Table 3.

Comparative study of coagulated necrosis in the groups classified according to the amount of ethanol injected in PEI-RFA.

	EtOH (mL)	L (cm)	S (cm)	H (cm)	V (cm3)	T-ENE (J)	T-ENE/V (J/cm3)
EtOH <6.9 mL	3.1±1.6	3.8±0.9	3.0±0.6	3.6±0.9	22.3±14.3	48 901±23219	2796±1752
(n = 41)					-1
EtOH >6.9 mL	14.9±6.1	5.1±1.3	4.3±1.2	4.8±1.1	57.6±38.2	63 931±34744	1460±1016
(n = 19)					-2.6
P	<0.0001	0.0002	<0.0001	0.0003	<0.0001	0.11	0.0014

The mean volume of ethanol injected in PEI-RFA was 6.9 mL. Therefore, 60 patients treated with PEI-RFA were divided into two groups according to the amount of ethanol injected. One group (high EtOH group) consisted of 19 cases administered with 6.9 mL and more ethanol, and the other (low EtOH group) of 41 cases less than 6.9 mLethanol. 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 volume of coagulated necrosis in the high EtOH group was 2.6 times larger than that in the low EtOH group, although the total energy requirement was comparable between groups.