Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up

Figures & data

Table 1. Difference in volume 3 months after ablation.

Nodule	Initial volume (mL)	Volume after 3 months (mL)	Difference (mL)	Reduction (%)	Composition
1	0.48	0.35	0.13	27	complex
2	2.5	1.4	1.1	44	complex
3	22.2	9.9	12.3	55	solid
4	28.6	7.6	21.0	73	complex
5	1.7	1	0.7	41	cystic
6	6.2	2.9	3.3	53	cystic
7	4.7	1.5	3.2	68	complex
8	10.6	5.0	5.6	53	complex
9	22	10.9	11.2	51	solid
10	30	15	15	50	complex
11	3.2	1.3	1.9	59	solid
12*	0.5	0.3	0.2	40	solid
13	16	8.2	7.8	49	complex
14	37	32	5	14	solid
15	6.4	1.7	4.7	73	complex
16*	6.5	1.5	5	77	solid
17*	8	1.8	6.2	78	solid
18	20	8	12	60	complex
19	8	1.2	6.8	85	solid
20	62	18.9	43.1	70	complex
Median (range)	8 (0.48–62)	2.3 (0.3–32)	5.3 (0.13–43.1)
Mean ± SD				56 ± 17.9

Figure 1. Expansion of the ablation zone by continuous movement (a). Effective heat induction within a distinct area around the active tip. A, carotid artery; V, jugular vein; N, vagus nerve.

Figure 2. Multiple ablations (b) creating overlapping ablation zones (c). The ablation zone is more spherical as the heat rises more homogeneously between the two electrodes. A, carotid artery; V, jugular vein; N, vagus nerve.

Figure 3: Patient with dextral nodule showing unifocal thyroid autonomy before RFA (a) and 3 months after (b). Ultrasound measurements revealed a relative reduction of 77.5%. (a) length = 19 mm; height = 24 mm; width = 36 mm; volume = 8.0 cm³. (b) length = 23 mm; height = 12 mm; width = 13 mm; volume = 1.8 cm³. After ablation the patient developed a euthyroid state of function. Sufficient ablation was verified by using Doppler blood flow before ablation (c) and 3 months after the procedure (d), showing a loss of central perfusing vessels as a sign of efficient treatment.