What Is TARE? Why Is It Performed?
The liver is one of the largest internal organs in the body and has more than 500 functions. It carries out vital functions such as removing waste substances present in the body, producing bile and proteins, metabolizing carbohydrates, proteins and fats, blood clotting, and filtering toxins. When various health problems arise in the liver, this can pose a life-threatening risk. Cancer is a condition that can affect the liver and can appear in more than one form. Liver cancer can develop in different types, such as hepatocellular carcinoma, intrahepatic cholangiocarcinoma and hepatoblastoma. In addition, cancer that spreads from another part of the body through metastasis can also affect the liver.
Liver cancer treatment is determined by the patient's general health and the stage of the cancer. Transarterial radioembolization (TARE), an innovative type of treatment, is targeted radiation therapy. Surgical removal of tumors in the liver is commonly performed, but it is not always the only option. Instead, TARE, a minimally invasive treatment option, involves injecting radioactive treatment directly into the blood vessels that supply the tumors. The injection, applied into the hepatic arteries, can directly target the tumor through the bloodstream. Because of the vascular blood supply characteristics of the liver, the likelihood of damaging normal liver tissue is very low. It may be preferred for the treatment of localized or diffuse tumors in the liver.
What Is TARE (Radioembolization)?
Transarterial radioembolization (TARE) is a radiation therapy delivered using Yttrium-90 microspheres. For this reason, it may also be called Y-90 therapy. It is applied to cancers that originate in the liver and to cancers that metastasize to the liver. It is a procedure recommended when liver tumors cannot be removed surgically due to their size or number, and when other local treatments (such as radiofrequency ablation) cannot be applied.
The treatment involves the use of Yttrium-90-loaded glass and resin microspheres for a very wide range of cancers, including hepatocellular carcinoma, intrahepatic cholangiocarcinoma, breast cancer, malignant melanoma, lung cancers, colorectal cancer and neuroendocrine tumors. It may also be preferred to downstage the cancer and as a bridge to liver transplantation. Because liver tumors are fed by the hepatic arteries rather than the portal vein, the microspheres are deposited there. The embolized spheres then begin local radiation irradiation. DNA damage occurs in tumor cells irradiated by Yttrium-90.
Why Is TARE (Radioembolization) Performed?
TARE is typically performed to destroy primary liver cancers and metastatic cancers with radiation. Unlike other cancer treatments, it is a localized procedure that uses high-dose radiation. It helps control cancerous tissue that cannot be removed surgically. Y-90 therapy provides radiation treatment through radioactive spheres delivered into the arteries. The radioactive isotope yttrium-90, placed on microspheres or resin particles at the micro level, is injected into the blood supply of the tumor.
Tumors are fed by these blood vessels, and in this way the microspheres travel to the area where the tumor is located. The radioactive spheres reach the tumors and accumulate there. By emitting radiation at a level that cannot be reached by other methods, they either kill cancer cells directly or cause damage to their genetic code. The growth of the damaged tumor is suppressed and, over time, it begins to die. Meanwhile, treatment can be provided without damaging the surrounding healthy liver tissue, which is fed by the portal vein.
As a result, it supports the shrinking and destruction of tumors that cannot be removed. It can be applied in combination with other cancer treatment methods. In addition, it may be used in patients whose tumors need to be shrunk in order to perform a liver transplant.
How Does the Process Before TARE Proceed?
Routine physical examination and tests are performed before TARE. The patient undergoes blood tests to assess general health, blood clotting, kidney function and liver function. At the same time, medical history and current and previously used medications are reviewed. Herbal supplements, aspirin and blood-thinning medications must be discontinued.
The arteries located in the upper abdomen are visualized with a diagnostic test called angiography. Angiography provides images of the blood vessels feeding the tumor. Identifying the blood vessels that supply the tumor can provide information about where the radioactive microspheres will be placed. Since microspheres will be injected into these blood vessels during the TARE procedure, the area must be mapped. During this process, damage to healthy tissue in the liver can be minimized.
During angiography, a contrast agent is administered into the bloodstream, allowing the blood vessels to be visualized in white. Sedatives and anesthesia are given before the procedure. Local anesthesia applied during catheter placement may cause discomfort, but efforts are made to minimize the pain.
How Long Does TARE Take?
The purpose of TARE and the additional techniques used may affect the duration of the procedure. The application, which usually lasts between 1 and 3 hours, may end earlier or later. As it is an outpatient treatment procedure, discharge can take place on the same day. The procedure begins with angiography, which involves mapping the blood vessels. Access is aimed at the liver arteries through the wrist or groin arteries.
