Hepatic Tumor Thermal Ablation

Background and indications

Percutaneous thermal ablation of liver tumors (radiofrequency - RFA, microwave - MWA, or cryoablation) is a curative treatment for small liver tumors. It is recommended for early-stage hepatocellular carcinoma (HCC, BCLC 0-A, single tumor ≤ 3 cm or up to 3 tumors ≤ 3 cm each) and colorectal or other primary liver metastases (≤ 3-5 cm, limited number).

Ablation is an alternative to surgical liver resection with equivalent results for tumors ≤ 2-3 cm, particularly in cirrhotic patients or those with comorbidities limiting surgery.

Pre-procedure assessment

Assessment includes gadolinium-enhanced liver MRI (tumor characterization and planning), thoraco-abdomino-pelvic CT (staging), hepatic blood tests (bilirubin, albumin, PT, Child-Pugh score for cirrhotics), AFP measurement (HCC), and multidisciplinary tumor board discussion. Technical feasibility (percutaneous access, distance from critical structures) is evaluated.

Procedure

Under general anesthesia and CT guidance (or ultrasound with MRI fusion), one or more ablation needles are inserted percutaneously into the tumor via transcostal or subcostal approach. Microwave (MWA) is currently the most used technique, creating a 3-5 cm coagulation necrosis zone in 5-10 minutes. Radiofrequency (RFA) creates a 3-4 cm zone in 10-15 minutes. The goal is a 5-10 mm ablation margin around the tumor. Immediate post-ablation contrast-enhanced CT verifies the ablation zone. The procedure takes 1 to 2 hours.

Results and scientific evidence

For HCC ≤ 2 cm, radiofrequency ablation offers 95-100% complete ablation rate and 60-75% 5-year survival, comparable to surgical resection (Huang et al., Annals of Surgery, 2010; DOI: 10.1097/SLA.0b013e3181efc1b1). The randomized SURF trial comparing RFA and resection for HCC ≤ 3 cm confirmed ablation non-inferiority.

For colorectal liver metastases ≤ 3 cm, the CLOCC trial showed survival benefit of ablation + chemotherapy versus chemotherapy alone (Ruers et al., Journal of Clinical Oncology, 2017; DOI: 10.1200/JCO.2017.73.0628). Local recurrence rate is 5-15% for tumors ≤ 3 cm, increasing for larger tumors.

Risks and complications

Post-ablation syndrome (pain, mild fever, fatigue: 30-50%, resolving in 3-5 days), major complications (3-5%): intraperitoneal hemorrhage (1-2%), liver abscess (1-2%), biliary injury (< 1%, mainly for central tumors), pneumothorax (< 1%). Peri-procedural mortality is below 0.5%.

Recovery

1-2 night hospitalization. Return to activities in 3-5 days. Control MRI at 1, 3, 6, and 12 months, then biannual. Retreatment is possible for local recurrence.

Practical information

The procedure is performed as a short inpatient stay or outpatient depending on the case. It is performed by an interventional oncology radiologist, in coordination with the hepatologist, liver surgeon, and oncologist.