The Effect of Microwave and Radiofrequency Ablation (MWA/RFA) on Liver Volume in Patients with Primary and Secondary Liver Tumours: A Retrospective Analysis

Purpose It is known that thermal liver ablation can induce liver hypertrophy. However, exact impact in liver volume remains unclear. The aim of this study is to assess the influence of radiofrequency or microwave ablation (RFA/MWA) on liver volume in patients with primary and secondary liver lesions. Findings can be relevant in assessing the potential extra benefit of thermal liver ablation in preoperatively performed liver hypertrophy inducing procedures, such as portal vein embolization (PVE).Methods Between January 2014-May 2022, 69 invasive treatment naive patients with primary (n = 43) or secondary/metastatic (n = 26) liver lesions (in all segments, except in segments II/III) treated percutaneously by RFA/MWA were included. Total liver volume (TLV), segment II + III volume (serving as "distant liver volume"), ablation zone volume and absolute liver volume (ALV, calculated by subtracting the ablation zone volume from the TLV) were the study outcomes.Results ALV in patients with secondary liver lesions increased to a median percentage of 106.87% (IQR = 99.66-113.03%, p = 0.016), volume of segments II/III increased to a median percentage of 105.81% (IQR = 100.06-115.65%, p = 0.003). ALV and segments II/III in patients with primary liver tumours remained stable, with a median percentage of 98.72% (IQR = 92.99-108.35%, p = 0.856) and 100.43% (IQR = 92.85-109.41%, p = 0.699), respectively.Conclusion In patients with secondary liver tumours, ALV and segments II/III increased after MWA/RFA by an average of approximately 6%, while ALV in patients with primary liver lesions remained unchanged. Besides the curative intent, these findings indicate the potential added benefit of thermal liver ablation on FLR hypertrophy inducing procedures in patients with secondary liver lesions.