To prevent radioactive microspheres from passing into the stomach and intestines, the blood vessels in these areas may be temporarily occluded with metal coils. A thin catheter is placed in the tumor area. When the catheter reaches the tumor, microspheres are injected into the tumor. When the injection of the radioactive substance is complete, the catheter is removed and pressure is applied to the site for about one hour. The side effects caused by the procedure are limited, but in some cases they may cause discomfort. In this context, your doctor may prescribe medications to alleviate the symptoms.
How Is the TARE Procedure Performed?
The contrast agent given into the blood before the procedure allows imaging with X-rays. Visualization of the blood vessels helps place the microspheres in the appropriate locations. A thin, flexible tube called a catheter is inserted into the arm or thigh artery and advanced toward the hepatic arteries. Microspheres are deposited in the vessels that supply blood flow to the tumor. With the bloodstream, the microspheres reach the tumor and accumulate there. By applying a high dose of radiation, the growth of cancer cells is prevented.
Who Is TARE Performed On?
The cases in which TARE is applied most often include hepatocellular carcinoma, intrahepatic cholangiocarcinoma, neuroendocrine tumors, and various cancers that metastasize to the liver. These cancer types are the conditions that may require the TARE procedure.
What Can Happen After TARE?
Transarterial radioembolization is usually an outpatient treatment procedure. As it is a same-day procedure, the patient can go home on the same day. However, the important point to note is that others should not be exposed to radiation. For several days after treatment, contact or interaction, especially with pregnant women and children, is not recommended. At the same time, you should sleep alone for at least three days and avoid sitting close to others for more than two hours. Side effects that may occur after TARE, such as nausea, vomiting, abdominal pain and fatigue, are evaluated.
The response of the tumor to TARE treatment is monitored with computed tomography (CT), MRI and PET/CT techniques. During the evaluation phase, the signs and symptoms of possible complications are reviewed. Very rare complications such as hepatic abscess (liver abscess), perihepatic ascites (fluid around the liver), radiation cholecystitis (gallbladder inflammation) and pneumonitis, and pleural effusion (fluid accumulation between the layers of the lungs) are evaluated. If abnormal symptoms are present, it is essential to contact a relevant healthcare facility without delay.
Does TARE Carry Any Risks?
Radioembolization is performed in a minimally invasive manner with minimal pain. It is a procedure designed to preserve healthy liver and arterial tissue. However, since the embolization technique partially blocks blood flow to the tissue, the risk of damage may be considered. Nevertheless, given the small particle size and the microembolic effect, it causes fewer side effects than standard radiation therapy.
In the condition known as post-radioembolization syndrome, rare side effects such as fatigue, nausea, vomiting, fever, cachexia, anorexia and abdominal discomfort may occur. Every surgical procedure carries certain risks. However, these serious complications occur less frequently. The risks that TARE may lead to can mainly include:
Hepatobiliary (liver-pancreas) dysfunction,
Inflamed pancreas or liver abscess,
Radiation pneumonitis,
Accumulation of fluid or ascites in the abdomen,
Ulcerations in the gastrointestinal tract,
Vascular injuries,
In addition, in rare cases, allergic reactions related to the angiography procedure and risk of kidney failure may arise.
What Is the Difference Between TARE and Standard Radiotherapy?
TARE is internal radiation therapy. Standard or conventional radiotherapy, on the other hand, is external radiation therapy, also known as external beam radiation. A machine that delivers high-energy rays sends radiation through the skin to the tumor and some of the surrounding tissues. In contrast, in TARE, the very high-energy rays emitted from the microspheres tend to travel only a few millimeters. Because of this feature, while the cancer cells receive a high dose of radiation within the tumor, healthy liver tissue is protected from radioactive effects. TARE may be preferred for patients in whom local control can be achieved and who are not in a life-threatening condition. External radiotherapy may be preferred to relieve symptoms in patients whose condition is poor and whose life expectancy is limited. To determine the most suitable treatment method for you between radiotherapy and TARE, please contact a relevant healthcare facility.
What Are the Differences Between Chemoembolization and Radioembolization?
There are certain differences between Transarterial Radioembolization (TARE) and Transarterial Chemoembolization (TACE). These differences can mainly be listed as follows:
In the TACE procedure, particles loaded with chemotherapeutic agents are injected into the liver. In the TARE procedure, radioactive particles are injected into the blood vessels that supply blood flow to the liver.
TARE may be used in the presence of multiple or large tumors in the liver. TACE is generally effective in small liver tumors.
The TACE procedure is more economical compared to TARE, but its side effects after the procedure may be more severe. Radioembolization side effects are rarer and are generally better tolerated.
Complications caused by TARE are rarely seen, and the risk of serious complications is less than 1%.
TARE may be used as a bridging procedure prior to liver transplantation.
Because TARE radioactive spheres are smaller than those used in TACE, they can be safely used in patients with health problems such as portal vein obstruction, among others.
There is no definitive information about survival rates. TACE may be limited due to tumor volume, whereas TARE can reach tumor cells as confirmed.
