The Factors correlated with discordance between thyroid volume measurement by palpation and ultrasound methods for radioiodine treatment in Graves’ disease

Abstract

Purpose: To evaluate the related factors of thyroid volume (TV) discordance between palpation (P-TV) and ultrasound (US-TV) methods and the TV’s cut-off point that separates the discordance and concordance groups.

Design: A retrospective study in patients with Graves’ disease (GD) who were referred for RAI treatment from January 2019 to September 2022.

Methods: In this retrospective study, we included 477 patients with Graves’ disease (GD) who were referred for radioiodine treatment from January 2019 to September 2022. The TVs of these patients were measured via P-TV and US-TV. The data were analyzed using one-way ANOVA, Chi-square, univariate regression, multivariate logistic regression, and linear regression analyses. We evaluated the cut-off point of the TV that separates the discordance and concordance groups. We also tested the accuracy of this cut-off value and reported the sensitivity, specificity, PPV, NPV, and accuracy. The threshold for statistical significance was set at p < 0.05.

Results: P-TV underestimation was positively correlated to smoking (aOR: 2.37; 95%CI: 1.16–4.84) and goiter symptoms (aOR: 2.42; 95%CI: 1.53–3.82). Regarding P-TV overestimation, there was only the pre-tracheal thickness that was negatively correlated (aOR: 0.82; 95%CI: 0.71–0.95). The cut-off point value of the TV was 30 grams with 91.21% sensitivity, 68.14% specificity, 63.85% PPV, 92.63% NPV, and 76.94% accuracy.

Conclusions: Smoking and goiter symptoms, as well as a thyroid volume of >30 grams, correlate with P-TV underestimation; thus, such patients should undergo ultrasonography.