Abstract

To evaluate the effects of hypothyroidism on the quality of life of differentiated thyroid carcinoma patients undergoing postoperative iodine-131 (I131) therapy. A total of 140 thyroid carcinoma inpatients treated in our hospital from January 2016 to June 2017 were collected. All patients were treated with postoperative I131 therapy, and followed up for 3 years. The effect of I131 therapy on hypothyroidism was observed from the perspectives of gender, age, course of disease and I131. On this basis, multivariate logistic regression analysis was performed to screen the influencing factors for hypothyroidism in differentiated thyroid carcinoma patients undergoing postoperative I131 therapy, and the predictive model was established. Quality of life of patients was compared before and after I131 therapy, and the correlation between thyroid function indices and quality of life was further analyzed. The predictive value of I131 therapy after differentiated thyroid carcinoma surgery for the levels of thyroid function indices and quality of life was evaluated using receiver operating characteristic curve. A total of 140 patients undergoing I131 therapy after differentiated thyroid carcinoma surgery were enrolled. It was found through follow-up that the incidence rate of hypothyroidism was 35.00 % (49/140). The incidence of hypothyroidism after I131 therapy was related to the thyroid quality, course of disease, cumulative dose of I131 and operation method (p<0.01), but not related with gender, age or pathological type (p>0.05). The forest plot of multivariate logistic regression analysis results showed that thyroid quality, course of disease, I131 dose and operation method were independent risk factors for hypothyroidism after postoperative I131 therapy. Compared with before I131 therapy, each index of quality of life was significantly increased in differentiated thyroid carcinoma patients after postoperative I131 therapy (p<0.05). The results of correlation analysis revealed that some indices of quality of life (physical function, bodily pain, social function and mental health) were all positively correlated with thyroid function indices total triiodothyronine, free triiodothyronine, free thyroxine, total thyroxine and thyroid stimulating hormone (p<0.05 or p<0.01). Other indices of quality of life (role physical, general health, vitality and role emotional) had no significant correlations with triiodothyronine, free triiodothyronine, free thyroxine, total thyroxine or thyroid stimulating hormone (p>0.05). The area under receiver operating characteristic curve of thyroid stimulating hormone level in differentiated thyroid carcinoma patients was 0.819 (95 % CI: 0.744-0.893), and the optimal cutoff value was 0.63 mU/L. The cutoff value of I131 dose was 7.35 GBq, and the area under receiver operating characteristic curve was 0.726 (95 % CI: 0.623-0.830). Hypothyroidism in differentiated thyroid carcinoma patients undergoing postoperative I131 therapy has a significant impact on quality of life. There are correlations between indices of quality of life and thyroid function indices. Postoperative I131 therapy not only mitigates the symptoms of hypothyroidism, but also improves the overall quality of life of patientsr.