What is the role of surgical resection combined with radiofrequency (RF) ablation in treating liver metastases (mets)?

Surgical Resection Combined with Radiofrequency Ablation for Liver Metastases

Radiofrequency ablation should be combined with surgical resection to achieve complete eradication of liver metastases when resection alone cannot eliminate all disease, particularly for patients with bilobar or multifocal disease who would otherwise be deemed unresectable. 1

Primary Role: Complementary Strategy for Complete Disease Clearance

The combination approach serves a specific and critical role when surgical resection alone cannot achieve R0 (negative margin) resection of all hepatic disease:

• RFA cannot replace surgical resection as primary treatment but functions as an essential adjunct to achieve complete tumor eradication when resection alone is insufficient 1

• Surgery remains the only treatment with curative potential on its own and should be the primary modality whenever technically feasible 1

• The combination extends surgical candidacy to patients with bilobar disease or those where functional hepatic reserve limits the extent of resection possible 2, 3

Specific Clinical Scenarios for Combined Approach

When to combine resection with RFA:

• Patients with multifocal liver metastases where some lesions are resectable but others are not due to location or inadequate future liver remnant 2, 3, 4

• Bilobar disease requiring treatment of lesions in both lobes where bilateral resection would leave insufficient hepatic volume 3, 5

• Patients with comorbidities limiting the extent of safe resection who still have some resectable disease 2

• Metastases ≤3 cm in diameter are optimal targets for RFA when combined with resection 2, 3

Technical Considerations and Limitations

Critical size threshold:

• RFA has inherent limitations for lesions >2-3 cm diameter 1
• Ablating lesions >3 cm adversely impacts survival (HR = 1.85, P = 0.04) 3
• Safety margins of ablation strongly predict complete eradication 1

Treatment burden matters:

• Combined total number of tumors treated with resection plus RFA >10 is associated with faster time to recurrence (P = 0.02) 3
• This suggests patient selection is critical—extensive disease burden may not benefit from aggressive combined approaches

Outcomes and Safety Profile

The combination approach is safe and feasible:

• Postoperative complication rates of 16-19.8% are comparable to resection alone 3, 4, 6
• Mortality rates remain low at 2.3% 3
• No increase in 90-day mortality compared to resection-only approaches 6

Survival outcomes:

• Median actuarial survival of 45.5 months for combined approach 3
• Five-year overall survival of 42% in combination group versus 62.2% in resection-only group (P = 0.001), but this reflects selection bias as combination patients had higher clinical risk scores 6
• Local failure at RFA sites is uncommon (2.3%) when performed correctly 3
• The combination provides a surgical option for patients who would otherwise be unresectable and may increase long-term survival 3

Common Pitfalls to Avoid

Do not use RFA as primary treatment when resection is feasible:

• A meta-analysis confirms surgery provides better local control and longer overall survival for colorectal liver metastases compared to RFA alone 1
• RFA should only replace resection in patients with comorbidities preventing surgery 1, 2

Avoid treating lesions near major vessels with RFA alone:

• Perivascular tumor location limits complete ablation and increases local recurrence risk 1
• Microwave ablation may provide better control of perivascular tumors than RFA 1

Do not delay surgical evaluation:

• Patients should be evaluated by hepatobiliary surgeons before starting chemotherapy to properly visualize all metastases 2
• Lesions responsive to chemotherapy may become difficult to locate after treatment 2

Integration with Systemic Therapy

Perioperative chemotherapy framework:

• For resectable colorectal liver metastases, perioperative FOLFOX chemotherapy (3 months before and 3 months after surgery) improves progression-free survival by 7-8% at 3 years 1

• Patients with poor prognostic factors (multiple metastases >5 cm, synchronous presentation, node-positive primary, high tumor markers) should receive neoadjuvant chemotherapy even if technically resectable 1

• The exception: patients with solitary metastases <2 cm can proceed directly to surgery, though this represents <10% of cases 1

Decision Algorithm

1. Assess complete resectability: Can all disease be resected with R0 margins while preserving adequate liver volume (≥30-33%)? 2

   • If yes → proceed with resection alone (add perioperative chemotherapy per risk factors)
   • If no → proceed to step 2

2. Evaluate for combined approach: Are there lesions that cannot be resected but are ≤3 cm and amenable to RFA? 2, 3

   • If yes → combine resection with RFA for complete disease clearance
   • If no → consider neoadjuvant chemotherapy to downsize or classify as unresectable

3. Verify total tumor burden: Is the combined number of lesions requiring resection + RFA ≤10? 3

   • If yes → proceed with combined approach
   • If no → reconsider candidacy; extensive disease may not benefit

4. Confirm adequate performance status and liver function to tolerate combined procedure 2, 3