Background: For patients with non-resectable liver metastases a response to chemotherapy is necessary in order to be able to achieve resection. Studies have shown that the response rate during neoadjuvant conversion chemotherapy is closely correlated with the frequency of resection of metastases.
Methods: Assessment of the response in clinical studies is based on the RECIST criteria. These criteria are supplemented by questions on the prognosis, tumor symptoms and toxicity for decisions on therapy. For assessment of resectability, the functional residual liver tissue and prognostic factors are important.
Results and discussion: Regular imaging controls are necessary for guiding therapy in order to avoid a continuation of chemotherapy in cases of tumor progression. Chemotherapy is normally terminated when resectability has been achieved in order to avoid additional (liver) toxicity. Morphological criteria for response to therapy (e.g. mRECIST) can be more sensitive for assessing the effects of individual therapeutic procedures but are not established for guiding systemic therapy or for comparison with other therapeutic procedures.