Microwave ablation (MWA) and radiofrequency ablation (RFA) for liver cancer both destroy tumors with heat delivered through a thin needle placed through the skin. In a five-hospital Japanese randomized trial of 236 patients with liver cancers up to 4 cm, the rate of the tumor growing back at the treated site within two years was 16.4% after microwave ablation and 30.4% after radiofrequency ablation. Overall survival was similar with both procedures.
Based on the Japanese multicenter trial in JHEP Reports, a French–Swiss trial in The Lancet Gastroenterology & Hepatology, NICE guidance and UK hospital patient leaflets, this article explains how the two procedures differ, who they are for, what the head-to-head trials found, and what the procedure and recovery look like.
Treatment status · Both microwave ablation and radiofrequency ablation are established treatments already used in Japan, Europe and the United States. The figures here come from randomized trials that compared the two directly (a Japanese multicenter trial and a French–Swiss phase 2 trial). This is general information, not a treatment recommendation.
What is the same and what is different?
The basic approach is the same. Guided by ultrasound or CT, the doctor passes a thin needle (electrode) through the skin into the center of the tumor and heats the tip to destroy the tumor together with a margin of surrounding liver. There is no open incision, so the wound is small and the strain on the body is lower than with liver surgery.
The difference is how the heat is made. Radiofrequency ablation passes an electrical current between the needle and pads placed on the body, and the tissue heats up as it resists the current. Microwave ablation works like a microwave oven, agitating water molecules around the needle directly. Tokyo Medical University notes that newer-generation microwave systems can create a wide, spherical ablation zone in a short time.
| Item | Microwave ablation (MWA) | Radiofrequency ablation (RFA) |
|---|---|---|
| How heat is made | Microwaves agitate water molecules | Resistive heating as current passes through tissue |
| Pads on the body | Not needed | Needed (rarely, small burns at the pad site) |
| Ablation zone | Designed to create a wide, round zone quickly | Relatively smaller zone per single needle |
| Tumors near blood vessels | Known to be less affected by heat loss to blood flow | Blood flow in large vessels can cool the zone |
| Long-term data | Data on newer systems growing quickly | Longest track record with extensive long-term data |
Summarized from the Norfolk and Norwich University Hospitals leaflet, the Tokyo Medical University release and NICE guidance. Actual zone size and time depend on the device and tumor location.
For the usual steps and hospital stay of radiofrequency ablation, see RFA for liver cancer: procedure and recovery, and for needle-based local treatment in general, see our RFA guide.
Who is it for?
Both procedures are treatment options alongside surgery for small, few hepatocellular carcinomas. The two comparison trials enrolled the following patients.
- Japanese multicenter trial: hepatocellular carcinoma not suited to surgery, up to 4 tumors, each 4 cm or smaller
- French–Swiss trial: chronic liver disease, not eligible for surgery, up to 3 tumors, each 4 cm or smaller
In practice, doctors weigh tumor size and number, liver function (Child-Pugh class), and how close the tumor is to large vessels, bile ducts, the gallbladder or the bowel. NICE advises that patients be selected by a multidisciplinary team that includes a hepatobiliary surgeon. For the tests used to check liver function and stage, see tests before liver cancer procedures.
Trial results: 236 patients in Japan and 152 in Europe
Below are the figures, exactly as reported, from two of the larger and more recent randomized trials comparing the two procedures. "Local tumor progression" means the cancer growing back at the edge of the treated area.
| Item | Japanese multicenter trial | French–Swiss phase 2 trial |
|---|---|---|
| Journal | JHEP Reports 2025 (online December 2024) | Lancet Gastroenterology & Hepatology 2018 |
| Centers and period | 5 hospitals in Japan, July 2018 to December 2021 | 4 university hospitals in France and Switzerland, November 2011 to February 2015 |
| Patients treated | MWA 119 (130 tumors), RFA 117 (136 tumors) | 152 randomized (76 each) |
| 2-year local progression | MWA 16.4% vs RFA 30.4% (risk ratio 0.54, p=0.007) | MWA 6% vs RFA 12% (no significant difference, p=0.27) |
| Overall survival | No significant difference | Primary endpoint was local progression; 5-year follow-up planned |
| Serious complications | Two in each group; no treatment-related deaths | MWA two grade 4 (arterial bleeding treated by embolization), RFA three grade 3; no treatment-related deaths |
The two trials used different devices and patient groups, so the numbers cannot be compared directly.
The Japanese trial compared a newer-generation microwave system (Emprint) with single-needle radiofrequency ablation, and the two-year risk of local progression with microwave ablation was about half. The Tokyo Medical University team concluded that microwave ablation is more effective in reducing local progression for tumors up to 4 cm. Recurrence elsewhere in the liver, recurrence outside the liver and overall survival were similar.
In the French–Swiss trial, two-year local progression was low with both methods, at 6% and 12%. In short, both procedures are reliable treatments for small liver cancers, and in the Japanese trial with a newer device, microwave ablation further reduced regrowth at the treated site. For results of thermal ablation in other settings, see thyroid nodules: RFA vs microwave and ablation for colorectal liver metastases.
