• 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.

• Journal of the Korean Society of Radiology
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• v.5 no.6
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• pp.309-313
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• 2011

It is necessary for patients to wait twice for the thyroid examination of thyroid uptake measurement and thyroid scan by using $^{99m}Tc$-pertechnetate. In the study, a method of simultaneous examination of thyroid uptake measurement and thyroid scan by one intravenous injection of $^{99m}Tc$-pertechnetate was suggested by using attenuation filter. As a result, there was a significant correlation between control group and experimental group according to existence of attenuation filter. Consequently, the simultaneous examination of thyroid uptake measurement and thyroid scan by one intravenous injection can be applied clinically.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.346-355
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• 1997

To evaluate the utility of I-131, T1-201 scintigraphy, and serum thyroglobulin(Tg) in the follow-up of differentiated thyroid cancer, we compared retrospectively the data from 33 patients who underwent total or subtotal thyroidectomy. I-131 scintigraphy was performed after optimal endogenous TSH stimulation ($TSH>50{\mu}U/ml$). Total 41 cases of I-131 and T1-201 scintigraphy pairs were examined. Concomitant serum thyroglobulin levels were measured for 41 pairs of scan. Tg-off levels(that measured after discontinuation of the thyroid hormone) higher than 40ng/m1 were considered positive, and Tg-on levels(that measured during the thyroid hormone replacement) higher than 5ng/ml were considered positive. The concordance rates between I-131 therapeutic scintigraphy and T1-201 scintigraphy was 48% in the 38 case of total scan pairs(59% in the 17 cases of postoperative preablation group, and 38% in the 21 cases of postoperative postablation group). Of 17 studies before the I-131 ablation therapy(preablation group), 7 showed positive I-131 therapeutic scintigraphy despite of negative T1-201 scintigraphy. Among patients with negative I-131 therapeutic scintigraphy, no patients had abnormal T1-201 uptake. However, of 21 studies which were done after radioiodine therapy(postablation group) 6 had abnormal uptake on T1-201 scintigraphy which were not seen on I-131 therapeutic scintigraphy, and Tg-off levels also elevated in this 4 of 6 cases. As a result, I-131 therapeutic scintigraphy showed highest positive rate at postoperative preablation follow-up study in differentiated thyroid cancer patients. T1-201 scintigraphy may be useful in postablation studies, and the use of the combined modalities(T1-201 and Tg levels) provides a higher diagnostic yield.

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

• The Korean Journal of Nuclear Medicine
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• v.34 no.1
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• pp.22-29
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• 2000

Purpose: We compared the first postoperative diagnostic and post-therapy scans of patients who received therapeutic doses of I-131, to investigate the difference in clinical outcomes between patients with concordant findings of diagnostic and post-therapy scans and patients with discrepant (more lesions in post-therapy scan) findings. Materials and Methods: The first postoperative diagnostic and post-therapy radioiodine scans of one hundred forty three patients with well differentiated thyroid carcinoma were reviewed. Diagnostic scans were obtained following ingestion of 185 MBq of I-131 and post-therapy scans were obtained after therapeutic dose of $3.7{\sim}9.3$ GBq of I-131. Successful ablation was defined as no radioiodine uptake on diagnostic radioiodine scan and normal range of serum thyroglobulin level (<10 ng/ml) during serum TSH elevation. Results: Discrepant scan findings were noted in 25 (17.5%) patients. Twenty-two patients (15.4%) showed more lesions in post-therapy scan and 3 patients (2.1%) showed stunning effect. Nine (64.3%) of 14 patients with distant metastasis revealed metastatic lesion(s) only on post-therapy scan. Stunning effect was considered as sublethal damage in 1 patient and treatment by a diagnostic dose in 2 patients. Ablation was achieved in 52.4% (75/143) of all patients. Ablation rate and mean cumulative radioiodine dose were not different statistically between concordant and discrepant groups. Conclusion: There were 17.5% difference between diagnostic and post-therapy scan findings when using 185 MBq of I-131 as a diagnostic dose. However, 64.3% of distant metastases were revealed only on post-therapy scan. Ablation rate and mean cumulative radioiodine dose were not different statistically between concordant and discrepant groups. The stunning effect was considered as not only sublethal damage but also treatment by a small diagnostic dose of radioiodine.

• 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.

• 대한핵의학회:학술대회논문집
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• 1987.05a
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• pp.113.1-113.1
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• 1987

• The Korean Journal of Nuclear Medicine
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• v.37 no.2
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• pp.128-134
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• 2003

섬유성 골이형성증은 비정상적인 섬유성 골조직으로 대체되며 느리게 진행하는 골병변이다. 섬유성 골이형성증과 부갑상선기능항진증은 흔하게 관찰되는 질환이나 McCune-Albright 증후군 없이 일차성 부갑상선기능항진증에 동반된 섬유성 골 이형성증은 거의 보고된바가 없다. Tc-99m MDP 골스캔이 섬유성 골이형성증의 진단에 유용하다고 알려져 있으나, Tc-99m MIBI 영상은 아직 보고된 바가 없다. 저자들은 McCune-Albright 증후군이 없이 부갑상선기능항진증에 동반된 섬유성 골 이형성증의 Tc-99m MIBI 스캔과 Tc-99m MDP 골스캔의 영상을 비교하였다. Tc-99m MDP 골스캔상 병변 부위에서 증가된 섭취 소견을 보였으며, Tc-99m MIBI 조기영상에서도 동일한 위치에서 섭취증가가 관찰되었다. 2시간 지연 Tc-99m MIBI 영상에서는 Tc-99m MIBI의 섭취가 배출되는 소견을 보였다. 섬유성 골이형성증 병변에서 Tc-99m MIBI 스캔이 유용할 것이라고 생각하며, 섬유성 골이형성증 병변에서 Tc-99m MIBI의 섭취를 증가시키는 인자에 대한 더 많은 연구가 필요할 것으로 생각한다.

• 대한핵의학회:학술대회논문집
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• 2001.11a
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• pp.45.1-45.1
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• 2001

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.31-36
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• 1994

We studied 65 patients with hypercalcemia who had heed performed $^{201}Tl/^{99m}Tc$ subtraction scan, 21 of them were confirmed as parathyroid tumor (19 adenoma, 2 carcinoma). The diagnostic sensitivity of $^{201}Tl/^{99m}Tc$ subfraction scan for detecting parathyroid mass was 90.5%, specificity was 97.6%, ultrasonography was 80.6%, 58.8%, respectively. The causes of two false negative cases were relatively small size ($1.5{\times}1{\times}0.8cm$) compared to remainig cases and poor thallium uptake due to cystic necrosis of parathyroid adenoma. The one false positive case was non-functioning thyroid nodule. $^{201}Tl/^{99m}Tc$ subtraction scan was simple, effective diagnostic tool and superior to ultrasonography for evaluating the parathyroid mass with high sensitivity and specificity.