Magnetic-resonance-guided percutaneous cryoablation of hepatic tumours

Objective: To study the feasibility of percutaneous cryoablation of hepatic tumours monitored by magnetic resonance imaging (MRI). Design: Prospective study Setting: University hospital, Norway Patients: Six patients with hepatic metastases from colorectal cancer. Interventions: Percutaneous cryoprobe positioning under general anaesthesia . Positioning and freezing monitored by near-real-time MRI using an open 0. 5 Tesla MM configuration system. Main outcome measures: Safety and feasibility of the procedure. Measurement of volumes of cryolesions. Results: One patient developed a biliary leakage that had to be drained. Fo ur patients developed pleural fluid. Two small tumours were adequately cryo ablated. In the remaining 4 patients with large (>4 cm) tumours, an adequat e cryolesion could not be formed. Cryolesion volumes larger than 105 cm(3). were not produced even using 3-4 probes. MRI visualised the growing cryole sion well, but positioning of the cryoprobes was time-consuming. Conclusion: MR guided cryoablation is clinically feasible and gives good vi sualisation of the procedure, Patients with small tumours (<3 cm) seem to b e best suited to this percutaneous approach as cryolesion volumes claimed t o be adequate for tumour destruction can be produced. Measurement of tumour volume preoperatively may help to select patients who win respond.