Radioiodine (131I) Therapy of Graves' Disease: Use of the New High Resolutional Ultrasonic Scanner for the Determination of the Accurate Weight of the Thyroid Gland.

Nagayama, Yuji; Ashizawa, Kiyoto; Matsuo, Keiichi; Inoue, Shuji; Harakawa, Seijiro; Hirayu, Hideshi; Yamashita, Shunichi; Izumi, Motomori; Nagataki, Shigenobu

doi:10.1507/endocrj1954.36.359

Cited by 8 publications

(11 citation statements)

References 20 publications

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“…Previous studies demonstrate the radioresistance of larger goiters. 6,ll Therefore, in the present studies the actual incidence of late hypothyroidism might be even somewhat lower than we have calculated. In either case, no difference between eu-and hypothyroid groups in several factors that may influence the long-term effect of 1311 treatment suggests that other uncertain factor(s), including the inhomogeneity of iodine distribution in the thyroid or unequal sensitivity of the thyroid cells to radiation, may influence the long-term as well as the short-term effects of 131I treatment of Graves' disease.…”

Section: Discussioncontrasting

confidence: 56%

“…Briefly, the weight of the thyroid gland was determined with the high resolution ultrasonic scanner as previously described. 5,6 The estimated thyroid volume obtained with this scanner has been found to be closely correlated with the actual weight at operation (correlation coefficient: 0.98 in Graves' disease and 0.99 in thyroid adenoma). 5 The 24-hour 1311 uptake of the tracer dose was measured after an iodine-restricted diet for at least 1 week.…”

Section: Methodsmentioning

confidence: 70%

“…Ten out of 13 patients were those mentioned in our previous report who had been followed up for one year after 131I treatment. 6 The remaining three patients were not available for the present series of studies. The majority of these patients had adverse reactions to antithyroid drugs.…”

Section: Methodsmentioning

confidence: 99%

“…3,4 However, the high resolution ultrasonic scanner that we have developed has been reported to be capable of very accurate determining the weight of the thyroid glands,5 and has previously been introduced by our group for 131I treatment of Graves' disease. 6 Our studies have provided evidence that in our short-term follow-up studies (one year after treatment) the therapeutic radiation dosage should be increased as the gland size does, even if the gland size is accurately estimated by this ultrasound: all hyperthyroid Graves' patients with large thyroid glands (>sixty grams) remained hyperthyroid, whereas 80 % of hyperthyroid Graves' patients with small thyroid glands (>forty grams) became euthyroid one year after 80 Gy 131 I treatment. 6 But no long-term followup of 131I treatment based on accurate thyroid size has yet been performed.…”

Section: Introductionmentioning

confidence: 99%

“…6 Our studies have provided evidence that in our short-term follow-up studies (one year after treatment) the therapeutic radiation dosage should be increased as the gland size does, even if the gland size is accurately estimated by this ultrasound: all hyperthyroid Graves' patients with large thyroid glands (>sixty grams) remained hyperthyroid, whereas 80 % of hyperthyroid Graves' patients with small thyroid glands (>forty grams) became euthyroid one year after 80 Gy 131 I treatment. 6 But no long-term followup of 131I treatment based on accurate thyroid size has yet been performed. This may be important because the high incidence of late hypothyroidism is one of major disadvantages of 131I treatment, regardless of the methods used.…”

Section: Introductionmentioning

confidence: 99%

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Long-term follow-up studies on Iodine-131 treatment of hyperthyroid graves’ disease based on the measurement of thyroid volume by ultrasonography

et al. 1993

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In the present series of studies, the long-term (four year) effect of 80 Gy of 131I treatment was evaluated in patients with hyperthyroid Graves' disease whose thyroid volumes have been accurately estimated with a high resolution ultrasound scanner. One year after 131I treatment, 23.1% (3 out of 13 patients) remained hyperthyroid, 69.2% (9 out of 13) became euthyroid, and 7.7% (1 out of 13) were in a hypothyroid state. Since three patients in a hyperthyroid state one year after treatment were subsequently treated with either antithyroid drugs or additional 131I treatment, the remaining ten patients (9 euthyroid and 1 hypothyroid patients) have been followed up for three more years. Two patients developed a hypothyroid state three years after treatment and one patient four years after treatment. Overall, 60% (6 out of 10 patients) were in a euthyroid state and 40% (4 out of 10) in a hypothyroid state, four years after 80 Gy 131I treatment. There was no significant difference between eu- and hypothyroid groups in the sex ratio, age, radiation dose, therapeutic dose, thyroid gland volume, 24-hr 131I uptake, the effective half-life of 131I in the thyroid or the duration of hyperthyroidism. In our preliminary studies, the incidence of late hypothyroidism in our 131I treatment is similar to those previously reported. These suggest that uncertain factor(s), such as inhomogeneity of iodine distribution in the thyroid, unequal sensitivity of the thyroid cells to the radiation, and/or persistent destructive effects of the autoimmune process may influence the long-term effect of 131I treatment of Graves' disease.

