Analysis of the Efficacy of Low-Dose Iodine-131 in the Treatment of Differentiated Thyroid Cancer and Its Effects on Salivary Gland Function and Serum Markers

doi:10.3969/j.issn.1674-3245.2025.06.034

Abstract：Objective To analyze the role of low-dose iodine-131 in the ablation therapy of differentiated thyroid cancer, and to explore its efficacy and effects on salivary gland function indicators and serum markers. Methods This study conducted a retrospective analysis of 80 patients with differentiated thyroid cancer at Anhui CESTG Hospital from June 2021 to August 2024. All patients were treated with levothyroxine sodium and underwent iodine-131 ablation therapy. According to the iodine-131 dose (to ensure equal numbers in both groups, a matched group design was used), they were divided into a control group and an observation group, each with 40 cases. The control group received a conventional dose: 30–100 mCi (1.11–3.70 GBq); the observation group received a low dose: 30–50 mCi (1.11–1.85 GBq), both administered as a single oral dose. The total effective rate of treatment, salivary gland function, thyroid hormone levels, bone metabolism indicators, quality of life, and incidence of adverse drug reactions were compared between the two groups. Results The total effective rate of treatment in the observation group was 95.00%, which was higher than that of the control group (77.50%), with a statistically significant difference (χ2=6.165, P<0.05). After medication, the maximum radioactivity counts of the bilateral glands in the observation group were (96.54±17.15) cps and (95.24±16.32) cps, and the secretion indices after acid stimulation were (50.16±2.24)% and (50.44±1.80)%, respectively. Free thyroxine level was (28.27±8.97) pmol/L, free triiodothyronine level was (6.56±0.72) pmol/L, and quality of life score was (82.08±6.17) points, all higher than those in the control group (t=2.271, 2.250, 6.070, 5.792, 5.154, 12.750, 5.702, P<0.05). Thyroid-stimulating hormone level was (0.56±0.12) mIU/L, alanine aminotransferase (32.56±3.18) U/L, aspartate aminotransferase (34.78±3.21) U/L, alkaline phosphatase (88.72±9.64) U/L, thyroglobulin (1.16±0.18) μg/L, thyroglobulin antibody (1598.24±172.12) IU/mL, vascular endothelial growth factor (345.21±20.48) pg/mL, and macrophage inflammatory protein-1α (22.18±5.56) ng/L, all lower than those in the control group, with statistically significant differences (t=29.979, 16.496, 14.479, 7.912, 13.071, 9.031, 5.736, 9.063, P<0.05). Compared with the control group, the observation group had a lower incidence of adverse reactions, with a statistically significant difference (χ2=5.165, P<0.05). Conclusion Compared with conventional-dose iodine-131 ablation therapy, low-dose iodine-131 can effectively treat differentiated thyroid cancer, regulate thyroid hormone levels, have less impact on salivary gland function and bone metabolism indicators, and ensure medication safety while improving patients' quality of life.