Association between exposure to radioactive iodine after the Chernobyl accident and thyroid volume in Belarus 10-15 years later

Abstract Background While there is a robust literature on environmental exposure to iodine-131 (131I) in childhood and adolescence and the risk of thyroid cancer and benign nodules, little is known about its effects on thyroid volume. Methods To assess the effect of 131I dose to the thyroid on the volume of the thyroid gland, we examined the data from the baseline screening of the Belarusian-American Cohort Study of residents of Belarus who were exposed to the Chernobyl fallout at ages ≤18 years. Thyroid dose estimates were based on individual thyroid activity measurements made shortly after the accident and dosimetric data from questionnaires obtained 10-15 years later at baseline screening. During baseline screening, thyroid gland volume was assessed from thyroid ultrasound measurements. The association between radiation dose and thyroid volume was modeled using linear regression where radiation dose was expressed with power terms to address non-linearity. The model was adjusted for attained age, sex, and place of residence, and their modifying effects were examined. Results The analysis was based on 10,703 subjects. We found a statistically significant positive association between radiation dose and thyroid volume (P < 0.001). Heterogeneity of association was observed by attained age (P < 0.001) with statistically significant association remaining only in the subgroup of ≥18 years at screening (P < 0.001). For this group, increase in dose from 0.0005 to 0.15 Gy was associated with a 1.27 ml (95% CI: 0.46, 2.07) increase in thyroid volume. The estimated effect did not change with increasing doses above 0.15 Gy. Conclusions This is the first study to examine the association between 131I dose to the thyroid gland and thyroid volume in a population of individuals exposed during childhood and systematically screened 10-15 years later. It provides evidence for a moderate statistically significant increase in thyroid volume among those who were ≥ 18 years at screening. Given that this effect was observed at very low doses and was restricted to a narrow dose range, further studies are necessary to better understand the effect.

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Association Between 131I Exposure After the Chernobyl Accident and Thyroid Volume in Children in Belarus

Journal of the Endocrine Society ◽

10.1210/jendso/bvab048.1748 ◽

2021 ◽

Vol 5 (Supplement_1) ◽

pp. A856-A857

Author(s):

Ekaterina Chirikova ◽

Elizabeth K Cahoon ◽

Alexander Rozhko ◽

Vladimir Drozdovitch ◽

Mark P Little ◽

...

Keyword(s):

Thyroid Cancer ◽

Thyroid Gland ◽

Linear Regression ◽

Iodine Deficiency ◽

Dose Response ◽

Chernobyl Accident ◽

Dietary Habits ◽

Thyroid Volume ◽

Quadratic Term ◽

Activity Measurements

Abstract Thyroid enlargement can cause problems with swallowing or breathing and a decrease in accuracy of screening for thyroid cancer. Exposure to radioactive iodines after the 1986 Chernobyl accident is known to increase risk of thyroid cancer in those exposed at a young age, but little is known about its effects on thyroid volume, which could have important clinical implications. The objective of this study is to characterize the dose-response association between iodine-131 (131I) exposure and thyroid volume using data from a Belarusian-American cohort study of residents of Belarus exposed during childhood. Persons exposed to Chernobyl fallout in Belarus at the age of 18 years or younger had individual 131I doses to the thyroid gland estimated from direct thyroid activity measurements, radioecological and biokinetic models, and interview data on whereabouts and dietary habits collected during baseline screening in 1996-2001 (N=11,970; median age 21 years). Thyroid volume was estimated from thyroid ultrasound measurements during screening. Individuals with diagnoses of benign or malignant tumors of thyroid gland, any thyroid surgery or aplasia, and missing thyroid volume measurements were excluded (n=1,104). Dose and thyroid volume were log-transformed due to right-skewed distributions. We used a multivariable linear regression to estimate the dose-response association between 131I dose to the thyroid and thyroid volume accounting for confounding effects of sex, age at screening, and place of residence at the time of screening, a proxy for endemic iodine deficiency. To examine nonlinear effects, we added a quadratic term for the log-transformed dose. Among 10,866 participants, dose to thyroid ranged from 0.0005 to 39 gray (Gy) (median=0.3 Gy). In a linear regression model adjusted for confounders, log thyroid volume was best described by a linear-quadratic function of log dose (p<0.001 for log dose and log dose-squared coefficients). The largest effect was observed for doses 0.3-0.6 Gy (14%), then gradually decreased. Subjects with thyroid dose of 1 Gy had an average thyroid volume 13.6% (95% CI 8- 19.2%) higher compared to those with dose 1 mGy. Thyroid volume increased with age and was significantly higher for males compared to females and for those from Minsk city and area compared to other regions (both p<0.001). The adjusted R2-value was 30%, suggesting unaccounted factors that might better explain this association. This is the first study to assess the dose-response association between exposure to 131I and thyroid volume. Although statistically significant, the observed increase in thyroid volume with dose was small. Availability of measurements of iodine deficiency and dietary habits around the time of an accident in the future studies of nuclear accidents will be essential for understanding the mechanism of association between radiation dose and thyroid volume in young people.

