Endocrine Abstracts

Radioactive iodide (¹³¹I) is an effective treatment modality for papillary and follicular thyroid carcinomas. This retrospective study analyzed the role of ¹³¹I therapy in high-risk papillary thyroid carcinoma patients after surgical thyroid removal.

Methods: The study analyzed 1055 consecutive high-risk papillary thyroid cancer patients, including 825 females and 230 males who underwent near-total or total thyroidectomy and follow up at one Medical Center in Taiwan. Patients were categorized into four groups according to treatment outcome. Group A included disease-free patients defined as those with negative ¹³¹I whole body scan and lacking serum thyroglobulin (Tg), Tg antibody and recurrence. Group B included non-relapse patients defined as those with no clinical evidence of persistent or recurrent thyroid cancer. Group C included patients with persistent disease defined as those with cancer tissue persisting after surgery. Group D included patients suffering recurrence defined as cancer recurrence after surgery and ¹³¹I ablation.

Results: After a mean follow-up period of 10.1±5.4 years (median: 9.5 years), forty-six (4.36%) patients died of thyroid cancer. Nine group A cases with persistent or recurrent cancer were treated until achieving disease-free status. Group C patients received the highest ¹³¹I dose but had 25.7% mortality rate. In group D, four of fifty-six (7.1%) patients with recurrent local neck cancer died of thyroid cancer. Conversely, twelve of fifty-six (21.4%) cases died of thyroid cancer with distant metastases.

Conclusions: Radioactive iodide effectively controlled papillary thyroid carcinoma after thyroid ablation in 23.9% of high-risk patients. After surgery and ¹³¹I treatments most cases of persistent or recurrent local-regional neck cancer were effectively controlled in a relapse-free status with a cancer mortality rate of 19.0%.