Enhancement of antitumor vaccine in ablated hepatocellular carcinoma by high-intensity focused ultrasound

Figure 2 High-intensity focused ultrasound-generated vaccine inhibits tumor growth after a subsequent tumor challenge in a mouse H22 tumor model. Naïve mice were vaccinated with high-intensity focused ultrasound (HIFU)-generated and tumor-generated vaccines, and saline alone once a week for 2 wk. The mice bearing H22 tumors were also treated with HIFU ablation. 7 d after the 2nd vaccination, the vaccinated animals were challenged with 2 × 10⁶ viable H22 cells, and the HIFU-treated mice received a second tumor challenge with the same number of H22 cells 15 d after HIFU therapy. Tumor diameters were measured for 3 wk, and the results were reported as the tumor volume. All mice were followed up for 48 d, and a cumulative survival rate was calculated in each group. A: The tumor volume, measured with a Vernier caliper, in the vaccinated and HIFU-treated mice after a subsequent tumor challenge. ^aP < 0.05 vs the control; ^cP < 0.05 vs the tumor-generated vaccine; B: Cumulative survival curves, calculated with the Kaplan-Meier method, in the vaccinated and HIFU-treated mice. Compared to the other groups, HIFU therapy shows a significant increase in survival (P < 0.001, the log-rank test).