Despite a very favorable safety profile and a curative potential, the relatively high local tumor progression (LTP) rates after thermal ablation (TA) when compared to surgery historically, have limited the widespread use of this treatment in patients with metastatic colorectal disease to the liver. Regardless of tumor modality, treatment failure and LTP have been attributed to insufficient coverage of the tumor by the ablation zone (tumor and margins).
The ACCLAIM prospective multi-center trial aims to establish microwave ablation (MWA) as the preferred curative therapy for selected colorectal liver metastases (CLM) that can be ablated with sufficient margins. The working hypothesis is that MWA of CLM ≤ 2.5 cm with confirmation of ablation margin over 5 mm achieves definitive local tumor control (local cure) with minimal morbidity. This multicenter international study will enroll patients with one to three CLMs eligible for local cure using MWA. FDA cleared MWA devices will be acceptable for use, including technology-specific treatment planning software. MWA will be performed with the intent to create a minimum margin of ablation of 5 mm and ideally 10mm from the edge of the target tumor to the ablation periphery. Minimum margin size will be assessed after ablation using an FDA cleared image processing software to provide a qualitative 2D and 3D assessment of the ablation zone. The primary objective will assess local tumor progression-free survival at 2 years, stratified by minimum margin size: >5-10 mm and >10 mm categories. Secondary objectives include metastatic liver disease progression beyond the index tumors and beyond the liver, overall and disease-specific survival, and morbidity and quality of life after MW ablation. Subjects will be followed for a duration of 60 months.