Ten-year survival of hepatocellular carcinoma patients undergoing radiofrequency ablation as a first-line treatment

Table 2 Potential prognostic variables and their class scores in hepatocellular carcinomas patients

Variables	Definition	Class scores1
X1	Sex	Male (1), Female (2)
X2	Age (yr)	18-60 (1), ≥ 60 (2)
X3	Pathological grade	Well-Moderate differentiated (1), Poor-differentiated (2)
X4	Etiology of cirrhosis	HBV (1), HCV (2), Alcohol (3), Others (4)
X5	Portal vein hypertension	No (1), Yes (2)
X6	Liver function enzyme	Normal (1), Elevated (2)
	(serum AST/ALT)
X7	Child-Pugh classification	A (1), B (2), C (3)
X8	Serum AFP (ng/mL)	Normal < 20 (1), Abnormal ≥ 20 (2)
X9	CEUS pre-RFA	No (1), Yes (2)
X10	Number of tumors	Single (1), ≥ 2 (2)
X11	Tumor size (cm)	≤ 3.0 (1), 3.0-5.0 (2)
X12	Risky location	No (1), Yes (2)
X13	Type of RFA electrodes	Umbrella (1), single (2)
X14	Primary technical success	Yes (0), No (1)
X15	Number of RFA sessions	1 (0), ≥ 2 (1)

¹The number in parentheses in the class scores column means the classification of variables in statistical analysis. Liver function enzyme referred to ALT and AST value, normal range was 0-40 IU/L for ALT and 0-45 IU/L for AST. CEUS pre-RFA means CEUS was performed prior to RFA to instruct treatment plan. Based on needle shape, multi-tined RITA electrode was regarded as umbrella electrode, while both internally-cooled Tyco and multi-polar Celon electrodes were regarded as single electrode. ALT: Alanine aminotransferase; AST: Aspartate aminotransferase; CEUS: Contrast enhanced ultrasound; RFA: Radiofrequency ablation.