The Effect of Thyroid Hormone Withdrawal, Performed to Evaluate the Success of I-131 Ablation, On Quality of Life in Female Patients With Low-Risk Differentiated Thyroid Cancer

Objective: There is a need to evaluate the treatment response in patients who have undergone radioiodine treatment (RIT) for differentiated thyroid cancerDiagnostic tests that are used for this purpose include radioiodine whole body scan (sWBS) and serum thyroglobulin (Tg) measurement which are most accurate during thyroid-stimulating hormone (TSH) stimulation. However temporary discontinuation of thyroid hormone therapy to increase TSH (withdrawal) may be associated with the morbidity of hypothyroidism The aim of our study was to show the effects of thyroid hormone withdrawal (THW), on quality of life and psychological symptoms in female patients with low-risk, well-differentiated papillary thyroid cancer. Methods: We applied the short form-36 (SF-36) and Symptom Checklist-90-R (SCL-90-R) questionnaires to the patients in the euthyroid state who were referred a median of 9 months (6-13 months) after RIT, to perform a dWBS and to evaluate stimulated Tg. We applied the same questionnaire again when thyroid-stimulating hormone (TSH) was > 30 μIU/mL 4 weeks after THW (hypothyroid state). We evaluated the changes in questionnaire scores using the paired-samples t test or the Wilcoxon signed rank test. Results: Our study included 52 patients (median age 48 years, range 23-65 years) with differentiated cancer. Forthy –two (%) of these patients received 3700 MBq I-131 wheras 7 (%) patients received 1850 MBq. . Ablation success based on the dWBS only was 96.2%, based on Tg only was 98% and based on thyroglobulin antibodies (TgAb) only was 88.5%. There was statistically significant worsening in anxiety, psychosis, additional items and general symptom index symptoms with the SCL-90-R questionnaire, and physical functioning, role limitation due to physical health, energy/fatigue, emotional well-being, social function, general health and health change with the SF-36 questionnaire. Conclusions: THW worsened the patients’ psychological symptoms and quality of life. Our findings show that stimulated Tg and the dWBS may have side effects that outweigh benefits in patients with low-risk differentiated thyroid cancer without TgAb interference and access to ultrasonography.