Prognostic implications of microscopic involvement of surgical resection margin in patients with differentiated papillary thyroid cancer after high-dose radioactive iodine ablation

Objective To evaluate the relationship between microscopic cancerous involvement of surgical margin and recurrence in patients with differentiated papillary thyroid cancer (PTC) who underwent total thyroidectomy followed by high-dose radioactive iodine ablation (HDRIA). Methods Consecutive 197 PTC patients (184 women; mean age 44.9 years) who underwent total thyroidectomy without gross residual tumor followed by HDRIA were retrospectively reviewed. Resection margin involvement was evaluated and recurrence of the disease was assessed with clinicopathologically. Recurrence detected within 12 months after HDRIA were defined as early recurrence, detected after 12 months were defined as late recurrence. Results The mean follow-up was 85.9 ± 16.6 months. Twelve patients (6.1%) had microscopic cancerous involvement of surgical margin [margin (+) group], and 185 patients had negative surgical resection margins [margin (−) group]. Three patients (25.0%) in the margin (+) group and 11 patients (5.9%) in the margin (−) group had early recurrence. Margin (+) group showed higher incidence of early recurrence and lower incidence of disease free compared to margin (−) group (25.0 vs. 5.9%, p