scholarly journals Whole-Body Radioiodine Effective Half-Life in Patients with Differentiated Thyroid Cancer

Diagnostics ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1740
Author(s):  
Michele Klain ◽  
Carmela Nappi ◽  
Marina De Risi ◽  
Leandra Piscopo ◽  
Fabio Volpe ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Half Life ◽  
Differentiated Thyroid Cancer ◽  
Multivariable Analysis ◽  
Whole Body ◽  
131I Therapy ◽  
Retention Data ◽  
Remnant Ablation ◽  
131I Treatment ◽  
Body Retention

Background: Radioactive 131I (RAI) therapy is used in patients with differentiated thyroid cancer (DTC) after total thyroidectomy for remnant ablation, adjuvant treatment or treatment of persistent disease. 131I retention data, which are used to indicate the time at which a 131I treated DTC patient can be released from the hospital, may bring some insights regarding clinical factors that prolong the length of hospitalization. The aim of this study was to investigate the 131I whole-body retention in DTC patients during 131I therapy. Methods: We monitored 166 DTC patients to follow the 131I whole-body retention during 131I therapy with a radioactivity detector fixed on the ceiling of each protected room. A linear regression fit permitted us to estimate the whole-body 131I effective half-life in each patient, and a relationship was sought between patients’ clinical characteristics and whole-body effective 131I half-life. Results: The effective 131I half-life ranged from 4.08 to 56.4 h. At multivariable analysis, longer effective 131I half-life was related to older age and extensive extra-thyroid disease. Conclusions: 131I effective half-life during 131I treatment in DTC patients is highly variable among patients and is significantly longer in older and in patients with RAI uptake in large thyroid remnants or in extrathyroidal disease that significantly prolongs the whole-body retention of 131I.

Procedure guidelines for radioiodine therapy of differentiated thyroid cancer (version 3)

2007 ◽  
Vol 46 (05) ◽  
pp. 213-219 ◽  
Author(s):  
J. Dressler ◽  
W. Eschner ◽  
F. Grünwald ◽  
M. Lassmann ◽  
B. Leisner ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Differentiated Thyroid Cancer ◽  
Radioiodine Therapy ◽  
Differentiated Thyroid Carcinoma ◽  
Whole Body ◽  
131I Therapy ◽  
131I Ablation ◽  
Procedure Guidelines ◽  
Lower Blood ◽  
Higher Sensitivity

SummaryThe procedure guideline for radioiodine therapy (RIT) of differentiated thyroid cancer (version 3) is the counterpart to the procedure guideline for 131I whole-body scintigraphy (version 3) and specify the interdisciplinary guideline for thyroid cancer of the Deutsche Krebsgesellschaft concerning the nuclear medicine part. Recommendation for ablative 131I therapy is given for all differentiated thyroid carcinoma (DTC) >1 cm. Regarding DTC ≤1 cm 131I ablation may be helpful in an individual constellation. Preparation for 131I ablation requires low iodine diet for two weeks and TSHstimulation by withdrawal of thyroid hormone medication or by use of recombinant human TSH (rhTSH). The advantages of rhTSH (no symptoms of hypothyroidism, lower blood activity) and the advantages of endogenous TSHstimulation (necessary for 131I-therapy in patients with metastases, higher sensitivity of 131I whole-body scan) are discussed. In most centers standard activities are used for 131I ablation. If pretherapeutic dosimetry is planned, the diagnostic administration of 131I should not exceed 1–10 MBq, alternative tracers are 123I or 124I. The recommendations for contraception and family planning are harmonized with the recommendation of ATA and ETA. Regarding the best possible protection of salivary glands the evidence is insufficient to recommend a specific setting. To minimize the risk of dental caries due to xerostomia patients should use preventive strategies for dental hygiene.

scholarly journals Undetectable thyroglobulin makes 123I whole-body scan and stimulated thyroglobulin obsolete in follow-up care of differentiated thyroid cancer: a retrospective study

