Liver-directed therapy

Liver-directed therapies (LDTs) are typically used to target cancers that have spread to the liver—especially those that aren’t good candidates for surgery, either because they’re hard to remove or because the patient isn’t healthy enough to withstand an operation.

LDTs administer medications or therapies, or perform destructive procedures, directly in the tumors in the liver. This forges a direct route, instead of injecting medicine into a vein, for example, and having it spread throughout your whole body.

The goal of liver-directed therapies is to damage the cancer cells enough that the tumor stops growing and shrinks. This helps reduce symptoms and potentially makes the tumor more amenable to surgery.

Types of liver-directed therapy

Doctors may conduct liver-directed therapies in several ways.

Embolization procedures: Embolization is a procedure that blocks blood from getting to the tumor. It may be done because the liver has two sources of blood: the portal vein and the hepatic artery. Most healthy, normal liver tissue may be fed with blood from the portal vein, but tumors often feed off the blood in the hepatic artery.

This therapy typically involves the use of beads that fill up and cut off blood flow to the smaller vessels feeding the tumor. Sometimes, the hepatic artery itself is blocked as well. The blockage slows blood flow to the tumor, starving it of nutrients and oxygen, shrinking and damaging the cancer.

This procedure may be used for larger tumors as well, but only if the patient has normal liver function.

In addition to starving the tumor, the beads themselves may be augmented with cancer treatments to selectively deliver these treatments to the cancer cells.

• Chemoembolization either pumps chemotherapy drugs into the liver before the blood flow is blocked, or it adds chemotherapy medications to the beads used to block blood flow. Either way, the aim is to keep these toxic medications near the cancer cells, killing them.
• Radioembolization infuses the beads with radiation, which damages the tumor’s tissues, usually using a radioactive element called yttrium-90 packed into tiny microspheres, sometimes called SIR-Spheres®. Millions of these radioactive spheres are inserted into the liver tumor to destroy the cancer.

Ablation procedures: Ablation therapies aim to damage or destroy the cancer cells directly, but leave them inside the liver. They use either heat (radiofrequency), cold (cryotherapy) or microwaves to get this job done. Another option is ethanol ablation, also known as percutaneous ethanol injection (PEI), which injects the concentrated chemical ethanol into the tumor to kill it. Ablation techniques are used when there’s a clear number of tumors to be destroyed that are no more than a few centimeters wide.

Hepatic arterial infusion (HAI): This procedure implants a pump that delivers high-dose chemotherapy directly to the liver, bypassing the rest of the body, with the hope of limiting or reducing side effects of the chemotherapy. It’s useful for large tumors that other liver-directed therapies may not be able to tackle.

The liver is a special organ because it makes tons of different enzymes that work to disable and destroy toxic substances. That includes medicines like chemotherapy, so chemotherapy applied directly (and only) to the liver can be dosed at much higher levels without causing as many side effects as systemic treatments.

How to prepare for liver-directed therapy

• Ask your doctor what treatment day may look like for you, because it varies widely with the procedure used and the tumor.
• Before any procedure, abstain from eating and drinking for several hours.
• If you’re doing an outpatient procedure, you’ll likely be given a local anesthetic to numb the skin where they’ll make a few small cuts. An HAI procedure may require general anesthesia (being put to sleep for surgery) for placement of the pump used to deliver chemotherapy.
• In most cases, these procedures may be done in outpatient clinics, and you’ll be ready to return home the same day, as long as there are no complications. Make sure you have a ride home set up.

During ablative therapy, they’ll usually monitor the needle’s position with computed tomography (CT) scans, X-rays or an ultrasound to ensure the treatment is being done in the appropriate area of the liver.

The length of the procedure varies based on how many tumors need to be treated.

In the days following treatment, you’ll likely feel pain and discomfort and potentially experience additional side effects. Allow your body time to heal.

Risks of liver-directed therapy

Various approaches to liver-directed therapies have a number of side effects to watch out for. As these treatments all affect the liver, known side effects are similar.

All of the LDTs mentioned above have a risk of:

• Abdominal pain or discomfort
• Low fever
• Fatigue

It’s possible you may experience:

• Bleeding
• Infection
• Abscess
• Skin burn
• Injury to bile duct

It may take more than a month to recover from an embolization procedure. There’s also the risk of damaging healthy liver tissue or developing postembolization syndrome, which includes:

• Nausea and vomiting
• Extreme fatigue
• Carcinoid crisis, a potentially life-threatening reaction due to molecules put out by the damaged tumor

Hepatic arterial infusions, while less likely to cause extreme chemotherapy side effects, have possible complications of their own. Along with some of the other symptoms mentioned above, the HAI procedure may result in the development of stomach ulcers and hardening of the bile duct.

Liver-directed therapy results

A few weeks after treatment, your doctor will likely want to see what the tumor looks like. Your doctor may order a CT scan or magnetic resonance imaging (MRI) to see inside your body. This imaging may be repeated in a few months as well.

Your liver-directed therapy may be followed by surgery or other cancer treatments.