Tumor Ablation: RFA, Microwave, and Cryoablation Explained

This page is for people who have been offered tumor ablation, mainly for liver or kidney cancer. It covers how it works, who it suits, and what recovery is like.

Ablation kills a tumor where it sits. No specimen is taken out. A doctor threads a needle-sized probe to the tumor and delivers energy that destroys the cells.

Imaging steers the probe. NCI's cryosurgery fact sheet names ultrasound or MRI for this step.

NCI's PDQ summary on primary liver cancer sorts ablation by what kills the cells. One route is a change in temperature. That covers RFA, or radiofrequency ablation, plus microwave and cryoablation. A second route is a chemical. That is PEI, or percutaneous ethanol injection, which is an alcohol shot into the tumor. A third route damages the cell membrane directly, by electroporation.

RFA passes a current through tissue to heat it until cells die. NCI's liver summary calls RFA a well-established technique for liver cancer.

Microwave ablation (MWA) heats tissue with microwave energy. PDQ lists it beside RFA as a temperature-based method.

Cryoablation freezes instead. NCI's cryosurgery fact sheet says the cold comes from liquid nitrogen or argon gas flowing through a cryoprobe. More than one probe may be used to freeze different parts of a tumor. When frozen tissue thaws, the cells die. Inside the body, that dead tissue is absorbed. On the skin, it forms a scab that falls off.

The size limit people hear about is not a rule of thumb. It comes from outcome data.

NCI's liver PDQ reports that RFA does best in tumors under 3 cm. In that group, 5-year overall survival may reach 59%. Recurrence-free survival may not differ much from surgery. Above 3 cm, PDQ says local control drops off steadily.

PEI has its own bracket. It applies to a single tumor under 3 cm in Child-Pugh class A cirrhosis, the mildest grade of liver damage. There, PDQ puts 5-year overall survival at 40% to 59%.

Head to head, PDQ says randomized trials in Child-Pugh class A cirrhosis favored RFA. RFA beat PEI on complete response (no sign of the treated tumor) and on local return. Some trials also showed better survival. RFA needs fewer sessions too. PDQ notes RFA may carry more complications than PEI. But it says both have fewer complications than cutting the tumor out.

PDQ names anatomic limits that decide the answer more than size does.

PDQ says ablation is relatively contraindicated (usually avoided) near the bile ducts, the diaphragm, and other belly organs the probe could injure.

Then there is the heat-sink effect. When a tumor sits beside a major blood vessel, flowing blood carries heat away. PDQ says thermal methods such as RFA may never reach the temperature needed, which can prevent complete tumor destruction.

Ablation is also local. It treats the site the probe reaches.

For liver cancer, PDQ positions ablation for when removal by transplant or resection is not feasible or advisable. It calls ablation useful for early hepatocellular carcinoma (the most common type of primary liver cancer) sitting deep in the liver. Cutting there would cost too much working liver tissue.

NCI's renal cell PDQ lists ablation for stage I kidney cancer. Nephrectomy means surgery to remove part or all of a kidney. The option list runs: partial nephrectomy, radical nephrectomy, simple nephrectomy, cryotherapy, thermal ablation, stereotactic radiation, and trials. PDQ calls cryoablation, thermal ablation, and stereotactic radiation curative choices. They are for people who cannot have the tumor cut out.

NCI's cryosurgery fact sheet reaches further. Its list includes:

• retinoblastoma, an eye cancer of childhood
• basal cell and squamous cell skin cancers
• skin lesions from AIDS-related Kaposi sarcoma
• early-stage prostate cancer
• liver cancer that has stayed in the liver
• bone cancer, mostly chondrosarcoma
• non-small cell lung cancer

Details differ by organ, tumor and method. Ask your team how long it will take, what sedation you will have, and whether you will go home the same day.

NCI's cryosurgery fact sheet lists possible problems by site. For the liver, these include damage to bile ducts and major blood vessels. For the prostate, they include trouble passing urine, leaking urine, erection problems and damage to the rectum.

Ask your team what follow-up scans and blood tests you will need, and when.

Ablation sits alongside other local options. The specialty behind it is described in interventional radiology in cancer care. Trade-offs against an operation are covered in surgery for cancer. The radiation choice NCI lists for stage I kidney tumors is weighed in SBRT vs. surgery.

Your temperature cutoff should come from the discharge sheet for your exact procedure. Ask for it before you leave.

• Call 911 or go to an emergency department if severe belly, chest or shoulder pain comes on suddenly, or you feel faint, or you cough up or pass blood. Bleeding and injury to nearby structures are listed complications. Do not drive yourself.
• Call your care team right away if you have fever or chills, pain that is getting worse, or a puncture site that turns red, hot, or starts oozing.
• Call your care team within a day or two if flu-like symptoms or pain are not getting better.

• NCI PDQ: liver cancer, HP version
• NCI PDQ: renal cell cancer, HP version
• NCI: cryosurgery