The procedure and recovery time
The typical course of microwave ablation below is based on leaflets from King's College Hospital (October 2025 edition) and Norfolk and Norwich University Hospitals. Radiofrequency ablation follows almost the same steps.
| Step | What happens | Time |
|---|---|---|
| Preparation | Clotting blood tests; blood thinners stopped as directed by your doctor; fasting from midnight (clear fluids until two hours before) | A few days to a week before |
| Anesthesia | Usually general anesthesia; some hospitals use sedation | Day of procedure |
| Ablation | Needle placed under CT or ultrasound; each ablation takes 5 to 30 minutes | About 1 hour, up to 2 hours |
| Hospital stay | Observed overnight; home the next day if all is well | Usually one night |
| Return to daily life | Avoid heavy lifting and strenuous exercise; most take about a week off work | 1 to 2 weeks |
| Checking the result | CT to confirm the tumor was fully treated, then regular scans | 4 to 6 weeks after |
Anesthesia and length of stay can vary by hospital and country.
Keep the puncture site dry for 48 hours, then wash gently with soap and water. Leaflets advise avoiding baths until the wound has healed.
Side effects and how they are managed
According to the King's College Hospital leaflet, the most common reaction is post-ablation syndrome: about 1 in 4 patients have mild flu-like symptoms or fever two to three days after the procedure. It usually settles within two to three days with rest and plenty of fluids. Contact your care team promptly if your temperature rises suddenly or you feel very unwell.
Damage to nearby organs (gallbladder, stomach, lung, bowel), serious bleeding and infection each occur in fewer than 1 in 100 patients. If the needle passes near the diaphragm, shoulder discomfort may occur and is managed with oral pain relief. With radiofrequency ablation, very rare burns can occur at the pad sites, so the skin is checked before and after.
How it is used in Japan and abroad
| Region | Status | Basis |
|---|---|---|
| Japan | The 2021 Japanese liver cancer guidelines recommend RFA as needle-based local therapy. Five hospitals including Tokyo Medical University completed a comparison trial with newer microwave systems, and wider use is expected | Tokyo Medical University release (December 2024) |
| United Kingdom | NICE supports microwave ablation of hepatocellular carcinoma with normal arrangements for consent and governance; NHS hospitals provide it with patient leaflets | NICE IPG214; King's College Hospital and NNUH leaflets |
| France and Switzerland | University hospitals ran a randomized trial comparing the two procedures | Lancet Gastroenterology & Hepatology 2018 |
International patients are often not covered by the host country's public insurance, so check cost and availability directly with the hospital.
Which procedure is used also depends on the hospital's equipment and the team's experience. For other liver cancer treatments delivered through blood vessels, see our IVR (interventional radiology) guide.
Questions to ask your doctor
- Given my tumor's size and location, is microwave or radiofrequency ablation more suitable?
- My tumor is close to a large vessel, bile duct or the gallbladder. How is that taken into account?
- Which device does this hospital use, and how many procedures does it perform each year?
- If local progression occurs, can it be ablated again, or would I move to another treatment?
To prepare for your consultation, see also five questions to ask before RFA.
Frequently asked questions
Is microwave ablation always better than RFA?
In the Japanese trial of 236 patients, two-year local progression was lower with microwave ablation (16.4% vs 30.4%), while overall survival was similar. In the French–Swiss trial, local progression was low with both. The right choice depends on tumor location and liver function, so decide together with your doctors.
How long is the hospital stay after microwave ablation?
UK hospital leaflets say most patients stay one night and go home the next day if there are no problems. Most return to daily activities within about a week, but heavy lifting and strenuous exercise should be avoided for one to two weeks.
How large a tumor can be treated?
Both comparison trials included tumors up to 4 cm. Larger tumors are sometimes treated in combination with other therapies such as embolization, and suitability is decided by each hospital.
Should I worry about a fever after the procedure?
About 1 in 4 patients develop a mild fever and flu-like feeling two to three days after the procedure, which usually settles within two to three days. Contact your care team promptly if the fever rises suddenly or you have severe abdominal pain.
This article summarizes overseas official sources and research for general information and is not medical advice. Please discuss treatment choices with doctors who have examined the patient.
Sources (checked October 23, 2026)
- Sugimoto K, et al. Microwave ablation vs. single-needle radiofrequency ablation for the treatment of HCC up to 4 cm: A randomized-controlled trial. JHEP Reports. 2025;7(1):101269. doi:10.1016/j.jhepr.2024.101269
- Tokyo Medical University press release (December 23, 2024). Usefulness of microwave ablation in liver cancer: multicenter randomized trial of newer-generation microwave vs radiofrequency ablation (Japanese)
- Vietti Violi N, et al. Efficacy of microwave ablation versus radiofrequency ablation for the treatment of hepatocellular carcinoma in patients with chronic liver disease: a randomised controlled phase 2 trial. The Lancet Gastroenterology & Hepatology. 2018. (NCT02859753)
- NICE. Microwave ablation of hepatocellular carcinoma (IPG214)
- King's College Hospital NHS Foundation Trust (October 2025). CT guided microwave ablation of liver tumours
- Norfolk and Norwich University Hospitals. Radiofrequency (RFA) / microwave ablation for liver cancer