|
Variable
|
Whole cohort N (%)
|
RAI ablation N (%)
|
Without RAI ablation N (%)
|
P value*
|
|---|
|
Total patients
|
326/1192 (27.4 %)
|
182/326 (55.8)
|
144/326 (44.2)
|
0.06
|
|
Age (years)
|
42.6 (18–76) SD ±11.6
|
43.2 (18–76) SD ± 12.4
|
41.8 (19–71) SD ± 10.2
| |
|
≤45 years
|
201 (61.7)
|
110 (60.4)
|
94 (65.3)
|
0.81
|
|
≥45 years
|
125 (38.3)
|
72 (39.6)
|
50 (34.7)
| |
|
Gender
|
|
Female
|
271 (83.1)
|
146 (80.2)
|
125 (86.8)
|
0.06
|
|
Male
|
55 (16.9)
|
36 (19.8)
|
19 (13.2)
| |
|
Female to male ratio
|
4.9
|
4.0
|
6.5
| |
|
Type of surgery
|
|
Total thyroidectomy
|
299 (91.7)
|
182 (100)
|
117 (81.3)
|
0.04
|
|
Hemi-thyroidectomy
|
27 (8.3)
|
-
|
27 (18.7)
| |
|
Lymph node surgery
|
|
Central neck dissection
|
88 (27.0)
|
54 (29.7)
|
34 (23.6)
| |
|
Lateral neck dissection
|
18 (5.5)
|
9 (4.9)
|
9 (6.3)
|
0.9
|
|
Sampling
|
55 (16.9)
|
25 (13.7)
|
30 (20.8)
| |
|
None
|
165 (50.6)
|
94 (51.7)
|
71 (49.3)
| |
|
Mean size (cm)
|
0.61 (0.1–1.0) ± 0.24
|
0.72 (0.2–1.0) ± 0.21
|
0.44 (0.1–0.9) ± 0.2
| |
|
≤0.5 cm
|
161 (49.4)
|
50 (27.5)
|
111 (77.1)
|
<0.0001
|
|
≥0.5 cm
|
165 (50.6)
|
132 (72.5)
|
33 (22.9)
| |
|
Histopathologic variants
|
|
Classic
|
265 (81.3)
|
143 (78.6)
|
122 (84.7)
| |
|
Follicular
|
41 (12.6)
|
21 (11.5)
|
20 (13.9)
| |
|
Hurthle cell
|
8 (2.5)
|
6 (3.3)
|
2 (1.4)
| |
|
Tall cell
|
11 (3.4)
|
11 (6.0)
|
-
|
0.001
|
|
Sclerosing
|
1 (0.3)
|
1 (0.5)
|
-
| |
|
Multifocal
|
|
Yes
|
125 (38.3)
|
122 (67.1)
|
3 (2.1)
|
<0.0001
|
|
No
|
201 (61.7)
|
60 (32.9)
|
141 (97.9)
| |
|
ETE
|
|
Yes
|
62 (19.0)
|
57 (31.3)
|
5 (3.5)
|
<0.0001
|
|
No
|
264 (81.0)
|
125 (68.7)
|
139 (96.5)
| |
|
LVSI
|
|
Yes
|
55 (16.9)
|
49 (26.9)
|
6 (4.2)
|
<0.0001
|
|
No
|
271 (83.1)
|
133 (73.1)
|
138 (95.8)
| |
|
Surgical margins
|
|
Positive
|
35 (10.7)
|
30 (16.5)
|
5 (3.5)
|
<0.0001
|
|
Negative
|
291 (89.3)
|
152 (83.5)
|
139 (96.5)
| |
|
Lymph node metastasis
|
|
Yes
|
42 (12.9)
|
42 (23.1)
|
-
|
<0.0001
|
|
N1a
|
34 (73.8)
|
34 (73.8)
| | |
|
N1b
|
8 (19.2)
|
8 (19.2)
| | |
|
No
|
284 (87.1)
|
140 (76.9)
|
144 (100)
| |
|
Background thyroid tissue
|
|
Normal
|
98 (30.1)
|
47 (25.8)
|
51 (35.4)
| |
|
Multi-nodular goiter
|
106 (32.5)
|
60 (32.9)
|
46 (31.9)
| |
|
Lymphocytic thyroiditis/Hashimotos’ thyroiditis
|
122 (37.5)
|
75 (41.3)
|
47 (32.6)
|
0.052
|
|
Distant Metastasis at presentation
|
3 (0.9)
|
3 (1.65)
|
-
|
<0.0001
|
|
AJCC staging
|
|
I
|
217 (66.5)
|
73 (40.1)
|
139 (96.5)
| |
|
II
|
-
|
-
|
-
| |
|
III
|
96 (29.5)
|
96 (52.6)
|
5 (3.5)
|
<0.0001
|
|
IVA
|
10 (3.1)
|
10 (5.6)
|
-
| |
|
IVB
|
-
|
-
|
-
| |
|
IVC
|
3 (0.9)
|
3 (1.7)
|
-
| |
|
Mean postoperative TG (ng/ml)
|
1.39 (0.1–42890)
|
2.44 (0.1–42890)
|
0.39 (0.1–8.9)
|
0.62
|
|
RAI dose
|
|
30 mCi
| |
50 (27.5)
|
-
|
<0.0001
|
|
100 mCi
| |
85 (46.7)
|
-
| |
|
150-200 mCi
| |
47 (25.8)
|
-
| |
|
RT to Neck
|
2 (0.61)
|
2 (1.1)
|
-
|
<0.0001
|
|
Recurrences
| | | | |
|
Locoregional
|
13 (3.9)
|
4 (2.2)
|
9 (6.2)
|
<0.001
|
|
Distant
|
10 (3.1)
|
4 (2.2)
|
6 (4.2)
| |
- *P value pertaining to the variation in clinicopathological characteristics between two groups
-
RAI radioactive iodine 131, N number, SD standard deviation, ETE extra-thyroidal extension, LVSI lymphovascular space invasion, AJCC American joint committee on cancer, TG thyroglobulin, mCi millicurie, RT radiation therapy
