• Korean Journal of Head & Neck Oncology
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• v.18 no.2
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• pp.173-178
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• 2002

Background and Objective: Factors that are associated with the recurrence after radioactive iodine ablation therapy have not been identified yet. The aim of this study is to elucidate the factors that are related to the recurrence after thyroid surgery of the thyroid papillary cancer followed by radioactive iodine ablation therapy. Patients and Methods: Fifty four cases who had underwent thyroid cancer surgery and postoperative radioactive iodine ablation therapy were included in this study. Mean followup duration was 7 years. There were 41 women and 13 men. Data analysis was done retrospectively with medical record review. Chi-square test and Fisher's exact test was used for the statistical analysis. Results: Age over 40, capsular invasion, and loca invasion were the factors that were associated with the high rate of recurrence. But sex, size of the tumor, multiplicity and extent of the surgery were not related to the recurrence. Conclusion: Without the curative resection of the tumor, radioactive iodine ablation therapy cannot lower the recurrence rate. So aggressive resection of the thyroid papillary cancer is important.The more data accumulated and the longer the followup, the easier we can reveal the recurrence-related factors of postoperative radioactive ablation therapy.

• Korean Journal of Head & Neck Oncology
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• v.14 no.1
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• pp.61-69
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• 1998

Objectives: The response rate of the radioactive iodine(RI) therapy with low dose was variable. Only a few studies reported the response and complication rate with high dose. The goal of this study was to access the ablation and complication rate after high dose of RI therapy (more than 100mCi) and to evaluate the factors affect the results. Material and Methods: During a period of 12 years, 225 patients received high dose of RI from 100 to 200mCi depending on the RI uptake in the whole body after total thyroidectomy. 100mCi of RI was given to 123 patients for ablation who showed the uptake only in the thyroid bed. 150mCi was given to another 84 patients for ablation who had uptake confined to the neck. The other 21 patients took more than 200mCi of RI because the whole body scan showed distant metastasis. Among these patients, the ablation and the complication rate was investigated. Results: Elevated level of the serum thyroglobulin(Tg) decreased less than 5ng/ml after RI therapy in all patients except two in the first group. The second group showed reduction of the serum Tg in 93%. Eighteen of the 21 patients in the third group are still alive after RI therapy. There were no fatal complications after high dose RI therapy and most of the complications were minimal and transient. The complication rate was not related with the dose of RI, age, sex, DNA flowcytometry, serum thyroglobulin level and the extent of node dissection. Conclusion: We concluded that RI therapy with high dose was very effective for thyroid ablation after operation and it also showed excellent results with minimal complications for treatment of metastatic lesions.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.4
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• pp.259-279
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• 2009

Radioiodine ablation therapy has been considered to be a standard treatment for patient with differentiated thyroid cancer after total thyroidectomy. Patients may need to be hospitalized to reduce radiation exposure of other people and relatives from radioactive patients receiving radioiodine therapy. Medical staffs, nursing staffs and technologists sometimes hesitate to contact patients in radioiodine therapy ward. The purpose of this paper is to introduce radiation dosimetry, estimate radiation dose from patients and emphasize the safety of radiation exposure from patients treated with high dose radioiodine in therapy ward. The major component of radiation dose from patient is external exposure. However external radiation dose from these patients treated with typical therapeutic dose of 4 to 8 GBq have a very low risk of cancer induction compared with other various risks occurring in daily life. The typical annual radiation dose without shielding received by patient is estimated to be 5 to 10 mSv, which is comparable with 100 to 200 times effective dose received by chest PA examination. Therefore, when we should keep in mind the general principle of radiation protection, the risks of radiation exposure from patients are low and the medical personnel are considered to be safe from radiation exposure.

