Radiofrequency ablation of hepatocellular carcinoma in difficult locations: Strategies and long-term outcomes

Table 1 Comparison of baseline characteristics of 382 hepatocellular carcinoma patients in the difficult group and 88 hepatocellular carcinoma patients in the control group n (%)

Characteristic	Difficult group(n = 382)	Control group(n = 88)	P value
Sex
Male	331 (86.6)	74 (84.1)	0.531
Female	51 (13.4)	14 (15.9)
Age (yr)	55.3 ± 10.1	57.4 ± 11.8	0.652
Liver cirrhosis	369 (96.6)	84 (95.5)	0.605
Child-Pugh class
Class A	235 (61.5)	62 (70.5)	0.117
Class B	147 (38.5)	26 (29.5)
Maximum diameter	3.4 ± 1.2	3.1 ± 1.1	0.071
> 3 cm	204 (53.4)	43 (48.9)
> 5 cm	40 (10.5)	5 (5.7)
Tumor number	1.4 ± 0.6	1.3 ± 0.9	0.128
Elevated AFP	172 (45.0)	38 (43.2)	0.754
Previous TACE	95 (24.9)	18 (20.5)	0.382
Previous hepatectomy	58 (15.2)	11 (12.5)	0.521

TACE: Transarterial chemoembolization; AFP: Alpha-fetoprotein.

Table 2 Outcome of radiofrequency ablation in the difficult and control groups n (%)

Group	Number of patients	Number of tumors	Tumor diameter (cm)	Early necrosis	Local progression
Control	88	170	3.1 ± 1.1	166 (97.6)	12 (7.1)1
Difficult	382	473	3.4 ± 1.2	446 (94.3)	60 (12.7)1
Near large vessels or bile ducts	87	95	3.5 ± 1.5	89 (93.7)	10 (10.5)
Near peripheral structures	232	291	3.4 ± 1.2	274 (94.2)	42 (14.4)1
Under liver capsule	63	87	3.1 ± 1.4	83 (95.4)	8 (9.2)
Total	470	643	3.3 ± 1.3	612 (95.2)	72 (11.2)

¹Local progression rate in the difficult group was significantly higher than that in the control group (12.7% vs 7.1%, P = 0.046). Local progression rate in the subgroup of tumors near peripheral structures was significantly higher than that in the control group (14.4% vs 7.1%, P = 0.018).

Table 3 Comparison of overall survival between the difficult and control groups

Group	Number of patients	Overall survival (%)1
		1-yr	3-yr	5-yr	7-yr
Control	88	92.5	60.3	43.2	32.8
Difficult	382	84.3	54.4	41.2	29.9
Near large vessels or bile ducts	87	86.3	41.4	38.0	33.8
Near peripheral structures	232	82.8	56.9	42.9	28.8
Under liver capsule	63	90.2	69.2	40.1	30.1
Total	470	85.8	56.8	41.6	30.4

¹There was no significant difference in long term survival between the difficult and control groups (P = 0.371).

Table 4 Comparison of local progression-free survival between the difficult and control groups

Group	Number of patients	Local progression-free survival (%)1
		1-yr	3-yr	5-yr	7-yr
Control	88	88.2	55.6	36.3	36.3
Difficult	382	77.9	49.0	38.0	29.1
Near large vessels or bile ducts	87	81.7	35.6	33.4	30.7
Near peripheral structures	232	77.3	48.7	38.6	27.2
Under liver capsule	63	80.5	53.1	37.8	28.1
Total	470	79.8	50.3	37.5	29.8

¹There was no significant difference in local progression-free survival between the difficult and control groups (P = 0.584).

Table 5 Multivariate analysis of prognostic factors with Cox proportional hazards in 470 hepatic cellular cancer patients after radiofrequency ablation

Variable	Wald value	P value	HR	95%CI for HR
				Lower	Upper
Child-Pugh classification	28.046	0.000	2.024	1.559	2.628
Tumor number	8.555	0.003	1.599	1.167	2.189
Liver function enzyme	4.760	0.029	1.426	1.037	1.963
Tumor size	3.951	0.047	1.262	1.003	1.589

Table 6 Comparison of major complications between the difficult and control groups

Group	Number of patients	Number of RFA	Complication (%)	Common complication name
Control	88	121	1 (0.8)1	Needle seeding (1/1)
Difficult	382	568	28 (4.9)1
Near large vessels or bile ducts	87	151	6 (4.0)	Bile duct injury (4/6)
Near peripheral structures	232	309	18 (5.8)	GI perforation (3/18) Bloody pleural (3/18) Needle seeding (3/18)
Under liver capsule	63	108	4 (3.7)	Hemoperitoneum (2/4) Needle seeding (2/4)
Total	470	689	29 (4.2)

¹The major complication rate in the difficult group was significantly higher than that in the control group (4.9% vs 0.8%, P = 0.041). RFA: Radiofrequency ablation.