Long-term thyroid outcomes and thiol–disulfide homeostasis in childhood Hodgkin lymphoma survivors treated with neck radiotherapy

Abstract Objectives To evaluate long-term thyroid outcomes and thiol–disulfide homeostasis (TDH) in childhood Hodgkin lymphoma (HL) survivors treated with neck radiotherapy (RT). Methods Forty consecutive childhood HL survivors and 40 healthy controls were included. Thyroid function, autoimmunity markers, and ultrasonographic findings were evaluated in survivors. Native thiol, total thiol, disulfide, and related ratios were assessed in both groups. Factors associated with subclinical hypothyroidism and thyroid nodules were analyzed. Results Survivors had a median age of 16.8 years (range, 5.1–33.2) and a median interval since RT of 4.6 years (range, 1.3–20.2). Seventeen survivors (42.5 %) had received >25 Gy neck RT. Subclinical hypothyroidism was identified in 18 survivors (45.0 %); 13 of these 18 (72.2 %) were receiving levothyroxine. Thyroid nodules were identified in seven survivors (17.5 %), with no thyroid malignancy detected. TDH parameters did not differ significantly between survivors and controls. In survivors, native thiol/total thiol and disulfide/total thiol ratios correlated significantly with free T4 and free T3 concentrations. Thyroid nodule presence was associated with longer time since RT (OR=1.354 per year). Conclusions Functional and structural thyroid abnormalities were frequent in childhood HL survivors treated with neck RT, supporting continued thyroid surveillance. Associations between TDH ratios and thyroid hormones in survivors remain exploratory and warrant evaluation in longitudinal studies.