Effectiveness of impedance monitoring during radiofrequency ablation for predicting popping

Table 1 Patient characteristics (140 patients, 148 nodules)

Characteristics	Value
Male/female (n/n)	94/46
Age (yr)	73.0 ± 11.1
ICGR 15 (%)	22.6 ± 14.4
Maximum tumor diameters (mm)	21.9 ± 7.1
Hepatocellular carcinomas	132
Metastatic liver cancers	14
Intrahepatic cholangiocarcinomas	2
Tumor locations
Segment 1	3
Segment 2	11
Segment 3	23
Segment 4	13
Segment 5	20
Segment 6	22
Segment 7	23
Segment 8	33
RFA needle lengths (2 cm/3 cm)	79/69
Ablation time (s)	862 ± 613

Data are presented by mean ± SD or n. RFA: Radiofrequency ablation; ICGR 15: Indocyanine green retention rate at 15 min.

Table 2 Tumor characteristics for each impedance type (148 nodules)

Impedance subtype	Maximum tumor diameter (mm)1	ICGR 15 (%)1	Tumor location(segments 1,2,3,4,5,6,7,8)2
A	20.3± 6.0	17.8 ± 13.9	(0,1,0,0,0,0,0,1)
B	20.4 ± 5.3	29.8 ± 10.7a	(1,1,1,1,1,2,1,1)
C	21.2 ± 8.1	19.9 ± 11.1	(0,3,3,3,5,3,3,6)
D	22.7 ± 6.7	24.2 ± 17.9	(0,2,8,4,8,6,4,11)
E	22.7 ± 6.3	21.4 ± 10.2	(1,2,1,2,1,3,8,5)
F	22.3 ± 7.8	24.1 ± 15.9	(1,1,4,1,3,5,3,3)
G	20.9 ± 8.1	20.2 ± 14.0	(0,1,5,2,2,4,4,6)

^aP = 0.028 vs type C (P = 0.028).

¹Data are means ± SD;

²Data are numbers of nodules. ICGR 15: Indocyanine green retention rate at 15 min.