Microwave ablation

Microwave ablation is a type of tumor ablation. We guide a thin needle, called an antenna, through the skin into the tumor. The antenna gives off microwave energy that makes water molecules in the tissue vibrate and heat up, well above 60°C (140°F). At that temperature, tumor cells die within minutes.

Microwaves heat quickly and evenly, and they are less cooled by nearby blood vessels than older radiofrequency ablation (RFA). That means larger, more reliable treatment zones in less time. The treated tumor stays in place and slowly shrinks into a scar over months.

On CT or ultrasound, the antenna shows as a bright line through the tumor. After heating, the treated zone looks like a dark, rounded area that should be larger than the original tumor on every side.

For small tumors in the right spot, microwave ablation can control the tumor about as well as surgery in many studies, with an easier recovery. Surgery may still be better for some tumors, and the chance of the tumor coming back at the edge is a little higher after ablation. Other options include cryoablation, histotripsy, and for liver tumors, chemoembolization or Y-90 radioembolization, sometimes combined with ablation.

1. 1
   Getting ready

   The procedure is done at El Camino Hospital. You receive moderate sedation or general anesthesia and lie on the CT table. We clean and numb the skin.

2. 2
   Placing the antenna

   Using CT or ultrasound, we guide the antenna into the tumor. If bowel or another organ is close, we may inject fluid to push it safely away.

3. 3
   Heating

   We switch on the microwave energy, usually for 5–10 minutes per tumor. Several tumors can be treated in one session.

4. 4
   Checking and finishing

   A contrast CT confirms the treated zone covers the tumor with a margin. We heat the needle path as the antenna comes out, then place a small bandage.

1. First few hours
   You rest in recovery. You can eat and drink once awake. After a lung treatment, a chest X-ray checks the lung.
2. Day 1
   Many people go home the same day, others the next morning. No driving for 24 hours after sedation.
3. Days 2–10
   Soreness should improve each day. About a third of people get post-ablation syndrome: low fever, aches and tiredness, starting a few days after and lasting up to about a week or so.
4. About 1 week
   Most people are back to usual activities. We see you to check how you are healing.
5. About 4–6 weeks
   A CT or MRI confirms the tumor was fully treated, then scans every few months.

For liver tumors 3 cm or smaller, most are destroyed completely with one treatment. Larger tumors are more likely to come back at the edge. If a tumor recurs, ablation can often be repeated.

With microwave ablation, success is decided by the margin, the ring of normal tissue we destroy around the tumor. I plan the needle path on the CT beforehand and check the treated zone with contrast before you leave the table, so if any edge looks thin I can add more heat right then. I also tell patients the follow-up scans are part of the treatment, not an afterthought.

Fabio Komlos, MD, interventional radiologist · About Dr. Fabio Komlos