Minimally invasive interventional radiology therapies for liver cancer

At a Glance:

What are the interventional radiology therapies for liver cancer?

Cancers that are inoperable and expose the patient to high risk for surgical excision can still be cured. For such patients, several minimally invasive interventional radiology procedures are now available for cancer care. These treatments work on a minimally invasive strategy to completely dissolve or destroy the tumor from the designated area without affecting the surrounding tissues.

Cancer treatments by interventional radiologists comprise two treatment methods, supportive/symptomatic treatments, and disease-modifying treatments.

Curative treatments

• Radiofrequency ablation (RFA)
• Microwave ablation
• Ethanol injection

Disease-modifying treatments

• Transarterial chemoembolization (TACE)
• Transarterial radioembolization (TARE)

Supportive/Symptomatic treatments

• Biliary drainage and stenting (PTBD)
• Neo-adjuvant embolization. For example, Portal vein embolization.

How is it used?

•       Performed alone for non-surgical tumors or with non-surgical candidates such as the frail elderly
•       Used as in addition to surgery, chemotherapy, or radiation
•       Performed as a curative therapy
•       Utilized as palliative therapy to shrink tumors to alleviate pain and improve quality of life

How do they work?

The interventional radiologist, along with a team of imaging nurses and technologists, uses an imaging technology – usually a CT, ultrasound or fluoroscopy – to locate a tumor. Once the image of the tumor and its location is available, the interventional radiologist uses the images to guide a catheter or a specialized needle-like probe through the skin into a small tumor. Through the catheter or the probe, treatment is then applied to the tumor. In the case of chemoembolization, a chemotherapy medication is injected into the tumor; with radioembolization, small radioactive spheres are placed to deliver localized radiation therapy; microwave ablation uses microwaves to heat the tumor; and in cryoablation, cold is used to freeze the tumor. In each of these cases, the tumor is directly targeted, leaving most of the surrounding healthy tissue intact. 

What is the interventional ablation (RF and microwave) of tumors and how is it helpful in treating liver cancers?

Surgically untreatable liver tumors can be treated by ablation using radiofrequency waves or microwaves. In this technique liver cancers, including hepatocellular carcinoma and liver metastases that are less than 5 cm can be ablated. In patients with large lesions or multiple lesions, staged treatments can be done using a combination of TACE and RFA (or microwave ablation).

In interventional radiology, radiofrequency tumor ablation is a non-surgical, image-guided, minimally invasive treatment. The interventional radiologist moves a needle-like catheter into the target tumor, then shrinks or destroys the tumor completely with radiofrequency waves.

What is TransArterial ChemoEmbolization (TACE) and how is it helpful in treating liver cancers?

It is selective, localized chemotherapy injected into the liver blood vessel supplying the tumor. The chemotherapeutic agent is mixed with either iodized oil or microbeads and injected into the tumor circulation. The procedure makes sure that the maximum chemotherapy agent is targeted to the tumor while avoiding side effects on the body. After the procedure, the tumor shrinks in size or stabilized thereby prolonging the survival of the patient.

It is a viable and valuable therapeutic option for focal primary and secondary hepatic malignancies such as hepatocellular carcinoma (HCC). For hepatocellular carcinoma, though liver transplantation is the standard treatment, a large number of patients remain unqualified for liver transplantation.

What is TransArterial RadioEmbolization (TARE) and how is it helpful in treating liver cancers?

Transarterial radioembolization (TARE) or selective internal radiotherapy (SIRT) is a relatively new form of local therapy available for different types of liver cancer. It is palliative, not a curative treatment. This means the patients may benefit from extended life expectancy and improved quality of life.

In this procedure, small particles (microspheres) containing 90-yttrium, a radioactive material are injected into the liver blood vessel (hepatic artery) through a small catheter inserted through the patient’s groin under local anesthesia. The internal radiation therapy in the form of microspheres is delivered to the tumor through a catheter placed in the hepatic artery. Once infused, the microsphere lodge in the blood vessels near the tumor where they give off small amounts of radiation to the tumor site for several days. The radiation travels very short distance so its effects are limited mainly to the tumor alone.

