Superficial malignant tumors: Non-invasive treatment with ultrasonographically guided high-intensity focused ultrasound

The purpose of this study was to evaluate the effectiveness of ultrasonographically guided high-intensity focused ultrasound (HIFU) ablation for superficial malignant tumors. HIFU ablation was applied to 38 cases. The diameter of tumors ranged from 1.5-18 cm, including < or =3 cm in seven cases, >3 to < or =5 cm in four cases, >5 to <10 cm in 15 cases, and > or =10 cm in 12 cases. Using imaging techniques, the volume and activity of tumors were observed before and after HIFU ablation, and the effectiveness of HIFU ablation in superficial malignant tumors was evaluated. For tumors < or =5 cm in diameter, HIFU ablation was completely effective in 100% (11/11) of cases; for tumors >5 cm in diameter, HIFU ablation was completely effective in 25.9% (7/27) of cases, partially effective in 14.8% (4/27) of cases, moderately effective in 33.3% (9/27) of cases; the disease remained stable in 14.8% (4/27) of cases and progressed in 11.1% (3/27) of cases. No significant difference was observed in the tumor volumes before (202.6 +/- 230.4 cm(3)) and 6-8 w after HIFU ablation (188.1 +/- 215.8 cm(3)). However, the difference in the active volume before (202.6 +/- 230.4 cm(3)) and after (127.6 +/- 189.7 cm(3)) HIFU ablation was statistically significant. Among 38 the cases, 32 reported painful symptoms, with a pain score of 4.39 +/- 2.36, before the ablation; the values dropped to 0.19 +/- 0.54 after HIFU, and the difference was statistically different. Thus, HIFU is a safe, effective and promising approach for the treatment of superficial malignant tumors.