Computer Guided Microwave Liver Ablation

Accublate (NE Scientific, Inc) is a computer-based tumor ablation guidance software that uniquely provides real-time simulation of expected ablation volumes. In a previously reported study of Radiofrequency Ablation, the improved visualization of treated versus untreated target tumor was associated with improved outcomes. This study examines clinical application of the simulation software for microwave ablation (MWA), which will be evaluated in a 24 month two-center clinical trial.

At Dartmouth Hitchcock Medical Center (DHMC), and at one other hospital, under IRB approval, adults referred from local Liver Tumor Boards for curative local treatment of up to four Hepatocellular Carcinoma (HCC) tumors of 2-5 cm diameter will be offered participation.

After providing informed consent, and meeting inclusion and exclusion criteria, the CT-guided MWA ablation will be performed, with the physician having the benefit of the graphical display of the Accublate MWA simulation guidance software. Prior to the ablation, the software provides 3D graphical display for planning, that includes the tumor, desired margin, and interactive model of the ablation probe and superimposed expected ablation volume at particular energy settings. During placement, the software permits registration of updated image of the actual probe position to original image of the segmented tumor, and with the interactive ablation volume settings, allows assessment of adequacy of targeting. After each activation of the ablation, the calculated simulated ablation volume is provided to indicate what tissues have, and have not, been ablated. These 3D views then provide guidance for intraprocedural adjustments to ensure target coverage by overlapping ablations, if indicated.

Patients are routinely admitted for overnight observation and receive IV pain and nausea medication if needed. One month after the ablation, patients will have a follow-up outpatient contrast-enhanced abdominal CT, and from these images, the rate of complete ablation (Technical Efficacy) will be determined. Additionally, patients will be followed at 3 month intervals for 24 months after the ablation to detect any complications, tumor recurrence (Local Tumor Progression), and survival.

Inclusion criteria

• Age ≥ 18 years, with life expectancy of at least 1 year
• Diagnosis of hepatocellular carcinoma (HCC) confirmed by:

• LI-RADS 5 imaging features or
• Histopathology
• Cirrhosis with AFP > 400
• Localized disease without macrovascular invasion or extrahepatic metastasis, eligible for curative-intent percutaneous thermal ablation, defined as:

o Up to 5 lesions with at least one lesion, 2 -5 cm, and no lesion >5 cm diameter

• Tumor location deemed technically feasible for percutaneous ablation by the treating interventional radiologist
• ECOG Performance Status 0-2
• Adequate coagulation status, defined as:

• Platelets ≥ 50,000/μL
• INR ≤ 1.8 (or correctable)
• Ability to undergo contrast-enhanced CT or MRI
• Willingness and ability to provide informed consent

Exclusion criteria

• Prior local therapy to the target lesion (ablation, TACE, SBRT, or resection) or to a lesion within 1 cm of the target lesion
• More than 5 hepatic lesions, or any lesion ineligible for technically complete ablation
• uncontrolled hepatic decompensation, including:

o Persistent encephalopathy

• Uncorrectable coagulopathy or contraindication to percutaneous liver intervention
• Contraindication to contrast-enhanced imaging (e.g., severe CKD without dialysis, contrast allergy not correctable with premedication)
• Active systemic infection
• Pregnancy
• Inability to comply with follow-up imaging schedule