Thyroid dysfunction following radiofrequency ablation for benign thyroid nodules: more likely to occur within one-week and in high-risk population

Figures & data

Figure 1. Flowchart of the study design. BTNs: benign thyroid nodules; RFA: radiofrequency ablation; FT3: free triiodothyronine; FT4: free thyroxine; TSH: thyrotropin.

Figure 2. (A) Ablation volume ratio = (ablation volume of nodule a + ablation volume of nodule b + ablation volume of nodule c)/total thyroid volume × 100%. (B) Initial ablation ratio = ablation volume of the nodule/total volume of the nodule × 100%. When the treated nodule achieves complete ablation, the initial ablation ratio is 100%.

Table 1. Baseline characteristics.

Variables	Results
Number of patients/nodules	75/114
Age (years)	41.31 ± 14.05
Sex (female/male)	60 (80.00%)/15 (20.00%)
Patients with hypertension	10 (13.33%)
Patients with diabetes	3 (4.00%)
Patients with previous thyroid surgeries
Partial thyroidectomy	5 (6.67%)
Unilateral near-total thyroidectomy	2 (2.67%)
TPOAb positive	13 (17.33%)
TgAb positive	17 (22.67%)
Number of ablated nodules of each patient (1/≥2)	49 (65.33%)/26 (34.67%)
Proportion of solidity
≥70%	57 (50.00%)
30–70%	16 (14.04%)
≤30%	41 (35.96%)
Location of nodule (left lobe /right lobe/isthmus)	45 (39.47%)/64 (56.14%)/5 (4.39%)

TPOAb: thyroid peroxidase antibody; TgAb: thyroglobulin antibody.

Data shown are expressed as means ± standard deviations or numbers (percentages).

Table 2. Treatment efficacy within 12 months after RFA.

Variables	Baseline	1 week	1 month	6 months	12 months
Maximum nodule diameter (mm)	26.00	27.00	23.00	14.00	11.00
	(16.25–40.00)	(18.00–35.00)	(15.00–30.00)*	(8.00–21.25)*	(7.00–19.50)*
Nodule volume (ml)	3.80	3.73	2.45	0.73	0.32
	(0.94–10.53)	(1.32–9.20)	(0.73–5.00)*	(0.07–1.97)*	(0.06–1.45)*
VRR (%)	–	−5.77	33.19	90.06	93.91
		(−68.06–28.31)	(5.09–57.24)	(67.16–96.71)	(75.74–99.05)
Cosmetic score	4.00	–	2.00	1.00	1.00
	(3.00–4.00)		(1.00–3.00)*	(1.00–2.00)*	(1.00–1.00)*

RFA: radiofrequency ablation; VRR: volume reduction ratio.

Data shown are medians (interquartile ranges, IQRs).

*p < 0.05 vs. respective baseline values.

Figure 3. Changes in FT3, FT4, and TSH before and after RFA. FT3: free triiodothyronine; FT4: free thyroxine; TSH: thyrotropin; RFA: radiofrequency ablation.

Figure 4. Incidence of different types of thyroid dysfunction within 12 months after RFA. RFA: radiofrequency ablation.

Table 3. Risk factors analysis of all types of thyroid dysfunction in 1 week–12 months after RFA.

Variables	Thyroid dysfunction group	Euthyroid group	Univariate logistic regression		Multivariate logistic regression
	(n = 35)	(n = 40)	OR (95%CI)	p-Value	OR (95%CI)	p-Value
Baseline characteristics
Age (years)	42.09 ± 15.15	40.63 ± 13.17	1.008 (0.975–1.041)	0.650	–	–
Sex (female/male）	31 (88.57%)/4 (11.43%)	29 (72.50%)/11 (27.50%)	0.340 (0.097–1.189)	0.091	–	–
Hypertension	7 (20.00%)	3 (7.50%)	3.083 (0.731–12.999)	0.125	–	–
Diabetes	2 (5.71%)	1 (2.50%)	2.364 (0.205–27.249)	0.490	–	–
Thyroidectomy	5 (14.29%)	2 (5.00%)	3.167 (0.574–17.478)	0.186	–	–
Baseline FT3 (pmol/L)	4.53 (4.19–4.97)	4.43 (4.06–4.77)	1.719 (0.655–4.512)	0.271	–	–
Baseline FT4 (pmol/L)	13.63 (12.66–14.44)	13.09 (12.12–14.59)	1.043 (0.851–1.279)	0.682	–	–
Baseline TSH (μIU/ml)	1.08 (0.67–1.52)	1.44 (1.11–2.15)	0.658 (0.374–1.158)	0.147	–	–
TPOAb positive	7 (20.00%)	6 (15.00%)	1.417 (0.427–4.702)	0.569	–	–
TgAb positive	10 (28.57%)	7 (17.50%)	1.886 (0.630–5.647)	0.257	–	–
Treatment parameters
Single/multiple ablated nodules	20 (57.14%)/15 (42.86%)	29 (72.50%)/11 (27.50%)	1.977 (0.754–5.186)	0.166	–	–
Total ablation volume (ml)	7.78 (4.81–16.98)	4.38 (2.84–9.36)	1.082 (1.009–1.159)	0.026	–	0.401
Ablation volume ratio (%)	46.26 (27.32–58.19)	28.69 (12.22–45.92)	1.037 (1.010–1.065)	0.007	1.037 (1.010–1.065)	0.007

RFA: radiofrequency ablation; FT3: free triiodothyronine; FT4: free thyroxine; TSH: thyrotropin; TPOAb: thyroid peroxidase antibody; TgAb: thyroglobulin antibody.

