Higher adjuvant radioactive iodine therapy dosage helps intermediate-risk papillary thyroid carcinoma patients achieve better therapeutic effect

• Published in: Frontiers in endocrinology (Lausanne) Vol. 14; p. 1307325
• Main Authors: Li, Xue, Zheng, Hongyuan, Ma, Chao, Ji, Yanhui, Wang, Xuan, Sun, Danyang, Meng, Zhaowei, Zheng, Wei
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 17-01-2024
• Subjects: adjuvant radioactive iodine therapy; Carcinoma, Papillary - pathology; decision curve analysis (DCA); dosages; Endocrinology; Female; Humans; intermediate-risk papillary thyroid carcinoma; Iodine Radioisotopes - therapeutic use; Male; Retrospective Studies; therapy response; Thyroglobulin; Thyroid Cancer, Papillary - surgery; Thyroid Neoplasms - pathology; Thyroidectomy; Thyrotropin; decision curve analysis (DCA); adjuvant radioactive iodine therapy; intermediate-risk papillary thyroid carcinoma; therapy response; dosages
• ISSN: 1664-2392; 1664-2392
• DOI: 10.3389/fendo.2023.1307325

This retrospective study aims to evaluate the therapeutic effect of varying dosages of adjuvant radioactive iodine (RAI) therapy on intermediate-risk papillary thyroid carcinoma (PTC) patients.
This retrospective study involved a total of 427 intermediate-risk PTC patients, out of which 202 received a 3.7GBq dosage of RAI, and 225 received a 5.55GBq dosage. The evaluation involved assessing the therapeutic outcomes, number of treatment cycles, and successful remnant ablation rates in both dose groups, six months post-adjuvant RAI therapy. Univariate and multivariate logistic regression analyses were employed to identify factors linked with excellent response (ER). Following this, prognostic nomograms were constructed to provide a visual representation of the prediction models. Calibration curves, the concordance index (C-index), and the receiver operating characteristic (ROC) curve were employed to evaluate the predictive performance of these nomograms. The Hosmer-Lemeshow test was applied to assess the models' goodness-of-fit. Additionally, the clinical utility of the prognostic nomograms was appraised through decision curve analysis (DCA).
The high-dose (HD) group exhibited significantly higher proportions of ER, single treatment cycles, and successful remnant ablation rates (p<0.05). Being male, receiving a 3.7GBq dose, having an N1b stage, an sTg level ≥10ng/ml, or an sTg/TSH ratio ≥0.11 were independent risk factors for Non-ER. Two prognostic nomograms, "sTg Nomogram" and "sTg/TSH Nomogram", were established. The ranking of factors contributing to ER, in descending order, included the sTg or sTg/TSH ratio, N stage, therapy dosage, sex, and soft tissue invasion. The "sTg/TSH Nomogram" demonstrated a higher C-index compared to the "sTg Nomogram". The calibration curves indicated excellent calibration for both nomograms. DCA demonstrated that the net benefit of the "sTg/TSH Nomogram" was higher than that of the "sTg Nomogram".
Higher initial RAI therapy doses can improve therapeutic efficacy for intermediate-risk PTC patients. The developed nomograms, particularly the "sTg/TSH Nomogram", could assist clinicians in optimal therapeutic decision-making.