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Effect of change in neck position on thyroid dose and volume in supraclavicular irradiation for breast cancer using conformal technique

Journal of Radiotherapy in Practice ◽

10.1017/s1460396920001144 ◽

2021 ◽

pp. 1-5

Author(s):

Sajeev George Pulickal ◽

Nikhil Sebastian ◽

Reshma Bhaskaran ◽

P Aparna

Keyword(s):

Breast Cancer ◽

Thyroid Gland ◽

Radiation Dose ◽

Thyroid Volume ◽

Contralateral Side ◽

Neck Position ◽

Significant Difference ◽

Thyroid Dose ◽

Radiation Planning

Abstract Background and aim: Radiation exposure to the thyroid gland during breast irradiation can lead to hypothyroidism and this can impact on the quality of life. The aim of this study was to analyse if there is any difference in the radiation dose received by the thyroid gland during supraclavicular irradiation for breast cancer, with two different neck positions—straight or when the head is turned to the contralateral side to the breast being treated, when using a conformal technique. Materials and methods: All patients who received chest wall/breast and supraclavicular irradiation for breast cancer in 2019 in our department were divided into two groups based on the neck position as SN (neck positioned straight) and TN (neck tilted to contralateral side). The volume of thyroid gland, the radiation dose and volume parameters for Dmax, Dmean, and V5 to V40 of the thyroid were tabulated. Results: There were 72 patients included in the study with a mean age of 59 years, with 39 in the SN group and 33 in the TN group. There was no significant difference in thyroid volume between the two groups. Dmean, V15, V20, V25, V30 and V35 were significantly lower in tilted neck patients as compared to straight neck patients. Conclusion: Neck positioned to the contralateral side of the breast primary may be recommended for conformal CT-based radiation planning.

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The Effect of Carbimazole Following Radioiodine Therapy on Radiation Dose to the Thyroid

Nuklearmedizin ◽

10.1055/s-0037-1620719 ◽

1981 ◽

Vol 20 (02) ◽

pp. 72-75 ◽

Cited By ~ 1

Author(s):

R. Kocak ◽

R.G. Herbert ◽

C.R. Squire ◽

T.M.D. Gimlette

Keyword(s):

Thyroid Gland ◽

Radiation Dose ◽

Half Life ◽

Radioiodine Therapy

Radioiodine in the thyroid gland after a therapy dose of 131I was measured serially in 7 patients without Carbimazole, and in 11 patients starting Carbimazole 60 mg daily fourteen days after the therapy dose. Effective half-life for radioiodine in the gland initially 5.53±1.08 days fell to 4.26±1.12 days (p < 0.01) during Carbimazole, and returned to 5.83±1.21 days (NS) after stopping the drug. The radiation dose to the thyroid from a given therapy dose of 131I followed by Carbimazole was calculated to be 97% of that without Carbimazole when the drug was started after 14 days, and 90% and 75% when the drug was started after 7 days and 1 day respectively.

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The Measurement of Heparin and Other Therapeutic Sufphated Polysaccharides in Plasma, Serum and Urine

Thrombosis and Haemostasis ◽

10.1055/s-0038-1660086 ◽

1985 ◽

Vol 54 (03) ◽

pp. 630-634 ◽

Cited By ~ 19

Author(s):

J Dawes ◽

C V Prowse ◽

D D Pepper

Keyword(s):

Biological Fluids ◽

Anticoagulant Activity ◽

Dose Range ◽

Plasma Concentrations ◽

Heparin Therapy ◽

Competitive Binding Assay ◽

First Order Kinetics ◽

Activity Measurements ◽

Heparin Activity ◽

Dose Dependent

SummaryThe competitive binding assay described will specifically and accurately measure concentrations of administered heparin in biological fluids with a sensitivity of 60 ng ml-1. Neither endogenous glycosaminoglycans, nor plasma proteins such as ATIII and PF4 interfere in the assay. Semi-synthetic highly sulphated heparinoids and LMW heparin can also be measured. Using this assay heparin clearance followed simple first-order kinetics over the dose range 100-5,000 units, but the half-life was strongly dose-dependent. There was good correlation with heparin activity measurements by APTT and anti-Xa clotting assays. Plasma concentrations were measurable for at least 5 h following subcutaneous injection of 10,000 units of heparin. Excretion in the urine could be followed after all but the lowest intravenous dose. This assay, used in conjunction with measurements of heparin anticoagulant activity, will be valuable in the elucidation of mechanisms of action of heparin and the heparinoids, and in the assessment and management of problems related to heparin therapy.

