Technical aspects, methodological challenges, and factors predicting outcomes of percutaneous ablation for colorectal liver metastases

Abstract

Colorectal cancer is a prevalent malignancy, with colorectal liver metastases (CLM) being a common and challenging clinical issue. Traditionally, surgical resection was the only curative treatment; however, percutaneous ablation (radiofrequency, microwave, and irreversible electroporation) has emerged as a treatment option for select patients. Early trials demonstrated the efficacy of thermal ablation, leading to its inclusion in international guidelines. Currently, for small tumours, it is considered a viable alternative to resection. Recent studies demonstrate the non-inferiority of thermal ablation compared to resection in select cases and emphasize the importance of achieving an adequate ablation margin. Advancements in imaging techniques, ablative modalities, the use of image fusion, as well as ablation confirmation software, allow for a more patient-tailored approach. Additionally, tumour biology, including genetic mutations, influences both overall survival and local control, highlighting the need for personalised treatment strategies. As randomised trials continue to provide more data, the role of ablation in CLM management is evolving. This paper aims to provide a narrative review of factors predicting local control and overall survival in patients treated with ablation. Future research focusing on molecular markers, advanced imaging, and ablation verification techniques may further refine patient selection, and optimise treatment outcomes and follow-up imaging.

Keywords: colorectal liver metastasis; liver ablation; microwave ablation; radiofrequency liver ablation.