• Journal of Medicine and Life Science
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• v.19 no.3
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• pp.95-102
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• 2022

This retrospective study aimed to investigate whether there was a difference in the success rate of removal of residual thyroid tissue in patients with the same cutoff serum thyroglobulin (Tg) value-measured 2 weeks after thyroid hormone withdrawal (THW)-for different radioactive iodine (RAI) activities. We identified 132 patients with papillary thyroid cancer who were treated with total thyroidectomy and RAI therapy to evaluate the efficacy of three radioactivities of I-131: 1,110, 3,700, and 5,550 MBq. Serum Tg testing was performed 1 week before RAI treatment and 2 weeks after THW (pre-Tg); the cutoff pre-Tg level was below 10 ng/mL. Stimulated Tg levels were measured on the day of I-131 administration (off-Tg). After 6 months of treatment, we compared the groups for complete ablation, defined as no uptake on a diagnostic I-131 scan, stimulated Tg level of <1.0 ng/mL, and Tg antibody level of <100 ng/mL. Ninety-five patients (72.0%) achieved complete ablation, with 57.1% (8/14), 78.2% (68/87), and 61.3% (19/31) in the 1,110 MBq, 3,700 MBq, and 5,550 MBq groups, respectively. There was no significant difference in the complete ablation rates between the three groups. In the multivariate analysis, the off-Tg level was a significant predictor of complete ablation. RAI therapy with low radioactivity (1,110 MBq) seemed sufficient for ablation in patients with papillary thyroid cancer with a pre-Tg level below 10 ng/mL. The off-Tg level is a promising and useful predictor of complete ablation after initial RAI therapy.

• 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.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.24 no.1
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• pp.33-40
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• 2013

Background and Objectives:This study is to objectively compare and analyze the acoustic changes in the patients with total thyroidectomy before and after RI therapy. Subjects and Methods:For this study, a total of 50 patients with total thyroidectomy were participated as subjects. Voice samples were obtained at the time of post-operation (Post-OP), before high-dose radioactive iodine therapy (Pre-RIT), and after high-dose radioactive iodine therapy (Post-RIT). Acoustic analysis, the maximum phonation time and K-VHI (Korea-Voice handicap index) were used for subjective evaluation. Results:According to the comparison analysis of the three periods, mFo (Hz) was significantly reduced in all of the vowels /a/ and /i/ as the hormone was discontinued. This can be related to the reduction in vocal range. As thyroid hormone was discontinued, Shim (%) and APQ (%) values, which are the parameters related to the degree of aggressiveness, showed a significant increase in the middle vowel /a/. As thyroid hormone was discontinued, emotional index was significantly decreased in VHI (voice handicap index). Conclusion:These results can be assumed that thyroid hormone suspension is related to the increased changes in the vocal intensity, the increase in noise and the reduction in vocal range. Emotionally, these data can be assumed that the responsive factors of one's own voice disorders were significantly decreased in the patients with vocal handicap.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.5
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• pp.375-382
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• 2008

A low iodine diet (LID) is the recommended preparation for radioactive iodine treatment. However, the recommended duration and stringency of LID are different among each recommendation. More stringent LID is expected in Korea because Korea is a iodine-rich region. We investigated the decrement of urine iodine excretion by two-week stringent LID for remnant thyroid ablation with radioactive iodine in Korean patients with thyroid cancer, prospectively. Material and Method: From November 2006, patients who referred to our hospital for remnant ablation after total thyroidectomy were included in this study. To decrease total body iodine, our protocol included three strategies. First, we checked medication which could inhibit the radioactive iodine uptake. Second, the date of 1-131 treatment was scheduled at least 3 months later if contrast agent had been used. The last strategy was two-week stringent LID education by specialized nutritionist. Before and after two-week stringent LID, 24hr-urine iodine was analyzed respectively. 24hr-urine creatinine was also analyzed for determining more valid 24hr urine sampling subgroup. Results: Total 51 patients were finally enrolled. Average of 24hr-urine iodine excretion was significantly lowered ($787{\pm}2242\;{\rightarrow}\;85{\pm}85\;{\mu}g/d$, p=0.03) after LID and 74.4% of patients reached below the recommended urine iodine excretion level ($<100\;{\mu}g/d$). In subgroup (n=14), similar results was showed ($505{\pm}666\;{\rightarrow}\;99{\pm}116\;{\mu}g/d$, p=0.05) and 78.6% of patients met the criteria. Conclusion: Most patients could reach below the recommended urine iodine level after two-week stringent LID. Therefore, in our opinion, at least two-week stringent LID should be recommended in Korea.

