ABSTRACT
W hile in the untreated patient we are concerned with the detection and recognition of disease, after treatment of focal liver lesions we must also be aware of the effects of different types of therapy on the residual liver itself. The treatment of benign
liver tumors, if needed at all, is generally limited to surgical resection. With malignant tumors, local ablation using radiofrequency, laser, microwave, or cryo-probes may be used either as a definitive treatment or in combination with surgery. With more widespread disease, systemic chemotherapy is usually offered. Tumors with a rich arterial supply, particularly hepatocellular carcinoma and metastases from neuro-endocrine primaries, may be treated by trans-arterial chemo-embolization (TACE). It is now commonplace for patients to be treated with combinations of systemic chemotherapy, surgery, and ablation of focal lesions. Interpreting the imaging appearances of the treated liver then requires an appreciation of the various effects which treatment itself has on the residual parenchyma as well as the characteristics of residual tumor, the likely pattern of recurrent or new disease, and the discriminating features which allow us to distinguish the side-effects or local complications of treatment from new or continuing malignancy.
