Microwave ablation of malignant liver lesions: Does the presence of cirrhosis affect the diameter of the ablation zones? A retrospective comparative study from a single institution.
Thermal ablation techniques, such as radiofrequency ablation (RFA) and microwave ablation (MWA), are used to treat hepatic malignancies. The 'oven effect,' where background cirrhotic tissue insulates and enhances heating, is well-documented in RFA but not in MWA. This study aims to explore whether the oven effect occurs in MWA.
A retrospective comparative study included all patients undergoing MWA for hepatic malignancies between 2014 and 2017. Patients were divided into two groups based on liver lesion characteristics: H group (hepatocellular carcinoma, likely cirrhotic liver) and M group (metastases, likely non-cirrhotic liver). Ablation volumes were calculated using CT scans performed 6 weeks post-ablation. Multivariate linear regression analysis was performed to assess the significance of differences in ablation volume.
94 patients (57 in H group, 37 in M group) were included. Groups were demographically matched, and ablation parameters (intensity and duration) were comparable. The mean ablation volume in the M group was 2.3cm³ smaller than in the H group, but this difference was not statistically significant (95% confidence interval -7.8, 3.3; p = 0.42).
This study found no evidence of the oven effect phenomenon in MWA. This may result from MWA's ability to achieve higher temperatures and larger ablation zones, reducing the impact of local tissue characteristics.
This study provides preliminary evidence that MWA produces consistent ablation volumes regardless of liver background, suggesting it is a reliable method for both cirrhotic and non-cirrhotic livers, advancing patient-specific treatment planning. However prospective validation is required before integration into clinical guidelines.
A retrospective comparative study included all patients undergoing MWA for hepatic malignancies between 2014 and 2017. Patients were divided into two groups based on liver lesion characteristics: H group (hepatocellular carcinoma, likely cirrhotic liver) and M group (metastases, likely non-cirrhotic liver). Ablation volumes were calculated using CT scans performed 6 weeks post-ablation. Multivariate linear regression analysis was performed to assess the significance of differences in ablation volume.
94 patients (57 in H group, 37 in M group) were included. Groups were demographically matched, and ablation parameters (intensity and duration) were comparable. The mean ablation volume in the M group was 2.3cm³ smaller than in the H group, but this difference was not statistically significant (95% confidence interval -7.8, 3.3; p = 0.42).
This study found no evidence of the oven effect phenomenon in MWA. This may result from MWA's ability to achieve higher temperatures and larger ablation zones, reducing the impact of local tissue characteristics.
This study provides preliminary evidence that MWA produces consistent ablation volumes regardless of liver background, suggesting it is a reliable method for both cirrhotic and non-cirrhotic livers, advancing patient-specific treatment planning. However prospective validation is required before integration into clinical guidelines.
Authors
Shaygi Shaygi, Burger Burger, Reed Reed, Ashraf Ashraf, Weston-Petrides Weston-Petrides, Puttick Puttick, Hamed Hamed, Luigi Luigi, Peddu Peddu
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