(a) A diagram of the sample collection procedure. Nineteen primary HCC patients were recruited. Before (day 0) and 1 and 7 days after RFA (day 1 and day 7, respectively), plasma and HCC tissues were collected. Most patients were treated with three RFAs, except patients 7, 9, 10 and 14, who received two treatments. RFA: radiofrequency ablation. (b and c) VEGF levels in plasma collected from patients. VEGF was measured using the Luminex cytokine assay at the indicated time points. According to the level of plasma VEGF, patients were divided into two groups: Type I (b) and type II (c). (d) Time to HCC recurrence following RFA in individual patients. (e) The mean interval for HCC recurrence was compared between type I and II patients. The values are the mean ± SEM. Note: if the interval was “>24”, “24” was used for the calculation. *p < 0.05; ***p < 0.001.