Radiological monitoring of the treatment of solid tumors in practice.

PURPOSE Thanks to advances in cancer therapy, the diagnosis of "incurable cancer" is increasingly able to be changed to a chronic disease that is manageable over long periods, resulting in a change in the clinical management of cancer patients with solid tumors. New parameters are needed to measure the success of targeted therapy in clinical trials. MATERIALS AND METHODS Review article on the basis of selective literature research. RESULTS In order to assess how well solid tumors respond to treatment, size-based criteria called RECIST (Response Evaluation Criteria in Solid tumors) have been defined. These criteria have been validated in large oncology trials and are currently used most frequently. New molecular therapies often do not - or at least do not immediately - reduce the size of a tumor. Therefore, RECIST evaluation should be critically assessed especially in the case of modern therapies. Any additional available tumor biology information should be considered. In radiology new methods and developments of RECIST have been introduced to better assess the success of targeted therapy. CONCLUSION Assessment according to RECIST has been proven for the follow-up of classic tumor therapy. For the monitoring of targeted therapies, new parameters are often required. Therefore, some specific tumor- and therapy-adapted criteria have already been defined to better evaluate treatment success in clinical trials.