Figure 1.

(a) An example of a best response: this is a computed tomography (CT) image from a 76-year-old woman who presented with haemoperitoneum from a bleeding left lateral segment hepatocellular carcinoma (HCC) (arrow, left CT). Multiple comorbidities and portal hypertension made surgical resection not feasible therefore she was treated with trans-arterial chemoembolization (TACE). A CT scan performed 1 month after the initial TACE revealed no evidence of a residual viable tumour (arrow right CT). Several more serial CT scans showed no evidence of a mass until she developed local recurrence/progression 2 years after the initial TACE. (b) An example of not a best response: magnetic resonance imaging (MRI) images are shown from a patient with cirrhosis and three arterial-enhancing tumours in the right liver (arrows, left MRI) treated with TACE. MRI images obtained approximately 1 month after TACE revealed a tumour response with overall loss of enhancement but some residual peripheral enhancement around two of the masses (arrows, right MRI)