MON-558 Radioiodine Is Not Associated with Quality of Life Outcomes in Early Stage Thyroid Cancer Survivors, a Matched-Pair Analysis.

Background: Radioiodine ablation (RAI) is often given as adjuvant therapy following thyroidectomy for differentiated thyroid cancer (DTC). The benefits of RAI are unclear in low-risk DTC, and the effects of RAI on health-related quality of life (HRQoL) are not well described. We hypothesized RAI would be associated with lower HRQoL in survivors of DTC. Methods: A matched-pair analysis was performed using DTC survivors >18 years of age recruited from a thyroid cancer support group. Demographics, clinical features, treatments and surgical complications were self-reported via online survey. Postoperative dysphonia and dysphagia, and post-RAI xerostomia and dysphagia were assessed using Likert scale. HRQoL was evaluated using PROMIS-29 domains of anxiety, depression, fatigue, pain, physical function, sleep disturbance, and social role function. Stage I respondents who received RAI were matched for age, sex, race, and years since diagnosis against those who did not receive RAI. PROMIS T-scores were compared between RAI and no RAI groups by univariate analysis and Wilcoxon rank-sum test. A mean T-score difference of 3 or more was considered clinically significant. Categorical outcomes were assessed via Fisher’s exact test, alpha set at 0.05. Results: 138 pairs were matched for extent of surgery, stage, age, sex, race, and years since diagnosis. Mean age was 43.7+/-11.6 and 44.8+/-10.9 years, and mean time since surgery was 2.6+/-2.6 and 2.7+/-2.5 years for RAI and no RAI groups, respectively. There was no difference in incidence of the surgical complications of hypocalcemia (p=0.76), infection (p=0.61), dysphonia (p=0.87), or dysphagia (p=0.74) between the RAI and no RAI groups. There was no significant difference between mean PROMIS T-scores in any PROMIS domains. In those respondents reporting normal preoperative voice and swallowing (86 pairs), the mean T-score in the pain domain in the RAI group (53.9+/-10.3 vs 49.8+/-10.5; p=0.009) was clinically and statistically significantly higher than the no RAI group. 9.3% reported chronic xerostomia and dysphagia that developed after RAI. Conclusions: This is the first study to use PROMIS measures to evaluate the association between RAI and HRQoL in early stage DTC. In a matched-pair analysis of DTC survivors with stage 1 disease, no statistically significant difference was identified in HRQoL between groups that did or did not receive RAI. In subset analysis of respondents who reported normal preoperative voice and swallowing, RAI was associated solely with worse scores in the PROMIS pain domain.​ Further investigation is needed to describe why patients treated with RAI experience more pain.