Chemoembolization - Uses, Procedure, Preparation, Side Effects, and Limitation

Introduction:

Chemoembolization, also known as transarterial chemoembolization (TACE), combines the local delivery of high doses of cancer-killing drugs directly into the tumor (chemotherapy) and blocks the blood vessels supplying the tumor. Chemoembolization is a treatment option for patients with liver cancer who cannot be treated by surgery. Chemoembolization is a palliative (relieving the symptoms without dealing with the cause), not a curative treatment.

The liver has its blood supply from an artery (hepatic artery) and a large vein (portal vein). The normal liver cells receive about 75 percent of their blood supply from the portal vein and 25 percent of their blood supply from the hepatic artery. Tumor in the liver receives most of their nutrients and oxygen through the hepatic artery. Anti-cancer drugs are injected into the hepatic artery, which affects the tumor cells and spares the healthy liver cells. When the embolization (blocking the artery) is done, the normal liver cells receive blood supply from the portal vein.

What Are the Uses of Chemoembolization?

Chemoembolization is useful for treating only liver cancer. It is ineffective in treating cancer in other parts of the body. Chemoembolization is used to treat the following liver cancer:

• Hepatoma (cancer originates in the liver).

• Cholangiocarcinoma (cancer originates from the bile ducts).

• Metastasis (cancer spreading to different parts of the body from its initial site) to the liver from the following:

  • Colon cancer.

  • Sarcomas (cancer begins in bone and soft tissues such as muscle, blood vessels, fat, cartilage, etc).

  • Breast cancer.

  • Islet cell tumors of the pancreas.

  • Ocular melanoma (a type of eye cancer that develops in the cell producing melanin pigments).

  • Carcinoid tumors (slow-growing tumors that arise in several parts of the body) and other neuroendocrine tumors (cancer develops from the neuroendocrine system).

  • Other vascular primary tumors (tumors arising from blood vessels or lymph vessels) in the body.

What Are the Agents Used in Chemoembolization?

Embolization is a medical procedure that uses gelatin sponges or beads (embolic agents) to block the blood vessels. Embolic agents commonly used in chemoembolization procedures are:

• Polyvinyl Alcohol Microspheres - Loaded with Doxorubicin.

• Super Absorbent Polymer Microspheres - Loaded with Doxorubicin.

• Gelatin Microspheres - Loaded with Cisplatin.

How Do You Prepare for the Chemoembolization Procedure?

• You should not eat or drink beverages for at least six hours before the procedure.

• You can drink water two hours before the procedure.

• Inform your doctor about your medical conditions and your regular medicines.

• You may be asked by the doctor to stop taking antiplatelet drugs (drugs that reduce platelet aggregation), blood thinners, or nonsteroidal anti-inflammatory drugs (NSAIDs).

• Before the procedure, you may be asked to take a blood test to check your kidney function and to determine whether your blood clots normally.

• Tell your doctor if you are allergic to local or general anesthesia or contrast materials and if you are pregnant or suspect being pregnant. Radiation exposure in pregnant women may cause birth defects to the fetus in the womb.

• Children are at increased risk of blood clots at the entry site of the tube because of the small size of blood vessels.

How Is Chemoembolization Done?

• Chemoembolization is usually done by a specialized doctor called an interventional radiologist. During the procedure, you are asked to lie on the procedure table.

• Then, the nurse or doctor will insert an intravenous (IV) line into your hand to deliver the sedative to make you feel relaxed and sleepy. This procedure requires moderate sedation. Children may require general anesthesia to help them hold in place and be comfortable during the procedure. You might be given a medicine called Allopurinol before the procedure, which protects your kidneys from cancer treatment and the end product produced by the dying cancer cells. Your heart rate, BP (blood pressure), oxygen level, and pulse rate will be monitored throughout the procedure.

• After that, the doctor will make a small incision at the site. Under the guidance of X-ray, usually fluoroscopy (X-ray video), they insert a thin tube called a catheter through the skin into the artery in the groin or wrist and advance it to the liver. Contrast material (a special dye) is injected through the tube, and a series of X-ray images will be taken. When the contrast material passes through your body, you may feel warm.

• Once the catheter is placed in the branches of the artery that supplies the tumor, a mixture of anti-cancer medicine and embolic agents is injected. Additional images will be taken to confirm that the entire tumor has been treated.

• Once the procedure is done, your doctor will remove the tube and apply pressure to stop bleeding from the site. Your doctor will use a closure device to seal the small hole in the artery. The incision in the skin will be covered with a dressing. This procedure usually takes about 90 minutes. It may vary sometimes. You may be instructed to stay in the hospital after the procedure between two to six hours. It depends on the type of artery which was accessed.

What Are the Side Effects of the Chemoembolization Procedure?

• You may feel slight pain while inserting an injection into your vein.

• There may be a risk of damage to the blood vessel, bleeding at the puncture site, and infection while placing the catheter inside the blood vessel.

• There might be a chance that embolization material reaches the wrong place and cuts off the blood supply to the normal tissue.

• As this procedure uses contrast material, there might be a chance of allergic reactions to contrast material.

• Even though antibiotics have been given during the procedure, there might be a risk of infection from skin incision after embolization.

• There might be a risk of kidney damage due to the contrast material used in this procedure. This is particularly in diabetic patients and patients with pre-existing kidney disease.

• You may experience some of the post embolization (after embolization) symptoms such as pain, nausea, fever, and tiredness the next day. Medicines can help with these symptoms.

How Effective Is the Chemoembolization Procedure?

You can continue your regular activities within a week of the procedure. During the first month after the procedure, you should have a regular check-up to let your doctor know about your recovery process. The benefit of this procedure usually lasts between ten to 14 months, depending on the type and size of the tumor. In case a new tumor is formed after the procedure, this procedure will be repeated. Computed tomography and magnetic resonance imaging will be performed every three months after the procedure to determine the status and size of the treated tumor and to see if any new tumors arise in the liver after the procedure.

What Are the Limitations of Chemoembolization?

If you have any of the following conditions, you are not recommended to undergo the chemoembolization procedure:

• Liver cirrhosis (a disease in which healthy liver tissue is replaced with scar tissue).

• Blockage of the portal vein.

• Blockage of the bile ducts.

• Severe liver or kidney dysfunction.

Conclusion:

Chemoembolization is the first line of treatment option for large liver cancer that cannot be treated with surgery or ablation. Chemoembolization is also useful in treating advanced lung cancer associated with hemoptysis (coughing up blood). It is effective in treating primary liver cancers, potentially preserving liver function and saving many lives. Chemoembolization has been shown to increase the survival rate in patients with the intermediate stages of liver cancer. It is a palliative treatment option for patients with metastatic colon cancer.