Prospective 1-year follow-up pilot study of CT-guided microwave ablation in the treatment of bone and soft-tissue malignant tumours.

ABSTRACT

PURPOSE: The aims of this work were to assess the feasibility, efficacy, short-term outcome and safety of microwave ablation (MWA) in the treatment of malignant musculoskeletal tumours. MATERIALS AND METHODS: Sixteen bone and soft-tissue malignant tumours were prospectively included and were treated by CT-guided MWA. The percentage and size of necrosis of the lesions were measured by contrast-enhanced MRI before the procedure and after 1, 3, 6 and 12 months. mRECIST criteria were used to assess tumour response. Procedural success was defined as ≥80 % necrosis. Patient pain (as assessed using a numeric visual scale (NVS)) and side effects were noted. RESULTS: Six osteolytic metastases, five osteoblastic metastases and five soft tissue sarcomas were treated. At 1 month, 40 % were treated completely, the percentage of necrosis was 85 ± 30.4 %, and the success rate was 80 %. At 3, 6 and 12 months the success rate was 80 %, 76.9 % and 63.6 %, respectively. At 12 months, four lesions (36.3 %) still had no recurrence. Mean NVS during the procedure was 3.5 ± 2.8. One patient had transitory sciatica without neurological deficit that was treated medically. CONCLUSION: CT-guided MWA of bone and soft-tissue malignant tumours is efficient, well tolerated and has good short-term anti-cancer effects. KEY POINTS • CT-guided MWA is efficient in treating musculoskeletal malignant tumours. • This prospective pilot study showed MWA induces high percentages of tumour necrosis. • MWA has good short-term anti-cancer effects. • MWA has healing potential when lesions can be completely necrosed. • CT-guided MWA under equimolar mixture of oxygen-nitrous oxide inhalation is well tolerated.