TARE is done for patients with locally advanced liver cancer who are otherwise not suitable candidates for liver resection or liver transplantation. Liver tumors treated with TARE are:

• Hepatocellular carcinoma (HCC) stage B & C: TARE can be performed in isolation or as a bridge to transplant in specific case scenarios such as HCC with portal vein thrombosis, large inoperable HCC, HCC with borderline liver function and multicentric HCC.
• Intrahepatic cholangiocarcinoma (ICC)
• Neuroendocrine liver metastasis
• Colorectal liver metastasis

What is portal vein embolization and how is it helpful in treating liver cancers?

Portal vein embolization is a technique used before liver resection to increase the size of liver segments that will remain after surgery. This therapy redirects portal blood to segments of the Future Liver Remnant (FLR), resulting in hypertrophy. It is indicated when the FLR is either too small to support essential function or marginal in size and associated with a complicated postoperative course.

When appropriately applied, PVE has been shown to reduce postoperative morbidity and increase the number of patients eligible for curative-intent resection.

What is PTBD and how is it helpful in treating liver cancers?

Percutaneous transhepatic biliary drainage (PTBD) is a procedure to drain the bile ducts in the presence of a blockage or damage that prevents normal bile drainage. Using fluoroscopy (live x-ray), a needle is guided into the bile ducts, where a contrast agent is injected to allow visualization on the monitor. A catheter is placed into the bile duct to allow the bile to drain out into a bag outside the body. To prevent further drainage difficulties, a stent may be placed in a blocked or restricted bile duct to hold it open and allow bile to flow freely. PTBD is indicated in obstructive jaundice caused due to obstruction of bile ducts, and cancers of the bile duct, the pancreatic head, the gallbladder, the stomach or the lymph nodes.

What are the benefits of these minimally invasive procedures over traditional surgical resection?

Possible advantages of minimally invasive therapies compared to surgical resection include the anticipated reduction in complications and deatlhs, lower cost. These procedures do not require hospitalization and can be performed on outpatients, and potentially applied in a wider spectrum of patients, including patients not eligible for surgeries. 

Compared to conventional standard surgical resection, interventional tumor embolization causes minimal amount of normal tissue loss. For example, in primary liver tumors, the long-term survival outcomes for the patients is dependent on the functional hepatic reserve and image-guided tumor ablation therapies have documented success in minimizing damage to cirrhotic liver cells around the focal malignancies.

What are the benefits for the patients?

Interventional therapy requires less anesthesia, causes less trauma and pain, and patients have shorter hospital stays and recover more quickly over open surgery. Some other benefits for the patients are –

•      Viable option when surgery or radiation are not options
• Usually performed with minimal sedation
•      Requires a shorter hospital stay and recovery time
•      Minimal risk of infection or blood loss
•      Less trauma to adjacent tissues
•      Low complication rate
•      Sessions may be repeated if new tumors develop
•      Used along other cancer treatments – chemotherapy or liver transplantation
•      Pain relief

Are you eligible for interventional therapies for liver cancer?

Optimal cancer care is provided by a team approach that includes the interventional radiologist oncologist and primary care physician. To find out if you might be a candidate for one of these procedures, please request a callback.

How do I get ready for the interventional procedure – TACE or TARE?

These interventional procedures are performed during sedation therefore, you should not eat or drink anything after midnight on the night beforehand, but you may drink water up to two hours before the procedure. The attending doctor will give more specific instructions about which medications you may take in the morning. You may stay at the hospital overnight so bring what you will need for your stay at the appointment.

How is the recovery after the procedure?

Once the procedure is complete you will be moved to the ward where your vital signs will be monitored for the first two to three hours. In some cases not all, patients stay in the hospital overnight. We advise that for 24 hours following the procedure, you avoid driving and exercising strenuously. In a few days after discharge you will be asked to return for follow-up imaging tests, and if the tumor has not shrunk, you may need additional treatment. You should be able to resume your usual activities within a few days.

About Author –

Dr. Suresh Giragani, Consultant Neuro & Interventional Radiologist, Yashoda Hospitals – Hyderabad
MD (Radiology), DM (Neuroradiology)

Specialized in the comprehensive and widest range of vascular interventions covering neuro interventions, hepatobiliary interventions, venous, peripheral vascular interventions and interventions in cancer care.