Comparison between combination therapy of percutaneous ethanol injection and radiofrequency ablation and radiofrequency ablation alone for patients with hepatocellular carcinoma

Table 2 Comparison of the volume of coagulated necrosis, total energy requirement and the energy requirement for inducing coagulation of per unit volume in the groups of PEI-RFA and RFA alone.

	EtOH (mL)	L (cm)	S (cm)	H (cm)	V (cm3)	T-ENE (J)	T-ENE/V (J/cm3)
RFA alone (n = 15)	0±0	2.3±0.6	2.1±0.6	2.4±0.4	6.5±3.6	38700±12549	10010±11124
PEI-RFA (n = 60)	6.9±6.6	4.2±1.2	3.5±1.0	4.0±1.1	34.0±29.3	53828±28144	2355±1690
P	<0.0001	<0.0001	<0.0001	0.0002	<0.0001	0.73	<0.0001

Sixty patients with HCC were treated with PEI-RFA by Cool-tip RF System, while 15 patients were treated with RFA alone using the same system. After the treatment, the longest and shortest diameters and the height of the coagulated necrosis were estimated by the contrast-enhanced CT scan. Each abbreviation in the table is expressing as follows: EtOH, the amount of ethanol; L, longest diameter; S, shortest diameter; H, height; V, the volume of coagulated necrosis; T-ENE, total energy requirement; T-ENE/V, the energy requirement for inducing coagulation of per unit volume. The coagulated necrosis in PEI-RFA group was enlarged in 3 dimensions compared with the group of RFA alone, although the total energy requirement was comparable between groups.