Prospective pilot study of CT-guided microwave ablation in the treatment of osteoid osteomas

Abstract

The aims of this work were to assess the feasibility and efficacy of CT-guided microwave ablation (MWA) in the treatment of osteoid osteomas (OOs). Thirteen consecutive patients (range 11-31years old) presenting with OO were prospectively included and treated by CT-guided MWA. Power and duration of MWA were both recorded. The patient's pain was assessed using a numeric pain rating scale (NRS), and side effects were recorded during procedures, after 1day, 7days and 1month. The nidus vascularization and the volume of necrosis induced by MWA were assessed using contrast-enhanced MRI. Success was defined as the complete relief of the patient's pain 1month after the first procedure, associated with necrosis of the nidus on follow-up MRI. The success rate was up to 92.3% (12/13). At 1day, 7days and 1month, the median NRSs were respectively 5 [interquartile range (IQR) 2-5], 0 (IQR 0-1) and 0 (IQR 0-0). Side effects observed were one partial and self-resolving lesion of a sensory branch of the radial nerve and two skin burns. The median power of the MWA used was 60W (IQR 50-60) with a 1.5-min duration (IQR 1-2), leading to MWA-induced necrosis measuring on average 23 × 15 × 16mm. CT-guided MWA of OO has a success rate that appears to be almost similar to that of laser or radiofrequency ablation, but care must be taken to prevent nerve or skin lesions.