Recurrence patterns following irreversible electroporation for hepatic malignancies.

BACKGROUND

Irreversible electroporation (IRE) has emerged as a novel, safe ablative therapy for peri-vascular lesions. However, there remains a paucity of data on long-term outcomes.

METHODS

We identified patients who underwent open IRE (1/2011-6/2015) for primary and secondary hepatic malignancies. Local ablation-zone recurrence (LR) was determined by cross-sectional imaging. Cumulative incidence (CumI) of LR was calculated and a competing risks regression assessed factors associated with LR.

RESULTS

Forty patients had 77 lesions treated. The majority of lesions were of colorectal origin (74%). Median tumor size was 1.3 cm (range 0.5-6). Most patients (86%) had prior systemic therapy and 29% received systemic therapy following IRE. With a median follow-up of 25.7 months (range 4.5-58.8 months), 10 lesions in 9 patients recurred locally (CumI: 13.4%, 95%CI: 7.8-22.2%). Median estimated time to LR was not reached and no LR occurred after 19 months. Factors significantly associated with LR included ablation zone size (HR 1.58; 95%CI 1.12-2.23; P = 0.0093) and body mass index (HR 1.21 95%CI 1.10-1.34; P = 0.0001).

CONCLUSION

IRE LR rates were low after the treatment of well selected, small tumors. This technique is useful for lesions in anatomic locations precluding resection or thermal ablation.