Imaging Response Evaluation

A high-quality baseline staging study is one of the most important prerequisite for optimal response assessment of colorectal liver metastases (CLM). Response evaluation criteria are continuously evolving with advancing therapeutic options and technical development. Change in size and morphology are currently the key parameters used to assess response in CLM. In this chapter, we discuss the response criteria based on size and morphology that have been validated and are clinically relevant with an emphasis on the recently introduced morphological criteria. The role of functional imaging parameters including changes in SUV on PET/CT, apparent diffusion coefficient (ADC) on MRI and texture remains to be defined. We also address disappearing liver metastases and strategies to mitigate this problem. Next, we briefly discuss response evaluation after locoregional therapy. Furthermore, we review the imaging findings of chemotherapy-induced hepatotoxicity which should always be included in the radiology report.