Results from National Cancer Database and SEER Database with Outcome Measures for Radioiodine Therapy Versus No Radioiodine Therapy in DTC Patients at Low or Intermediate Risk (18,20,22)
| Database | Outcome measure | Patients (n) | RAI treatment | No RAI treatment | Interpretation |
| National Cancer Database (18) | OS | 61,777 (59% with T1b); 35,921 with RAI | HR, 0.77 (PTC, 1.0–2.0 cm); 95% CI, 0.68–0.87 | Compromised OS | Better OS with RAI in PTC T1b |
| National Cancer Database (18) | OS | 61,777 (41% with T2) 35,921 with RAI | HR, 0.86 (PTC, 2.1–4.0 cm); 95% CI, 0.76–0.98 | Compromised OS | Better OS with RAI in PTC T2 |
| SEER Database (20) | OS | 61,049 | HR, 1.0 as reference for age < 45 y, male, white, T2 N0 M0 | HR, 1.3; 95% CI, 1.1–1.5; P = 0.002 | Compromised OS without RAI vs. low-risk patients with RAI |
| National Cancer Database (22) | OS | 21,870 at intermediate risk with PTC T3 N0 M0 or T1–T3 N1 M0; 15,418 with RAI | HR, 0.71; 95% CI, 0.62–0.87; P < 0.01; multifocal, 51%; N1, 74%; R1, 19% | HR, 1.0 as reference; multifocal, 47%; N1, 68%; R1, 15% | Better OS with RAI despite more multifocal tumors, lymph node metastases, and R1 resections |
| National Cancer Database (22) | OS in patients < 45 y old | 12,612 | HR, 0.64; 95% CI, 0.45–0.92; P = 0.016 | HR, 1.0 as reference | Better OS with radioiodine also in younger group |
OS = overall survival; RAI = radioiodine.