• Journal of Yeungnam Medical Science
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• v.32 no.2
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• pp.138-142
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• 2015

L-thyroxine (LT4) withdrawal prior to radioactive iodine (RAI) ablation therapy is a commonly used method for successful treatment of patients with papillary thyroid cancer (PTC). However, a prolonged period of hypothyroidism induced by LT4 withdrawal is sometimes associated with impaired quality of life and cardiopulmonary dysfunction in PTC patients. Furthermore, LT4 withdrawal may have a trophic effect on residual cancer by means of increased thyrotropin. We report on 2 cases of metastatic PTC patients with malignant pleural effusion (MPE) whose disease showed rapid worsening after LT4 withdrawal and RAI therapy. The first case is a 65-year-old woman who had PTC with multiple distant metastases and MPE. During LT4 withdrawal for RAI therapy, MPE showed rapid worsening, and the patient required repetitive therapeutic thoracentesis. The second case is a 49-year-old woman with PTC who underwent 3 additional operations for cancer recurrence in the neck lymph nodes and 6 times of RAI treatments. While preparing for the $7^{th}$ RAI treatment by withdrawing LT4, she developed MPE which became progressively aggravated after RAI therapy. Both patients experienced increased pleural effusion during the LT4 withdrawal period and a rise in the thyroglobulin level was observed after RAI therapy. MPE was not controlled with therapeutic thoracentesis and pleurodesis. Eventually, both patients died of rapid disease progression after RAI therapy. In summary, LT4 withdrawal may have an adverse effect on metastatic PTC patients, particularly those with MPE.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.3
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• pp.147-156
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• 2008

Purpose: All acts which are enforced from the radioactive iodine therapeutic team is a in its own way principle and provision. Therefore unification of all acts can not be appropriately. We will make the standard coherence. Materials & Methods: From 5 November, 2007 to 17 November 2007, we conducted a questionnaire survey of the nuclear medicine manager of 30 hospitals. The contents of a questionnaire is medical treatment section, patient management, prosecuting attorney section, waste management and safety supervision in about the patient and a questionnaire was drawn up in the method which selects an item. Results: 30 hospital agencies are operating purely for I-131 high dose ablation therapy. Diagnostic study and daily schedule had the difference of some. The most of education for the patients took charge of doctor and nurse. The satisfaction of education was evaluated as the high thing. The safety supervision of waste management accomplishment and Safety supervision the patient and the worker observed on the basis of atomic energy law. Conclusion: Specific standards with sufficient amount of information and practical contents should have been presented through the following data. However, it seems to be lacking in many aspects. Nevertheless, respondents rated 70.9%, which is relatively high, on the value of clinical utilization, and I am very thankful for the evaluation. For many years from now, it may seem necessary for a lot of research on the specific matters based on these data to be conducted.

• The Korean Journal of Nuclear Medicine Technology
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• v.12 no.1
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• pp.3-12
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• 2008

Purpose: Contaminated clothes and bedclothes of patients by mouth or with excrement are produced after Radioisotope $^{131}I$ treatment. In this paper, patient's clothes and bedclothes contaminated by radioactivity measured and radioactive waste wish to calculate optimum storage period. Material and Methods: The whole area of patients' clothes and bedclothes measured 70 patients, 12 males and 58 females, who had radioisotope $^{131}I$ therapy between August 2005 and February 2006. Assuming contamination is evenly distributed, the radioscope used to measure up to social toleration level at 7 day intervals. Results: Each optimum storage period of control group of 60 case and non control group of 10 case were average $44{\pm}16$ days and $32{\pm}13$ days. Decontamination effect of surface contamination for radioactive waste was average $83.66{\pm}15.15%$. Conclusion: It is important that classify radioactive waste according to difference of surface contamination. Result of this research, handling radioactive waste in optimum storage period may be useful.