Radiofrequency ablation of small follicular neoplasms: initial clinical outcomes

Figures & data

Figure 1. Flow chart of patient in this study.

Table 1. Demographic characteristics of the enrolled patients.

Characteristic	Radiofrequency Ablation (n = 10)
Gender (male:female)	0:10
Age (years)	41.8 ± 11.2 (30–57)
Nodule diameter (cm)	1.4 ± 0.3 (1.0–1.9)
Nodule volume (ml)	0.6 ± 0.4 (0.2–1.6)
Symptom score	0
Cosmetic score	1.4 ± 0.5 (1–2)
Vascularity	2.6 ± 0.7 (2–4)

Values represent the mean ± SD and the numbers in parenthesis represent the range.

Table 2. Treatment characteristics of the 10 follicular neoplasms.

	Initial RFA	Additional RFA	Total
RF power (W)	18.5 ± 2.4 (15–20)	20.0 ± 0 (20)	18.8 ± 2.3 (15–20)
Ablation time (s)	232.5 ± 123.5 (110.0–420.0)	175.0 ± 35.4 (150.0–200.0)	222.9 ± 114.5 (110.0–420.0)
Total energy (J)	4325.0 ± 2323.9 (1650.0–8400.0)	3500.0 ± 707.1 (3400.0–4000.0)	4187.5 ± 2137.1 (1650.0–8400.0)
Energy/ml (J)	8397.5 ± 5203.8 (3975.8–19331.8)	13482.2 ± 5922.9 (9294.1–17670.3)	9245.0 ± 5409.4 (3975.8–19331.8)
Number of RF sessions	10	2	12
Solid component^a
Solid	10	–

Values represent the mean ± SD and numbers in parenthesis represent the range.

^a The solid component is defined as solid (if the solid component is >50%) and predominantly cystic (if the solid component is between 10% and 50%).

Figure 2. A 31-year-old woman with a right thyroid nodule proven to be a follicular neoplasm on core needle biopsy. (A) A well-defined hypoechoic solid thyroid nodule on the transverse US image. (B) An echogenic totally ablated thyroid nodule with a RF electrode (arrows) on the transverse US image. (C) One month after RFA, the nodule had decreased and there was no undertreated area. (D) Two years after RFA, the nodule had disappeared.

Table 3. Outcomes for the 10 follicular neoplasms after RF ablation.

Variables	Before	1-month	1-year	2-year	3-year	4-year	5-year	p Value^a
Largest diameter	1.37 ± 0.33	1.00 ± 0.34	0.50 ± 0.23	0.20 ± 0.23	0.08 ± 0.17	0.07 ± 0.15	0.07 ± 0.15	<0.0001
Volume	0.64 ± 0.43	0.26 ± 0.19	0.05 ± 0.10	0.01 ± 0.01	0.00 ± 0.01	0.00 ± 0.00	0.00 ± 0.00	0.0012
Volume reduction rate (%)	–	55.20 ± 22.04	94.09 ± 6.08	98.60 ± 2.79	99.21 ± 1.78	99.54 ± 0.99	99.54 ± 0.99
Symptom score	0	0	0	0	0	0	0
Cosmetic score	1.40 ± 0.52	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.0455
Vascularity	2.60 ± 0.70	0.6 ± 1.3	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.00 ± 0.00	0.0042
Therapeutic success (%)^b		9/10 (90)	10/10 (100)	10/10 (100)	10/10 (100)	10/10 (100)	10/10 (100)

Values represent the means ± SD, except for therapeutic success.

^a Comparison of values before and 5-year follow-up.

^b Therapeutic success (volume reduction >50%).