This protocol is for a prospective multi-centre clinical trial of the use of RFA aspiration in the treatment of patients with primary/secondary malignancies of the liver, which are not suitable for formal liver resection. The basis for unresectability being the presence of extra-hepatic disease, limited liver synthetic function, co-morbidity (ASA>3), bilobar disease and anatomical location. Early and late complications relating to the usage of the RFA aspirator will be analysed. Additionally, local recurrence and long term survival will be assessed. If the use of the RFA aspirator produces improved survival with minimal morbidity and mortality. Then these initial results will justify further in depth studies to establish its clinical role.