High-intensity focused ultrasound: noninvasive treatment for local unresectable recurrence of osteosarcoma

Local unresectable recurrence of osteosarcoma is one of the most challenging tumors to treat. High-intensity focused ultrasound (HIFU) is a new, noninvasive technique with potential to ablate and inactivate tumors. Treatment of solid tumors with HIFU has been reported. In this study, we assessed safety and efficacy of HIFU in treating local unresectable recurrence of osteosarcoma.

We performed a retrospective analysis of 27 patients who had local unresectable recurrence of osteosarcoma from 2006 to 2010. Changes of biochemical markers and pain rating, response rate, disease control rate, local disease progression-free survival, progression-free survival (PFS) and overall survival (OS) were used to evaluate efficacy of HIFU treatment.

HIFU resulted in a significant change in alkaline phosphatase and lactic acid dehydrogenase and a remarkably relief in pain rating, without severe side effects. According to MRI examination 4-6 weeks after HIFU treatment, 2 (7.4%) patients had complete response (CR), 12 (44.4%) had partial response (PR), 9 (33.3%) had stable disease (SD) and 4 (14.8%) had progression disease (PD). The response rate was 51.8% and the local disease control rate was 85.2%. The 1-, 2-, and 3-year local disease control rates were 59.2%, 40.7% and 33.1%, respectively. The median local disease progression-free time was 14 months, the median progression-free time was 13 months and the median over-all survival time was 21 months. Patients without pulmonary metastasis had a better local disease control rate at 1-,2-,3-year and a longer local disease progression-free time, progression-free time, over-all survival time than patients with pulmonary metastasis.

HIFU is a safe and noninvasive treatment for local unresectable recurrence of osteosarcoma, with good local control and without severe complications.