapy. Her galactorrhea was due to the decreased secretion of PIF induced by empty sella.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.6
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• pp.582-587
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• 2009

A 59-year-old woman who was diagnosed with malignant pheochromocytoma underwent $^{18}F$-fluorodeoxyglucose positron emission tomography/computed tomography ($^{18}F$-FDG PET/CT). She had undergone left adrenalectomy for pheochromocytoma 4 years previously. Recent multiple metastatic pulmonary nodules were noted on the chest X-ray. After treatment with $^{131}I$-metaiodobenzylguanidine ($^{131}I$-MIBG) with 7.4 GBq, post-therapy $^{131}I$-MIBG scintigraphy depicted multiple distant metastases including lung, liver, abdominal para-aortic and mesenteric lymph nodes. $^{18}F$-FDG PET/CT also depicted multiple metastases in lung, liver, and abdominal para-aortic lymph nodes, but some lesions were not shown. In this case, $^{131}I$-MIBG scintigraphy found additional lesions in metastatic malignant pheochromocytoma.

• The Korean Journal of Nuclear Medicine
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• v.37 no.2
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• pp.120-127
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• 2003

Purpose: To evaluate diagnostic sensitivity of nuclear imaging in the detection of residual thyroid tissue and metastatic lesion, we have compared neck scintigrams with Tc-99m pertechnetate (Tc-99m scan) and high dose I-131 iodide (I-131 scan) in patients with differentiated thyroid cancer. Subjects and Methods: One hundred thirty-five thyroidectomized patients for differentiated thyroid cancer were enrolled in this study. Twenty-three had a previous history of radioiodine therapy. Planar and pin-hole images of anterior neck with Tc-99m were acquired at 20 minutes after injection, followed by I-131 scan three days after high-dose radioiodine therapy within 7 days interval. Patients were asked to discontinue thyroid hormone replacement more than 4 weeks. Results: All subjects were in hypothyroid state. Seventy out of 135 patients (51.9%) showed concordant findings between Tc-99m and I-131 scans. I-131 scan showed higher number of uptake foci in all of 65 patients showing discordant finding. Tc-99m scan showed no thyroid bed uptake in 34 patients, whereas 23 of them (67.6%) showed bed uptake in I-131 scan. Tc-99m scan did not show any uptake in thyroid bed in 11 of 112 patients without previous history of radioiodine therapy, but 9 of them showed bed uptake in I-131 scan. Tc-99m scan showed no bed uptake in all of the 23 patients with previous history of radioiodine therapy, in contrast 14 of them (60.9%) showed bed uptake in I-131 scan. Conclusion: These results suggest that Tc-99m scan has poor detectability for residual thyroid tissue or metastatic lesion in thyroidectomized differentiated thyroid cancer patients, compared to high dose I-131 therapy scan. Tc-99m scan could not detect any remnant tissue or metastatic lesion in patients with previous history of radioiodine treatment, especially.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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• pp.451-459
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• 1995

Thirty-eight patients with metastatic well-differentiated thyroid carcinoma treated with 200mCi $^{131}I$ were studied. There were false negative serum thyroglobulin values during TSH suppression or at anti-thyroglobulin antibody(+) and discrepancies between findings of whole body scan and serum thyroglobulin level. After one to five cycles of 200mCi $^{131}I$ therapy, complete remission and partial remission were achieved at 5.3% and 57.9%, respectively. We concluded that all of serum thyroglobulin, TSH, anti-thyroglobulin antibody, $^{131}I$ or $^{123}I$ whole body scan were necessary in follow up of metastatic well-differentiated thyroid carcinoma. Also, if there was no response after repetitive 200mCi $^{131}I$ therapy, higher doses of $^{131}I$ therapy should be considered.