Treatment of primary liver tumors

TACE Transarterial chemoembolization (TACE) for liver cancer

Embolization is a treatment that blocks or slows down the blood supply to tissues or an organ. It can be used to block the flow of blood to a tumour so the cancer cells die. When the material used to block the blood supply also delivers chemotherapy drugs to the tumour, it is called chemoembolization. Transarterial chemoembolization (TACE) is a specific type of chemoembolization that blocks the hepatic artery to treat liver cancer.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. This type of tumour grows a large number of blood vessels. These blood vessels get most of their blood supply from the hepatic artery, while the rest of the liver tissue gets blood from the portal vein. Because of this, doctors can block the hepatic artery to cut off the blood supply to the tumour without affecting the rest of the liver.

The healthcare team will only offer TACE if you have good liver function, you don’t have any fluid in your abdomen (called ascites) and there are no problems with the portal vein in your liver. TACE may be used if your liver cancer can’t be removed with surgery but it hasn’t spread to the major blood vessels in the liver, lymph nodes or other parts of the body. You may also be offered TACE to keep a liver tumour small if you are waiting for a liver transplant (called “bridging” therapy).

Doctors may offer TACE to treat liver tumours that are larger than 5 cm, but it may take 2 or 3 treatments to shrink these tumours. If cancer is in both lobes of the liver, doctors will treat one lobe at a time. Treatment to each lobe is usually given a month apart so that you have time to recover from the first TACE treatment.

How TACE is done

TACE is done in the x-ray department of a hospital. You may be given a local anestheticwith a drug to help you relax, or you may be given a general anesthetic to put you to sleep.

The doctor places a thin tube (called a catheter) into the large blood vessel in your groin (called the femoral artery). The doctor then moves the catheter up through the artery until it reaches the hepatic artery in the liver. A radio-opaque dye is injected into the catheter and an x-ray is taken to find the branches of the artery that are feeding the liver tumour (called an angiogram). The doctor then moves the catheter to these arteries. The doctor injects a material into the arteries feeding the tumour. The material blocks these arteries. Some types of blocking material dissolve so the arteries are not permanently blocked.

The most commonly used material for TACE is a gelatin sponge. Sometimes the gelatin sponge is soaked in a chemotherapy drug and an oily liquid called lipiodol before the doctor injects it into the artery. The sponge traps the chemotherapy drugs inside the liver so that they are concentrated in the area of the tumours. Lipiodol lengthens the amount of time that the drugs are held in the liver. If the chemotherapy drugs are not in the sponge, they are injected into the arteries after they are blocked.

DEB-TACE is a new way of delivering chemotherapy during TACE. It uses special beads that already have the chemotherapy drug in them (called drug-eluting beads, or DEBs). After these beads are injected into the arteries in the liver, they slowly release the drug to treat the tumour. These drug-eluting beads are as effective as using the sponge or injecting chemotherapy drugs in the arteries. DEB-TACE may have fewer side effects than the other methods.

If the cancer is in only one lobe of the liver, doctors may give a small amount of chemotherapy to the other lobe to treat any tumours that might be in it.

After the chemoembolization is done, the doctor pulls the catheter out through the femoral artery. Pressure and ice are placed over the incision to help reduce swelling and stop bleeding.

 

Chemotherapy drugs used in TACE

There are no standard recommended chemotherapy drugs for TACE. The drugs that may be used alone or together are:

doxorubicin (Adriamycin)

cisplatin (Platinol AQ)

mitomycin (Mutamycin)

Follow-up after TACE

You may have a CT scan 2 or 3 months after TACE. Doctors use this imaging test to see how much the tumours have shrunk and to look for any new tumours in the liver.

Many people will need another TACE procedure because liver tumours often grow back in 10–16 months. TACE can be repeated as many times as needed, as long as you are still healthy enough to have it done.

 

Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Liver Tumors

Radiofrequency ablation (RFA) and microwave ablation (MWA) are treatments that use image guidance to place a needle through the skin into a liver tumor. In RFA, high-frequency electrical currents are passed through an electrode in the needle, creating a small region of heat. In MWA, microwaves are created from the needle to create a small region of heat. The heat destroys the liver cancer cells. RFA and MWA are effective treatment options for patients who might have difficulty with surgery or those whose tumors are less than one and a half inches in diameter. The success rate for completely eliminating small liver tumors is greater than 85 percent.

What are Radiofrequency and Microwave Ablation of Liver Tumors?

Radiofrequency ablation, sometimes referred to as RFA, is a minimally invasive treatment for cancer. It is an image-guided technique that uses heat to destroy cancer cells. It uses imaging techniques such as ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) to help guide a needle electrode into a cancerous tumor. High-frequency electrical currents are then passed through the electrode to ground pads placed on the body, creating focal heat that destroys the cancer cells surrounding the electrode.

Microwave ablation (MWA) is also a minimally-invasive treatment for cancer. MWA also uses ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) to guide placement of a specialized needle-like probe into a tumor. MWA uses microwaves to heat and destroy the tumor and is used for the same indications as RFA. The procedure is typically performed on an outpatient basis or with overnight observation in the hospital with general anesthesia. For the patient, MWA offers low risk and a short hospital stay. Ablation can be used to treat multiple tumors simultaneously. The procedure can be repeated if new cancer appears.

 

How is the procedure performed?

General anesthesia is used, you will have a breathing tube placed through your mouth and into your trachea after you are asleep. The breathing tube will be connected to a breathing machine while you are asleep.

Using imaging-guidance, your physician will insert the needle electrode through the skin and advance it to the site of the tumor.

Once the needle electrode is in place, energy is applied. For a large tumor, it may be necessary to do multiple ablations by repositioning the needle electrode or by placing multiple needles into different parts of the tumor to ensure no tumor tissue is left behind.

At the end of the procedure, the needle electrode will be removed and pressure will be applied to stop any bleeding and the opening in the skin is covered with a dressing. No sutures are needed.

Each ablation takes about 10 to 30 minutes, with additional time required if multiple ablations are performed. The entire procedure is usually completed within one to three hours.