Ultrasound-guided high intensity focused ultrasound treatment for extra-abdominal desmoid tumours: preliminary results.

PURPOSE The aim of this study was to evaluate the feasibility, safety and therapeutic effects of ultrasound (US)-guided high intensity focused US (HIFU) ablation in the treatment of extra-abdominal desmoid tumours. MATERIALS AND METHODS From May 2006 to May 2010, ten consecutive patients with pathologically proven extra-abdominal desmoid tumours were treated by US-guided HIFU ablation. Eight patients with multiple recurrent tumours were treated with a palliative aim, two patients with new solitary tumours were treated with a curative aim. The mean size of the largest tumour was 9.2 cm (range 5.9-12.8 cm). An acoustic power of 300-500 W was used according to the echogenic changes after energy exposure, intermittent HIFU exposure of 2-3 s was applied until the planned target area became hyperechoic on US. Outcome of HIFU ablation was observed by serial contrast-enhanced imaging examinations during follow up. RESULTS HIFU ablation was successfully performed without major complications. Large volume coagulation necrosis was obtained in all patients. During a mean follow up of 30 months (range 8-55 months), the treated tumours (n = 25) shrank significantly (>50% in volume). Complete tumour necrosis was observed in the two patients with solitary new tumours. Two patients received repeat HIFU ablation for enlarged residual tumours. No tumour spread along the treated area was observed in any patient. CONCLUSION US-guided HIFU ablation could be used as an effective minimally invasive therapy for local control of extra-abdominal desmoid tumours.