Comparison of clinical outcomes between cone beam CT-guided thermal ablation and helical tomotherapy in pulmonary metastases from hepatocellular carcinoma.

Objective: This retrospective study compares the clinical results of cone beam CT (CBCT)-guided thermal ablation with those of helical tomotherapy in hepatocellular carcinoma (HCC) patients with pulmonary metastases.

Methods: A total of 110 patients undergoing thermal ablation or helical tomotherapy for pulmonary metastases from April 2014 to December 2020 were included in the study. The endpoints were local tumor progression-free survival (LTPFS), overall survival (OS), and complications. Univariate and multivariate analyses using the Cox proportional hazard model were conducted to identify independent factors (univariate: < 0.1; multivariate: < 0.05). The Kaplan-Meier method was used to calculate the LTPFS and OS rates.

Results: The results of 106 patients were taken into the final analysis. The 1- and 3-year LTPFS rates were 50 and 19% for the thermal ablation group and 65 and 25% for the helical tomotherapy group. The median LTPFS in the thermal ablation group was 12.1 months, while it was 18.8 months in the helical tomotherapy group ( = 0.25). The 1- and 3-year OS rates were 75 and 26% for the thermal ablation group and 77 and 37% for the helical tomotherapy group. The median OS was 18.0 months in the thermal ablation group and 23.4 months in the helical tomotherapy group ( = 0.38). The multivariate analyses found that α-fetoprotein (AFP) at <400 ng/ml ( = 0.003) was significantly associated with better LTPFS. Tumor number <3 and AFP <400 ng/ml were favorable prognostic factors for OS. There were no grades 3-5 adverse events in both groups. Grade 2 was recorded in three patients (4.8%) in the thermal ablation group and two patients (4.7%) in the helical tomotherapy group.

Conclusions: For pulmonary metastases from HCC, CBCT-guided thermal ablation and helical tomotherapy provided comparable clinical effects and safety.