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Section: Discussioncontrasting

confidence: 56%

Section: Methodsmentioning

confidence: 70%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Long-term follow-up studies on Iodine-131 treatment of hyperthyroid graves’ disease based on the measurement of thyroid volume by ultrasonography

et al. 1993

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Reduction in thyroid volume after radioiodine therapy of Graves' hyperthyroidism: results of a prospective, randomized, multicentre study

Peters

Fischer

Bogner

et al. 1996

Eur J Clin Investigation

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The reduction in thyroid size in 92 patients treated with radioiodine for Graves' thyrotoxicosis was monitored by ultrasound volumetry. The patients were randomly treated with either a standard 131I activity of 555 MBq or an activity calculated to deliver a thyroid dose of 100 Gy. Within 1 year after radioiodine treatment, a remarkable volume reduction of about 71% (median) (quantile 25% (Q 25) = 49%, Q 75 = 82%, n = 67) was observed. The bulk of this reduction (median 57%, Q 25 = 21%, Q 75 = 74%, n = 92) was found within the first 6 months. Statistical analysis reveals that the effect was clearly related to the thyroid dose actually achieved during therapy. The median reduction obtained 6 months after radioiodine application was 45% for < 100 Gy, 56% for 100-200 Gy and 67% for > 200 Gy (n = 28, 39, 25 respectively). Twelve months after radioiodine application, the effect became less evident: 53%, 68% and 75% respectively (n = 17, 29, 21). The higher median thyroid dose actually achieved by standard than by calculated activity (215 Gy vs. 116 Gy) explains the more pronounced volume reduction in the standard group than in the calculated group; 60% vs. 47% 6 months (n = 47, 45) after radioiodine treatments and 74% vs. 66% 12 months (n = 31,36) after radioiodine application. The relative reduction in thyroid size was just as marked in patients with large thyroids as in those with small glands. The goitre prevalence (thyroid volume > 20 mL in women and > 25 mL in men) was reduced from 73% to only 16% 1 year after radioiodine treatment. In patients with a thyroid volume of more than 60 mL, the median pretherapeutic thyroid volume of 102 mL was reduced to 29 mL. In conclusion, radioiodine treatment in Graves' hyperthyroidism sufficiently reduces thyroid volume in a dose-dependent manner. The findings of this study demonstrate that radioiodine is also an attractive mode of therapy for Graves' patients with substantial thyroid enlargement.

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Accuracy Considerations When Using Early (Four- or Six-Hour) Radioactive Iodine Uptake to Predict Twenty-Four-Hour Values for Radioactive Iodine Dosage in the Treatment of Graves' Disease

Morris¹,

Braunstein²

2000

Thyroid

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Although literature has offered methods to predict 24-hour radioactive iodine uptake values from early (4- to 6-hour) measurements, the resultant dosage errors have not been examined. Potential errors include underdosage, overdosage, and a failure to recognize rapid turnover patients (early-to-late uptake ratios > or = 1) who are at high risk for treatment failure and full-body radiation exposure. We developed and tested a novel method for minimizing error involved in using a single early uptake measurement to derive late uptake. From a retrospective analysis of 203 Graves' disease patients, receiver operating characteristic (ROC) curve analysis enabled us to identify patients likely to experience rapid turnover and therefore should receive 24-hour studies. Twenty-four-hour uptake measurements are necessary with 77% or more 4-hour uptake values and 80% or more 6-hour values. After eliminating these patients, we developed linear regression equations to predict the 24-hour uptake from 4-hour (n = 61) and 6-hour (n = 22) rule groups, testing their efficacy on separate 4-hour (n = 61) and 6-hour (n = 21) patient groups. We also used our test population to measure error in four early-to-late uptake conversion formulas presented in the literature. Error involved in these predictions ranged from a 10.6% overestimate for 4-hour calculations to a 5.9% underestimate for 6-hour calculations. When applied to two dosage formulas incorporating gland size, absorbed dose, and 24-hour uptake, average dosage error was 7%. In comparison to the other sources of error radioactive iodine (131I) dosimetry, potential error in predicting 24-hour uptake from 4- or 6-hour uptake values is low.

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Radioiodine (131I) Therapy of Graves' Disease: Use of the New High Resolutional Ultrasonic Scanner for the Determination of the Accurate Weight of the Thyroid Gland.

Abstract: In this series,

Cited by 8 publications

References 20 publications

Long-term follow-up studies on Iodine-131 treatment of hyperthyroid graves’ disease based on the measurement of thyroid volume by ultrasonography

Long-term follow-up studies on Iodine-131 treatment of hyperthyroid graves’ disease based on the measurement of thyroid volume by ultrasonography

Reduction in thyroid volume after radioiodine therapy of Graves' hyperthyroidism: results of a prospective, randomized, multicentre study

Accuracy Considerations When Using Early (Four- or Six-Hour) Radioactive Iodine Uptake to Predict Twenty-Four-Hour Values for Radioactive Iodine Dosage in the Treatment of Graves' Disease

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