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Compensated 131I-therapy of solitary autonomous thyroid nodules: effect on thyroid size and early hypothyroidism

Acta Endocrinologica ◽

10.1530/acta.0.1130226 ◽

1986 ◽

Vol 113 (2) ◽

pp. 226-232 ◽

Cited By ~ 35

Author(s):

Laszlo Hegedüs ◽

Dagmar Veiergang ◽

Steen Karstrup ◽

Jens Mølholm Hansen

Keyword(s):

Thyroid Gland ◽

Thyroid Function ◽

Thyroid Nodules ◽

Thyroid Volume ◽

131I Therapy ◽

Important Place ◽

Gland Volume ◽

Thyroid Gland Volume ◽

One Year ◽

Hyperthyroid Patients

Abstract. Thyroid function and thyroid gland volume, ultrasonically determined, were investigated in 27 hyperthyroid patients with solitary autonomous thyroid nodules before and during one year after 131I-treatment. Total thyroid volume decreased gradually from 40.9 ± 3.5 ml (mean ± sem) before treatment to 23.9 ± 1.8 ml (P < 0.001) at 3 months after 131I-treatment. No further change was observed. All but two patients received only one dose of 131I, and in spite of a significant decrease also of the non-adenoma side of the gland, none became hypothyroid. We conclude that 131I-therapy has an important place in the treatment of solitary autonomous thyroid nodules since all our patients became euthyroid within 3 months, only 2 of 27 patients needed more than one dose of 131I, no cases of hypothyroidism occurred, and thyroid volume was substantially decreased.

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Radiation Dose to the Thyroid Gland and Breast From Multidetector Computed Tomography of the Cervical Spine: Does Bismuth Shielding With and Without a Cervical Collar Reduce Dose?

Yearbook of Diagnostic Radiology ◽

10.1016/s0098-1672(10)79240-7 ◽

2011 ◽

Vol 2011 ◽

pp. 74-75

Author(s):

B.J. Manaster

Keyword(s):

Computed Tomography ◽

Cervical Spine ◽

Thyroid Gland ◽

Radiation Dose ◽

Multidetector Computed Tomography ◽

Cervical Collar ◽

Bismuth Shielding

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Standardized grey scale ultrasonography in Graves' disease: correlation to autoimmune activity

Acta Endocrinologica ◽

10.1530/eje.0.1410332 ◽

1999 ◽

pp. 332-336 ◽

Cited By ~ 39

Author(s):

U Schiemann ◽

R Gellner ◽

B Riemann ◽

G Schierbaum ◽

J Menzel ◽

...

Keyword(s):

Thyroid Gland ◽

Antithyroid Drug ◽

Thyroid Volume ◽

Control Group ◽

Graves Disease ◽

Laboratory Findings ◽

Grey Scale ◽

Antithyroid Drug Treatment ◽

Student’S T ◽

A Prospective Study

OBJECTIVE: Graves' disease leads to thyroid enlargement and to reduction of tissue echogenicity. Our purpose was to correlate grey scale ultrasonography of the thyroid gland with clinical and laboratory findings in patients with Graves' disease. DESIGN: Fifty-three patients with Graves'disease were included in our study, 100 euthyroid volunteers served as control group. Free thyroxine (FT(4)), TSH and TRAb (TSH receptor antibodies) values were measured and correlated with sonographic echogenicity of the thyroid gland. METHODS: All patients and control persons underwent ultrasonographical histogram analyses under standardized conditions. Mean densities of the thyroid tissues were determined in grey scales (GWE). RESULTS: Compared with controls with homogeneous thyroid lobes of normal size (25.6 +/- 2.0GWE, mean +/- S.D.) echogenicity in patients with Graves' disease was significantly lower (21.3 +/- 3. 3GWE, mean +/- S.D., P < 0.0001). Among the patients with Graves' disease significant differences of thyroid echo levels were revealed for patients with suppressed (20.4 +/- 3.1 GWE, mean +/- S.D., n=34) and normalized TSH values (22.5 +/- 3.6GWE, mean +/- S.D., n=19, P < 0.02). Significantly lower echogenicities were also measured in cases of persistent elevated TRAb levels (19.9 +/- 2.9GWE, mean +/- S.D., n=31) in comparison with normal TRAb levels (22.9 +/- 3.5 GWE, mean +/- S.D., n=22, P < 0.0015). No correlation could be verified between echogenicity and either still elevated or already normalized FT(4) values or the thyroid volume. In coincidence of hyperthyroidism and Graves' ophthalmopathy (19.7 +/- 3.5GWE, mean +/- S.D., n=23) significantly lower echogenicity was measured than in the absence of ophthalmological symptoms (22.3 +/- 3.3GWE, mean +/- S.D., n=30, P < 0.016). Patients needing active antithyroid drug treatment revealed significantly lower thyroid echogenicity (20.3 +/- 3.1 GWE, mean +/- S.D., n=40) than patients in remission (23.7 +/- 3.4 GWE, mean +/- S.D., n=13, P < 0.001). Statistical evaluation was carried out using Student's t-test. CONCLUSIONS: Standardized grey scale histogram analysis allows for supplementary judgements of thyroid function and degree of autoimmune activity in Graves' disease. Whether these values help to estimate the risk of recurrence of hyperthyroidism after withdrawal of antithyroid medication should be evaluated in a prospective study.

