Navigating Disappearing Liver Metastases in Colorectal Cancer: A Review of Surgical and Non-Surgical Approaches.

Colorectal liver metastases pose a significant clinical challenge for the multidisciplinary team (MDT), with the phenomenon of disappearing liver metastases (DLMs) following chemotherapy adding further complexity. DLMs, defined as the radiological disappearance of liver metastases after systemic therapy, require careful evaluation as the pathological complete response is not always guaranteed. To comprehensively address and analyse the key aspects of this complex issue, we performed a literature search using PubMed and Embase, focussing on studies reporting outcomes of different treatment approaches, imaging techniques, and prognostic factors. The current evidence emphasises the pivotal role of advanced imaging modalities-such as gadolinium ethoxybenzyl dimeglumine-enhanced magnetic resonance imaging (MRI) and contrast-enhanced intraoperative ultrasound-in accurately assessing high-risk patients with DLMs (eg, lesions <2 cm, synchronous metastases or those treated with oxaliplatin-based chemotherapy). Using these techniques both preoperatively and intraoperatively is crucial for precise localisation of DLMs. The literature also highlights the importance of an MDT approach to optimise patient management, ensuring treatment decisions are tailored to individual patient and tumour characteristics. A 'watch-and-wait' strategy may be appropriate for selected patients with favourable prognostic factors, whereas locoregional treatments are preferable for fit patients with adequate residual liver volume or DLMs adjacent to visible residual disease. To support clinical decision-making, our group has developed a simplified algorithm to guide clinicians.