Table 1. Comparisons of characteristics of the patients.
| Factors | Unsuccessful outcome [Case number (%)] | Successful outcome [Case number (%)] | Statistics | P values |
|---|---|---|---|---|
| Age | ||||
| <45 | 80(40.61%) | 39(33.05%) | X2 = 1.794 | 0.180 |
| ≥45 | 117(59.39%) | 79(66.95%) | ||
| Gender | ||||
| Male | 53(26.90%) | 23(19.49%) | X2 = 2.215 | 0.137 |
| Female | 144(73.10%) | 95(80.51%) | ||
| Size of tumor | ||||
| ≤1cm | 39(19.80%) | 36(30.51%) | X2 = 4.668 | 0.031 |
| >1 cm | 158(80.20%) | 82(69.49%) | ||
| Pathology | ||||
| Papillary thyroid cancer | 192(97.46%) | 118(100.00%) | Fisher exact test | 0.161 |
| Follicular thyroid cancer | 5(2.54%) | 0(0.00%) | ||
| Capsular invasion | ||||
| No | 113(57.36%) | 79(66.95%) | X2 = 2.851 | 0.091 |
| Yes | 84(42.64%) | 39(33.05%) | ||
| Pathological tumor stage | ||||
| T1 | 65(32.99%) | 59(50.00%) | X2 = 13.193 | 0.004 |
| T2 | 32(16.24%) | 19(16.10%) | ||
| T3 | 87(44.16%) | 39(33.05%) | ||
| T4 | 13(6.60%) | 1(0.85%) | ||
| LN* metastasis | ||||
| N0 | 70(35.53%) | 62(52.54%) | X2 = 18.192 | <0.001 |
| N1a | 73(37.06%) | 46(38.98%) | ||
| N1b | 54(27.41%) | 10(8.47%) | ||
| Distant metastasis | ||||
| M0 | 183(92.89%) | 118(100.00%) | Fisher exact test | 0.001 |
| M1 | 14(7.11%) | 0(0.00%) | ||
| TNM* stage | ||||
| Stage I | 100(50.76%) | 63(53.39%) | X2 = 4.468 | 0.215 |
| Stage II | 12(6.09%) | 8(6.78%) | ||
| Stage III | 50(25.38%) | 36(30.51%) | ||
| Stage IV | 35(17.77%) | 11(9.32%) | ||
| ATA risks* | ||||
| Low risk | 57(28.93%) | 55(46.61%) | X2 = 17.453 | <0.001 |
| Intermediate risk | 119(60.41%) | 62(52.54%) | ||
| High risk | 21(10.66%) | 1(0.85%) | ||
| Time interval of surgery and 131I therapy | ||||
| <3 months | 165(83.76%) | 100(84.75%) | X2 = 0.054 | 0.816 |
| ≥3 months | 32(16.24%) | 18(15.25%) | ||
| Pre-ablation Tg* (ng/ml) | 38.40 ± 72.91 | 2.50 ± 3.29 | t’ = 6.900 | <0.001 |
| Pre-ablation TSH* (uIU/ml) | 91.98 ± 42.89 | 107.18 ± 36.11 | t’ = −3.367 | 0.001 |
*LN = lymph node, TNM stage = American Joint Committee on Cancer tumor-node-metastasis staging system, ATA risks = American Thyroid Association risks, Tg = thyroglobulin, TSH = thyroid stimulating hormone.