Percutaneous microwave thermosphere ablation of pancreatic tumours.

Background: In oncologic field, thermo-ablative procedures have spread more and more. Percutaneous microwave ablation (MWA) showed same benefits and some advantages over radiofrequency ablation (RFA). To date, a disadvantage of both was the not totally predictable size and shape of ablation volume. The aim of this study was to assess feasibility and safety of MWA in nonresectable pancreatic head cancer using a new technology of MW with high power (100 W) and frequency of 2,450 MH.

Methods: Five patients with pancreatic head cancer treated with percutaneous MWA under ultrasound guidance were retrospectively reviewed. Mean lesion diameter was 27.8 mm (range, 25-32 mm). Follow-up was performed by CT after 1, 3, 6 and, when possible, 12 months. The shape of the ablation volume was evaluated with multiplanar reformatting (MPR) using roundness index (RI): a value near 1 represents a more spherical ablation zone shape, and a value distant from 1 implies an oval configuration. Ablation and procedure times were registered, together with hospital stay. The feasibility, safety and quality of life (QoL) were reported.

Results: The procedure was feasible in all patients (100%). A spherical shape of ablation zone was achieved in all cases (mean RI =0.97). Mean ablation and procedure time were respectively of 2.48 and 28 minutes. Mean hospital stay was 4 days. No major complications were observed. Minor complications resolved during the hospital stay. An improvement in QoL was observed in all patients despite a tendency to return to preoperative levels in the months following the procedure.

Conclusions: Percutaneous MWA is a feasible and safe approach for the palliative treatment of advanced stage tumors of the head of the pancreas, despite its complex anatomic relations. The spherical shape of the ablation volume could be related with an improving of the effectiveness and safety.