Monitoring response to treatment in liver tumours.

New imaging techniques offer better ways of measuring response to treatment and remain central to the formal assessment of response in clinical trials and routine clinical practice. Increasing tumour size is consistently associated with progressive disease. However, there is evidence that the designation 'partial response', as determined by conventional imaging techniques, may not always accurately reflect the degree of treatment-induced tumour necrosis. Thus, responses classified as partial on imaging grounds have, in some cases, been shown to be complete pathological responses after surgical resection, implying that residual tumour and necrotic/fibrotic tumour remnants cannot always be accurately distinguished by imaging. In this situation, serological tumour markers such as alphafetoprotein may be useful in measuring the true degree of response. While radiological imaging is likely to remain the main method of assessing response in phase II trials of drugs for the treatment of liver cancer, it may in some instances be useful to apply additional parameters such as alphafetoprotein level.