Single-arm prospective study comparing ablation zone volume between time zero and 24 h after microwave ablation of liver tumors

Sadeer Alzubaidi; Alex Wallace; Sailendra Naidu; Martha-Garcia Knuttinen; Scott J Kriegshauser; Rahmi Oklu; Mustafa Al-Ogaili; Indravadan Patel

doi:10.1007/s00261-024-04185-z

Single-arm prospective study comparing ablation zone volume between time zero and 24 h after microwave ablation of liver tumors

Abdom Radiol (NY). 2024 Feb 24. doi: 10.1007/s00261-024-04185-z. Online ahead of print.

Authors

Sadeer Alzubaidi¹, Alex Wallace¹, Sailendra Naidu¹, Martha-Garcia Knuttinen¹, Scott J Kriegshauser¹, Rahmi Oklu¹, Mustafa Al-Ogaili², Indravadan Patel¹

Affiliations

¹ Division of Vascular and Interventional Radiology, Laboratory for Minimally Invasive Therapeutics, Mayo Clinic, Phoenix, AZ, 85054, USA.
² Division of Vascular and Interventional Radiology, Laboratory for Minimally Invasive Therapeutics, Mayo Clinic, Phoenix, AZ, 85054, USA. must9696afa@gmail.com.

PMID: 38400983
DOI: 10.1007/s00261-024-04185-z

Abstract

Purpose: Percutaneous thermal ablation is an effective treatment for primary and metastatic liver tumors and is a recommended local therapy for early-stage hepatocellular carcinoma (HCC). Reported evidence shows an increase in the ablation zone volume over the first 24-h post-liver ablation. This report compares ablation zone volumes immediately at the completion (T = 0) of 26 microwave ablations of liver tumors to 24-h post-procedure (T = 24) volumes.

Materials and methods: 20 patients, 13 (65%) males, underwent a total of 26 hepatic microwave ablations (MWA) under ultrasound guidance. Contrast-enhanced CT (CECT) or MRI was performed immediately and another CECT 24 h post operatively. Evaluation of the ablation zone and comparison of the two post-operative scans were done using BioTrace software. The expansion of ablation zones on post-op CECTs was matched point by point per direction. The distance between each 2 points was measured and grouped by distance. The incidence of each specific distance was then converted into a percentage, first for each case separately, then for all cases altogether. Data were tested by a matched paired one-sided t test.

Results: The median lesion diameter was 1.5 cm (range 0.5-3.3) with 16 (62%) HCC cases and 9 hepatic metastases (4 neuroendocrine carcinoma, 4 colorectal carcinomas, 1 breast carcinoma, 1 pancreatic cancer). The data show a consistent volume expansion greater than 30% (p = 7.7e-5) 24-h post-ablation, where the median expansion is 57%. Distances between T = 0 and T = 24 equal to 3-7 mm occur in over 35% of the cases.

Conclusion: The ablation zone expansion at 24-h post-op was not uniform. The final ablation zone is difficult to predict at the time of the procedure. The awareness of the ablation zone expansion is important when treating near-critical structures, managing the heat sink effect, and preserving liver parenchyma.

Keywords: Ablation; Ablation zone; Liver tumor; Malignancy; Microwave; Percutaneous.