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Bastiaan Sol ◽  
Bert Bravenboer ◽  
Brigitte Velkeniers ◽  
Steven Raeymaeckers ◽  
Marleen Keyaerts ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Total Thyroidectomy ◽  
Differentiated Thyroid Cancer ◽  
Whole Body ◽  
Whole Body Scan ◽  
Body Scan ◽  
Remnant Ablation ◽  
Follow Up Care ◽  
Prognostic Utility

Abstract Background Differentiated thyroid cancer (DTC) is a common malignancy with increasing incidence. Follow-up care for DTC includes thyroglobulin (Tg) measurement and ultrasound (US) of the neck, combined with 131I remnant ablation when indicated. Diagnostic precision has evolved with the introduction of the new high-sensitive Tg-assays (sensitivity ≤0.1 ng/mL). The aim of the study was to determine the prognostic utility of high-sensitive Tg and the need for other diagnostic tests in DTC. Methods This was a retrospective, observational study. Patients with pathologically confirmed DTC, treated with total thyroidectomy and 131I remnant ablation, who had their complete follow-up care in our institution were selected (October 2013–December 2018). Subjects with possible thyroglobulin autoantibody interference were excluded. Statistical analysis was performed using the IBM SPSS® Statistics 24 software package. Results Forty patients were eligible for analysis. A total of 24 out of the 40 patients (60%) had an undetectable high-sensitive Tg 6 months after total thyroidectomy. None of these patients had a stimulated Tg above 1 ng/mL, or remnant on the 123I Whole-Body Scan (WBS) after 1 year of follow-up. Ultrasound of the neck, performed between 6 and 12 months postoperative, was negative in 21 out of the 24 patients. Conclusions This study shows that an undetectable high-sensitive Tg can change the management of patients with DTC and decrease the use and need of stimulated Tg and 123I WBS.

123I Scan With Whole-Body Retention Measurement at 48 Hours for Simplified Dosimetry Before 131I Treatment of Metastatic Thyroid Cancer

2020 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Jolanta M. Durski ◽  
Carrie B. Hruska ◽  
Trond V. Bogsrud ◽  
Mabel Ryder ◽  
Geoffrey B. Johnson
Keyword(s):  
Thyroid Cancer ◽  
Whole Body ◽  
131I Treatment ◽  
Body Retention ◽  
Metastatic Thyroid Cancer

A Slow Component of Iodine Turnover in Athyreotic Individuals

1977 ◽  
Vol 53 (1) ◽  
pp. 81-86
Author(s):  
T. Smith ◽  
C. J. Edmonds
Keyword(s):  
Half Life ◽  
Slow Component ◽  
Biological Significance ◽  
Test Dose ◽  
Whole Body ◽  
131I Treatment ◽  
Body Tissues ◽  
Body Retention ◽  
Extractable Fraction ◽  
Slow Turnover

1. Whole-body retention and plasma values of 131I after a test dose were measured for up to 32 days in patients previously rendered athyreotic by surgery and 131I treatment for thyroid carcinoma, and who were without detectable functioning tissue at the time of study. 2. About 99·8% of the administered 131I was rapidly excreted, consistent with renal iodide excretion. The remainder (about 0·2%) was eliminated slowly, with mean half-life 15 days; we call this the slow-turnover component. 3. By the sixth day after the 131I dose, very little [131I]iodide remained in the plasma. The average protein-bound 131I was only 0·0035% of dose/l, with mean half-life 14·1 days; 90% was non-extractable in butanol. Labelled albumin accounted for about 80% of the non-extractable fraction. 4. The distribution space estimated from the slow-turnover component and protein-bound 131I was 34 1, indicating that most of the slow-turnover component is extravascular. 5. Stable potassium iodide administration, starting 2 days after giving 131I, had no observable effect on the variables measured. 6. Impairment of renal function delayed [131I]iodide excretion and increased both slow-turnover component and plasma protein-bound 131I. 7. A simple model describing iodine kinetics in athyreotic individuals is suggested. It predicts that the slow-turnover component contains only about 4 μg of iodine and, since this is distributed widely in body tissues, it is unlikely to be of biological significance.

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