| RR-DTC | Non-RR-DTC | P-value |
---|---|---|---|
223 | 181 | ||
Sex (male/female) | 70/153 | 50/131 | 0.410 |
Age (mean ± SD, years) | 48.79 ± 13.93 | 43.49 ± 11.88 | 0.001* |
 ≥ 48/ < 48 | 129/94 | 67/114 | 0.001* |
Operation frequency (once/two or more) | 162/61 | 159/22 | 0.001* |
Histological subtype (PTC/FTC/Mixed) | 208/6/8 | 179/2/0 | 0.722 |
Recurrence risk group (low, medium/high risk) | 26/197 | 24/157 | 0.627 |
Extrathyroidal extension (no/pathological/intraoperative/both) | 117/39/40/27 | 113/28/26/14 | 0.203 |
Autoimmune thyroid disease (no/yes) | 187/36 | 133/48 | 0.011* |
Tumor diameter (mean ± SD, mm) | 2.08 ± 1.58 | 1.68 ± 1.26 | 0.007* |
 ≥ 18.5/ < 18.5 | 114/109 | 57/124 | 0.001* |
Multi-focality (no/yes) | 95/128 | 79/102 | 0.833 |
Site of lymph node metastasis (no/central/lateral neck region/both) | 22/42/23/136 | 13/49/16/103 | 0.230 |
Numbers of lymph node metastasis (mean ± SD, number) | 9.20 ± 8.16 | 9.02 ± 8.33 | 0.832 |
Proportion of lymph node metastasis (mean ± SD, %) | 37.07 ± 0.27 | 40.05 ± 0.27 | 0.265 |
Locally advanced (no/yes) | 190/33 | 164/17 | 0.103 |
Clinical stage (I/II/III/IVA/IVB) | 110/63/7/0/43 | 135/31/10/2/3 | 0.001* |
Recurrence between the operation and iodine-131 treatment (no/yes) | 167/56 | 161/20 | 0.001* |
Time from the first operation to the first iodine-131 treatment (mean ± SD, months) | 25.93 ± 56.64 | 8.90 ± 22.66 | 0.001* |
 ≥ 16/ < 16 | 52/171 | 16/165 | 0.001* |
Site of metastasis | Â | Â | Â |
(single-site/multi-partial metastases) | 143/80 | 170/11 | 0.001* |
(local/distant metastases) | 133/90 | 155/26 | 0.001* |
Uptake of 131I (negative/positive) | 123/100 | 92/89 | 0.386 |
Uptake of 18F-FDG (negative/positive) | 61/162 | 170/11 | 0.001* |