Age is expressed as mean ± standard deviation, and other continuous variables are expressed as medians (interquartile ranges, IQRs).

Table 4. Risk factors analysis of thyrotoxicosis within 1 week after RFA.

Variables	Thyrotoxicosis group	Euthyroid group	Univariate logistic regression		Multivariate logistic regression
	(n = 27)	(n = 48)	OR (95%CI)	p-Value	OR (95%CI)	p-Value
Baseline characteristics
Age (years)	38.46 ± 10.04	42.92 ± 15.74	0.976 (0.941–1.012)	0.190	–	–
Sex (female/male）	23 (85.19%)/4 (14.81%)	37 (77.08%)/11 (22.92%)	0.585 (0.166–2.056)	0.403	–	–
Hypertension	3 (11.11%)	7 (14.58%)	0.732 (0.173–3.100)	0.672	–	–
Diabetes	0 (0.00%)	3 (6.25%)	–	0.999	–	–
Thyroidectomy	3 (11.11%)	4 (8.33%)	1.375 (0.284–6.658)	0.692	–	–
Baseline FT3 (pmol/L)	4.61 (4.21–5.01)	4.43 (4.04–4.78)	2.700 (0.961–7.586)	0.060	–	–
Baseline FT4 (pmol/L)	13.63 (12.66–14.44)	13.27 (12.12–14.47)	1.061 (0.861–1.307)	0.579	–	–
Baseline TSH (μIU/ml)	1.05 (0.64–1.36)	1.56 (1.11–2.33)	0.185 (0.066–0.521)	0.001	0.178 (0.065–0.484)	0.001
TPOAb positive	4 (14.81%)	9 (18.75%)	0.754 (0.208–2.726)	0.666	–	–
TgAb positive	7 (25.93%)	10 (20.83%)	1.330 (0.440–4.025)	0.614	–	–
Treatment parameters
Single/multiple ablated nodules	15 (55.56%)/12 (44.44%)	34 (70.83%)/14 (29.17%)	1.943 (0.728–5.185)	0.185	–	–
Total ablation volume (ml)	11.08 (6.04–17.87)	4.38 (2.79–8.92)	1.128 (1.043–1.219)	0.003	–	0.314
Ablation volume ratio (%)	46.26 (29.83–58.19)	29.30 (13.17–46.63)	1.033 (1.005–1.061)	0.019	1.044 (1.011–1.077)	0.008

RFA: radiofrequency ablation; FT3: free triiodothyronine; FT4: free thyroxine; TSH: thyrotropin; TPOAb: thyroid peroxidase antibody; TgAb: thyroglobulin antibody.

Age is expressed as mean ± standard deviation, and other continuous variables are expressed as medians (interquartile ranges, IQRs).

Table 5. Analysis of different types of thyroid dysfunction in 1–12 months after RFA.

		p-Value
	Thyrotoxicosis group (n = 9)	Subclinical hypothyroidism group (n = 5)	Euthyroid group (n = 61)	Thyrotoxicosis vs. euthyroid	Subclinical hypothyroidism vs. euthyroid
Baseline characteristics
Age (years)	44.58 ± 16.88	52.78 ± 24.08	39.89 ± 12.34	0.314	0.299
Sex (female/male）	9 (100.00%)/0 (0.00%)	5 (100.00%)/0 (0.00%)	46 (75.41%)/15 (24.59%)	0.214	0.581
Hypertension	3 (33.33%)	2 (40.00%)	5 (8.20%)	0.099	0.083
Diabetes	2 (22.22%)	0 (0.00%)	1 (1.64%)	0.042	1.000
Thyroidectomy	2 (22.22%)	1 (20.00%)	4 (6.56%)	0.168	0.334
Baseline FT3 (pmol/L)	4.47 (4.20–4.88)	4.09 (3.78–4.90)	4.51 (4.15–4.86)	0.895	0.331
Baseline FT4 (pmol/L)	13.31 (12.42–15.47)	13.81 (11.88–14.44)	13.39 (12.33–14.40)	0.847	0.833
Baseline TSH (μIU/ml)	0.90 (0.69–1.22)	3.42 (2.88–3.94)	1.27 (0.96–1.83)	0.028	<0.001
TPOAb positive	0 (0.00%)	3 (60.00%)	10 (16.39%)	0.423	0.048
TgAb positive	2 (22.22%)	3 (60.00%)	12 (19.67%)	1.000	0.073
Treatment parameters
Single/multiple ablated nodules	6 (66.67%)/3 (33.33%)	4 (80.00%)/1 (20.00%)	39 (63.93%)/22 (36.07%)	1.000	0.651
Total ablation volume (ml)	7.78 (4.60–22.42)	5.86 (1.51–9.37)	6.38 (3.27–11.33)	0.313	0.368
Ablation volume ratio (%)	37.08 (23.82–54.21)	54.57 (39.39–70.59)	35.92 (18.62–48.30)	0.667	0.034
Thyroid function within 1 week
Thyrotoxicosis/euthyroid	6 (66.67%)/3 (33.33%)	–	21 (34.43%)/40 (65.57%)	0.137	–

RFA: radiofrequency ablation; FT3: free triiodothyronine; FT4: free thyroxine; TSH: thyrotropin; TPOAb: thyroid peroxidase antibody; TgAb: thyroglobulin antibody.

Age is expressed as mean ± standard deviation, and other continuous variables are expressed as medians (interquartile ranges, IQRs).