Introduction
Radiofrequency Ablation (RFA) is a minimally invasive, image-guided thermal ablation technique used by interventional radiologists to destroy tumors by applying localized heat.
It has become a mainstay in liver, kidney, lung, and bone tumor treatment, especially for patients who are poor surgical candidates.
Principle of RFA
- RFA delivers alternating high-frequency electrical current through an electrode into tumor tissue.
- Ionic agitation generates frictional heat (>60°C), causing coagulative necrosis.
- The ablated tissue is gradually resorbed or replaced by scar tissue.
Indications
Liver:
- Small hepatocellular carcinoma (HCC) ≤3 cm
- Liver metastases (e.g., colorectal origin)
Kidney:
- Small renal masses in patients unfit for surgery
Lung:
- Peripheral non-small cell lung cancer (NSCLC)
- Pulmonary metastases
Bone:
- Pain palliation in osteoid osteoma and metastatic bone lesions
Contraindications
- Uncorrectable coagulopathy
- Tumors adjacent to critical structures where thermal injury is unacceptable (e.g., major bile ducts, spinal cord)
- Diffuse metastatic disease without local control benefit
Procedure Technique
- Pre-procedure Planning – Imaging (CT/MRI/US) to define tumor size, number, and location.
- Patient Preparation – Conscious sedation or general anesthesia.
- Imaging Guidance – US, CT, or MRI used to place the RFA electrode precisely into the tumor.
- Ablation Phase – High-frequency alternating current applied for 10–30 minutes per lesion.
- Track Ablation – Prevents seeding or bleeding during electrode withdrawal.
- Post-procedure Scan – Confirms complete coverage of the target zone.
Imaging Guidance Options
- Ultrasound – Real-time, portable, commonly used for liver tumors.
- CT – Precise localization, preferred for lung and deep-seated lesions.
- MRI – Excellent soft tissue contrast; limited availability.
Post-Procedural Imaging Findings
- Non-enhancing ablation zone on contrast CT/MRI
- Gradual shrinkage of treated area over months
- No evidence of nodular peripheral enhancement (recurrence indicator)
Advantages of RFA
- Minimally invasive, outpatient or short-stay procedure
- Repeatable if recurrence occurs
- Spares surrounding healthy tissue
- Preserves organ function
Complications
- Post-ablation syndrome (fever, malaise, mild pain)
- Hemorrhage
- Thermal injury to adjacent structures
- Tumor seeding (rare)
Outcomes
- Best results in tumors ≤3 cm
- Comparable local control to surgical resection in select small HCCs
- Useful palliative tool in metastatic disease
Future Developments
- Combination therapy with TACE for larger liver tumors
- Multi-probe techniques for improved coverage
- AI-assisted targeting to optimize electrode placement
Key Takeaways
- RFA is a safe, effective, organ-preserving treatment for small tumors.
- Careful patient selection and precise image-guided technique are essential.
- Plays a central role in interventional oncology alongside MWA and cryoablation.
