Efficacy of postoperative radioactive iodine therapy for patients with low and intermediate risk papillary thyroid carcinoma.

PURPOSE

This study aimed to evaluate the efficacy of postoperative radioactive iodine (RAI) and its impact on recurrence rates and survival benefits in low- to intermediate-risk papillary thyroid carcinoma (PTC).

METHODS

This retrospective study involved the examination of 1286 patients diagnosed with low- to intermediate-risk PTC who underwent total thyroidectomy with or without neck dissection, supplemented with postoperative RAI therapy or not between the years 2000 and 2021.

RESULTS

From the patient pool, 589 (45%) were classified as low-risk and 697 (55%) as intermediate-risk according to the 2015 American Thyroid Association guidelines. Among the low-risk group, 375 (63.7%) underwent postoperative RAI, while in the intermediate-risk group, 566 (82.2%) underwent the procedure. The overall survival and disease-free survival rates were not statistically different between the groups that received RAI and those that did not, in both the low- and intermediate-risk categories. In a subgroup analysis, within the intermediate-risk category, postoperative RAI was significantly correlated with decreased recurrence in two subgroups: patients over 55 years with pN1b disease (hazard ratio 0.043, 95% confidence interval 0.004-0.500, p = 0.012) and patients over 55 years with five or more metastatic lymph nodes (hazard ratio 0.060, 95% confidence interval 0.005-0.675, p = 0.023).

CONCLUSION

Our findings suggest that, while post-total thyroidectomy RAI does not substantially influence recurrence or survival rates in most low-risk and intermediate-risk PTC patients, it may be beneficial in specific subgroups, particularly patients over 55 with pN1b disease or those presenting with five or more metastatic lymph nodes.