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Can Thyroid Ultrasonography Predict Substernal Extension or Tracheal Compression in Goiters?

Canadian Association of Radiologists Journal ◽

10.1016/j.carj.2018.07.007 ◽

2018 ◽

Vol 69 (4) ◽

pp. 422-429

Author(s):

Hedyeh Ziai ◽

Nicole L. Lebo ◽

Ania Z. Kielar ◽

Michael J. Odell

Keyword(s):

Thyroid Gland ◽

Characteristic Curve ◽

Area Under The Curve ◽

Thyroid Volume ◽

Classification Systems ◽

Tracheal Compression ◽

Gland Volume ◽

The Us ◽

Thyroid Gland Volume ◽

Preoperative Ct

Purpose To determine whether an ultrasonography (US)-defined thyroid volume can accurately predict substernal extension or tracheal narrowing. Methods After research ethics approval, we identified patients with thyroid nodules investigated with both US and computed tomography (CT). Reviewers assigned scores for both substernal extension and tracheal compression on CT using pre-established classification systems. Statistical analysis with receiver operating characteristic curve analysis was performed to find the US-determined thyroid volume thresholds that correlated with each substernal extension and tracheal compression. Results This study included 120 patients (mean age 63.4 years; SD ± 15.9; 67% female). Thirty-five patients (29%) had substernal extension. The mean US total thyroid gland volume in patients with and without substernal extension were 92.4 and 37.6 cm3, respectively ( P < .001). 86% of patients with substernal extension had tracheal narrowing vs. 27% of patients without substernal extension ( P < .0001). A cutoff dominant gland volume of ≥37.5 cm3 showed 83% sensitivity and 79% specificity for substernal extension (area under the curve [AUC] = 0.84). A total thyroid gland volume threshold of ≥37.8 cm3 showed 89% sensitivity and 87% specificity for any degree of tracheal narrowing (AUC = 0.90). Conclusions This study suggests that US volumes may be used as a predictor to identify those patients with thyroid enlargement who are most at risk of substernal extension and tracheal compression and who may benefit from preoperative CT imaging for optimal surgical and anesthetic planning.

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Background Levels and Radiation Dose Yield of o-Tyrosine in Chicken Meat

Journal of Food Protection ◽

10.4315/0362-028x-54.12.935 ◽

1991 ◽

Vol 54 (12) ◽

pp. 935-938 ◽

Cited By ~ 3

Author(s):

NOEMI CHUAQUI-OFFERMANNS ◽

TOM MCDOUGALL

Keyword(s):

Radiation Dose ◽

Dose Response ◽

Response Curve ◽

Dose Range ◽

Background Level ◽

Chicken Meat ◽

Dose Response Curve ◽

Poultry Meat ◽

Wet Weight ◽

The Mean

The measurement of o-tyrosine levels in poultry meat is a potential method for postirradiation dosimetry of poultry. The validity of using o-tyrosine for this purpose has not yet been established. As part of the validation process, the o-tyrosine content in unirradiated chicken meat, the radiation dose response curve, and the effects of postirradiation storage on o-tyrosine levels are examined. In 18 individual samples, the mean background level of o-tyrosine was 0.18 ± 0.11 ppm (wet weight, 70% moisture), and the most frequent background level (60% of the cases) was between 0.05 and 0.15 ppm (wet weight, 70% moisture). In pooled samples of 10 chickens, the mean background level was 0.12 ± 0.03 ppm (wet weight, 70% moisture). The levels were not significantly affected by storage at 5°C (7 d) or by freezing the sample. The radiation dose response curve was linear within the dose range studied (0 to 10 kGy), with a slope of 0.127 ± 0.003 ppm (wet weight)/kGy. Although there was some variation in the intercept (0.132 ± 0.013), the slope was the same in all samples tested. Postirradiation storage at either 4 or 8°C until spoilage did not affect the levels of o-tyrosine. These data indicate that o-tyrosine level may be useful for determining the absorbed dose in chicken meat gamma-irradiated to doses greater than 0.6 kGy. Further validation studies are continuing.

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