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. 2018 Jan;19(1):239-242.
doi: 10.1002/acm2.12217. Epub 2017 Nov 22.

Reproducibility of radioactive iodine uptake (RAIU) measurements

Matthieu Pelletier-Galarneau  1 , Patrick Martineau  1 , Ran Klein  1 , Matthew Henderson  2 , Lionel S Zuckier  1
Affiliations

Reproducibility of radioactive iodine uptake (RAIU) measurements

Matthieu Pelletier-Galarneau et al. J Appl Clin Med Phys. 2018 Jan.

Abstract

Background: Measurement of radioactive iodine uptake (RAIU) is an important aspect of the assessment and treatment of patients with hyperthyroidism. Its uncertainty affects how much of a true change in RAIU can be detected as well as appropriateness of the therapy dosage upon which it is based. In this study, a method of estimating the reproducibility and least significant change (LSC) values for RAIU measurements, and the implications of the values observed are discussed, with emphasis on application to quality assurance initiatives.

Methods: We prospectively studied 36 consecutive patients referred for RAIU measurements. Twenty-four hours after oral administration of 370 kBq of 131 I-NaI in capsule form, RAIU measurements were obtained in duplicate using a thyroid probe uptake system. Assessment of reproducibility was performed using root-mean-square standard deviation.

Results: Average difference between duplicated RAIU measurements in our study cohort was -0.1 ± 1.6% and ranged from -4.8% to 3.1%. Reproducibility of probe-based RAIU measurement was calculated to be 1.1% and 95% LSC was 3.2%.

Conclusion: In our clinic, probe-based RAIU is a reproducible and relatively precise measurement. Using the method we have outlined, each institution can perform reproducibility assessment and compute the LSC of RAIU measurements based on its own staff, iodine isotope, equipment, protocols, and patient population. These values are useful in the assessment of serial change in RAIU, and as more experience is accumulated, can serve as benchmarks to be used in quality assurance initiatives.

Keywords: hyperthyroidism; radioiodine therapy; radioiodine thyroid uptake; reproducibility.

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Figures

Figure 1
Figure 1
Bland–Altman plot showing the reproducibility of duplicated radioactive iodine uptake (RAIU) measurements in 36 patients. Mean difference and 95% confidence interval of mean of difference is indicated by the solid and dotted lines respectively. Linear correlation of difference versus average of the duplicated RAIU value is indicated by the red line.
Figure 2
Figure 2
Absolute value of difference versus average of duplicated radioactive iodine uptake (RAIU) measurements in 36 patients.
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References

    1. Chapman EM, Maloof F. The use of radioactive iodine in the diagnosis and treatment of hyperthyroidism: ten years’ experience. Med (Baltimore). 1955;34:261–322. - PubMed
    1. Werner SC, Hamilton HB, Leifer E, et al. An appraisal of the radioiodine tracer technic as a clinical procedure in the diagnosis of the thyroid disorders; uptake measurement directly over the gland and a note on the use of thyrotropin (T.S.H.). J Clin Endocrinol Metab. 1950;10:1054–1076. - PubMed
    1. Bahn RS, Burch HB, Cooper DS, et al. Hyperthyroidism and other causes of thyrotoxicosis: management guidelines of the American Thyroid Association and American Association of Clinical Endocrinologists. Endocr Pract. 2011;17:456–520. - PubMed
    1. Chapman EM. History of the discovery and early use of radioactive iodine. JAMA. 1983;250:2042–2044. - PubMed
    1. Hamburger JI. Subacute thyroiditis: diagnostic difficulties and simple treatment. J Nucl Med. 1974;15:81–89. - PubMed

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