Influence of radioactive iodine therapy on liver function in patients with differentiated thyroid cancer

This study aimed to investigate the influence of radioactive iodine (RAI) therapy on liver function in patients with differentiated thyroid cancer (DTC), with emphasis on sex and dose accumulation.

Liver function after the first RAI ablation with ~3700 MBq (100 mCi) dosage was compared with baseline liver function in 357 patients with DTC (male: 110 and female: 247). Further comparisons were conducted in patients after regular and successive RAI therapies with available data, 126 patients (male: 37 and female: 89) with two RAI therapies, 52 patients (male: 16 and female: 36) with three RAI therapies, and 19 patients (male: 5 and female: 14) with four RAI therapies. Analyses were performed to evaluate the potential effect of RAI on liver function, including total protein (TP), albumin (ALB), globulin (GLO), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT), lactic dehydrogenase, total bilirubin (TBIL), and direct bilirubin (DBIL) in both sexes. Continuous variables were analyzed by using nonparametric analysis.

Compared with the original hepatic function, TP (P<0.01), ALB (P<0.05), GLO (P<0.01), ALT (P<0.05), ALP (P<0.01), and GGT (P<0.01) declined significantly after the first RAI ablation in both sexes. TP, GLO, and GGT declined significantly in both sex subgroups, whereas ALT (P<0.05), ALP (P<0.01), and lactate dehydrogenase (P<0.05) showed significant decline in male subgroup, and TBIL (P<0.05) in female subgroup. As to the level of liver function after the second RAI therapy, TP (P<0.01), GLO (P<0.01), ALP (P<0.01), GGT (P<0.01), and DBIL (P<0.05) showed a significant decreasing trend. In both sex subgroups, TP, GLO, and GGT reduced significantly. Moreover, only ALP (P<0.01) significantly decreased in the male subgroup. As to the level of liver function after the third RAI therapy session, TP (P<0.01) and GLO (P<0.01) reduced significantly, whereas DBIL (P<0.05) was higher than the original level. In sex subgroups, TP (P<0.05) decreased significantly in the male subgroup, and GLO (P<0.01) decreased significantly in the female subgroup, but DBIL (P<0.05) increased significantly in the female subgroup. As to the level of liver function after the fourth RAI therapy, TBIL (P<0.05) and DBIL (P<0.01) increased significantly. In sex subgroups, TBIL (P<0.05) and DBIL (2.09±0.92 vs. 2.91±1.14 μmol/l, P<0.05) showed an increasing trend in the female subgroup only.

Liver function of patients with DTC after the first RAI ablation decreased significantly, including TP, ALB, GLO, ALT, ALP, and GGT. However, after multiple and regular RAI therapies, TBIL and DBIL showed an increasing trend. Particularly, TBIL and DBIL showed an increasing trend in the female subgroup only.