Preablation Stimulated Thyroglobulin/TSH Ratio as a Predictor of Successful I¹³¹Remnant Ablation in Patients with Differentiated Thyroid Cancer following Total Thyroidectomy

Table 1

Comparison of baseline characteristics of successful and unsuccessful ablation.

Characteristic	Successful ablation; % (𝑛)	Unsuccessful ablation; % (𝑛)	𝑃 value
Age
40 or less	44.4 (20)	53.3 (16)	0.45
More than 40	55.6 (25)	46.7 (14)
Gender
Male	42.2 (19)	43.3 (13)	0.924
Female	57.8 (26)	56.7 (17)
Histopathological types
Papillary carcinoma	91.9 (41)	90.0 (27)	0.871
Follicular carcinoma	8.9 (4)	10.0 (3)
Size of tumor
>4 cm	77.8 (35)	63.3 (19)	0.172
<4 cm	22.2 (10)	36.7 (11)
Capsular invasion
Yes	15.6 (7)	33.3 (10)	0.072
No	84.4 (38)	66.7 (20)
Pathological tumor stage
pT1	40 (18)	33.3 (10)	0.297
pT2	33.3 (15)	20.0 (6)
pT3	17.8 (8)	26.7 (8)
pT4	8.9 (4)	20.0 (6)
LN involvement
N1a	8.9 (4)	23.3 (7)	0.064
N1b	33.3 (15)	23.3 (7)
Nx	28.9 (13)	43.3 (13)
No	28.9 (13)	10.0 (3)
Distant metastasis
M0	95.6 (43)	86.7 (18)	0.170
M1	2 (4.4)	13.3 (4)
TNM stage
Stage 1	75.6 (34)	53.3 (16)	0.061
Stage 2	2.2 (1)	6.7 (2)
Stage 3	8.9 (4)	3.3 (1)
Stage 4	13.3 (6)	36.7 (11)
ETA risk
Low risk	42.2 (19)	27.6 (8)	0.168
Intermediate risk	11.1 (5)	6.7 (2)
High risk	46.7 (21)	66.7 (20)
RAI dose
30–100 mCi	75.5 (34)	70 (21)	0.094
150 mCi	24.4 (11)	20 (6)
200 mCi	0	10 (3)
sTg
Median (IQR)	3.05 (0.20–14.5)	140 (17.65–689)	<0.001
Preablation sTg
≤18 ng	75.6 (34)	23.3 (7)	<0.001
>18 ng	24.4 (11)	76.6 (23)
TG/TSH
Median (IQR)	0.067 (0.005–0.26)	2.84 (0.366–22.61)	<0.001
sTg/TSH
≤0.35	79.5 (35)	20 (6)	<0.001
>0.35	20.5 (9)	80 (24)