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

Table 4 Comparative study of coagulated necrosis in the groups classified according to the total energy requirement in PEI-RFA.

	EtOH (mL)	L (cm)	S (cm)	H (cm)	V (cm3)	T-ENE (J)	T-ENE/V(J/cm3)
T-ENE <53828J	5.8±5.8	3.6±0.8	3.2±0.8	3.6±1.0	24.6±17.3	32003±12743	2038±1638
(n = 32)					-1
T-ENE >53828 J	8.1±7.3	4.8±1.2	3.8±1.2	4.4±1.2	44.0±36.4	77884±19567	2727±1687
(n = 28)					-1.8
P	0.23	0.0002	0.04	0.0028	0.014	<0.0001	0.052

All cases treated with PEI-RFA were divided into two groups. One was high energy group and the other low energy group according to the mean amount of total energy requirement (53828 Joule). 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 amount of ethanol injected was statistically comparable in both groups. The volume of coagulated necrosis in the high energy group was 1.8 times larger than that in the low energy group. The degree of the enhancing effect was smaller compared with that in cases classified by the mean amount of injected ethanol as shown in Table 3. Furthermore, the energy requirement for coagulation of per unit volume was comparable between groups.