Lesion mapping and radiological monitoring of metastases?

Accurate imaging is central to the management of colorectal liver metastases (CRLM) and is now fully integrated into therapeutic decision-making. Lesion mapping has evolved from a descriptive approach to a surgical-oriented process, aiming to define the spatial distribution, vascular relationships, and resectability of disease. Liver MRI with hepatobiliary contrast agents combined with diffusion-weighted imaging provides optimal sensitivity for lesion detection, particularly for subcentimeter disease, while offering insight into tumor viability. Artificial intelligence is increasingly incorporated into this initial assessment, improving lesion detection, automated segmentation, and preoperative mapping.
Treatment response assessment relies primarily on RECIST criteria, which remain robust, standardized, and clinically effective in routine practice. However, size-based evaluation does not fully capture tumor biology. Morphological changes, including changes in lesion attenuation, homogeneity, and enhancement patterns, provide complementary information that may better reflect therapeutic efficacy. Particular attention should be given to disappearing metastases, as radiological complete response does not equate to pathological eradication.
Post-treatment imaging, following surgery or local ablative therapies, requires careful evaluation of recurrence patterns and local control. Emerging approaches, including artificial intelligence, hold promise for improving response assessment and enabling more personalized treatment strategies.