Transcatheter arterial chemoembolization (TACE) is a minimally invasive procedure performed in

interventional radiology Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs bo ...

to restrict a

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

's blood supply. Small

embolic An embolism is the lodging of an embolus, a blockage-causing piece of material, inside a blood vessel. The embolus may be a blood clot (thrombus), a fat globule (fat embolism), a bubble of air or other gas (gas embolism), amniotic fluid (amnioti ...

particles coated with

chemotherapeutic drugs Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...

are injected selectively through a catheter into an

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pul ...

directly supplying the tumor. These particles both block the blood supply and induce

cytotoxicity Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells ...

, attacking the tumor in several ways. The radiotherapeutic analogue (combining

radiotherapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

with embolization) is called radioembolization or

selective internal radiation therapy Selective internal radiation therapy (SIRT), also known as transarterial radioembolization (TARE), radioembolization or intra-arterial microbrachytherapy is a form of radiation therapy used in interventional radiology to treat cancer. It is general ...

(SIRT).

Principles

TACE derives its beneficial effect by two primary mechanisms. Most tumors within the liver are supplied by the

proper hepatic artery The hepatic artery proper (also proper hepatic artery) is the artery that supplies the liver and gallbladder. It raises from the common hepatic artery, a branch of the celiac artery. Structure The hepatic artery proper arises from the common h ...

, so arterial embolization preferentially interrupts the tumor's blood supply and stalls growth until neovascularization. Secondly, focused administration of chemotherapy allows for delivery of a higher dose to the tissue while simultaneously reducing systemic exposure, which is typically the dose-limiting factor. This effect is potentiated by the fact that the chemotherapeutic drug is not washed out from the tumor vascular bed by blood flow after embolization. Effectively, this results in a higher concentration of drug to be in contact with the tumor for a longer period of time. Park et al. conceptualized carcinogenesis of

hepatocellular carcinoma Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide. It occurs in t ...

(HCC) as a multistep process involving parenchymal arterialization, sinusoidal capillarization, and development of unpaired arteries (a vital component of tumor

angiogenesis Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting ...

). All these events lead to a gradual shift in tumor blood supply from portal to arterial circulation. This concept has been validated using dynamic imaging modalities by various investigators. Sigurdson et al. demonstrated that, when an agent was infused via the hepatic artery, intratumoral concentrations were ten times greater compared to when agents were administered through the portal vein. Hence, arterial treatment targets the tumor while normal liver is relatively spared. Embolization induces ischemic necrosis of tumor causing a failure of the transmembrane pump, resulting in a greater absorption of cytotoxic agents by the tumor cells. Tissue concentration of agents within the tumor is greater than 40 times that of the surrounding normal liver.

Therapeutic applications

Transcatheter arterial chemoembolization has most widely been applied to hepatocellular carcinoma for patients who are not eligible for surgery. TACE has been shown to increase survival in patients with intermediate HCC by BCLC criteria. It has also been used as an alternative to surgery for resectable early stage HCC and in patients with regional recurrence of the tumor after previous resection. TACE may also be used to downstage HCC in patients who exceed the

Milan criteria In transplantation medicine, the Milan criteria are set of criteria applied in consideration of patients with cirrhosis and hepatocellular carcinoma (HCC) for liver transplantation with intent to cure their disease. Their significance derives from ...

for

liver transplantation Liver transplantation or hepatic transplantation is the replacement of a diseased liver with the healthy liver from another person (allograft). Liver transplantation is a treatment option for end-stage liver disease and acute liver failure, al ...

. Other treated malignancies include neuroendocrine tumors,

ocular melanoma Uveal melanoma is a type of eye cancer in the uvea of the eye. It is traditionally classed as originating in the iris, choroid, and ciliary body, but can also be divided into class I (low metastatic risk) and class II (high metastatic risk). Symp ...

cholangiocarcinoma Cholangiocarcinoma, also known as bile duct cancer, is a type of cancer that forms in the bile ducts. Symptoms of cholangiocarcinoma may include abdominal pain, yellowish skin, weight loss, generalized itching, and fever. Light colored stool ...

, and

sarcoma A sarcoma is a malignant tumor, a type of cancer that arises from transformed cells of mesenchymal (connective tissue) origin. Connective tissue is a broad term that includes bone, cartilage, fat, vascular, or hematopoietic tissues, and sarcom ...

. Transcatheter arterial chemoembolization plays a

palliative Palliative care (derived from the Latin root , or 'to cloak') is an interdisciplinary medical caregiving approach aimed at optimizing quality of life and mitigating suffering among people with serious, complex, and often terminal illnesses. Wit ...

role in patients with metastatic colon carcinoma. There is a possible benefit for liver-dominant

metastases Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...

from other primary malignancies.

Procedure

TACE is an

procedure performed in the angiography suite. The procedure involves gaining percutaneous transarterial access by the

Seldinger technique The Seldinger technique, also known as Seldinger wire technique, is a medical procedure to obtain safe access to blood vessels and other hollow organs. It is named after Sven Ivar Seldinger (1921–1998), a Swedish radiologist who introduced th ...

to the hepatic artery with an arterial sheath, usually by puncturing the

common femoral artery The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the fem ...

in the right groin and passing a catheter guided by a wire through the

abdominal aorta In human anatomy, the abdominal aorta is the largest artery in the abdominal cavity. As part of the aorta, it is a direct continuation of the descending aorta (of the thorax). Structure The abdominal aorta begins at the level of the thoracic d ...

, through the

celiac trunk The celiac () artery (also spelled ''coeliac''), also known as the celiac trunk or truncus coeliacus, is the first major branch of the abdominal aorta. It is about 1.25 cm in length. Branching from the aorta at thoracic vertebra 12 (T12) i ...

and

common hepatic artery The common hepatic artery is a short blood vessel that supplies oxygenated blood to the liver, pylorus of the stomach, duodenum, pancreas, and gallbladder. It arises from the celiac artery and has the following branches: Additional images ...

, and finally into the branch of the

supplying the tumor. The

interventional radiologist Interventional radiology (IR) is a medical specialty that performs various minimally-invasive procedures using medical imaging guidance, such as x-ray fluoroscopy, computed tomography, magnetic resonance imaging, or ultrasound. IR performs bo ...

then performs a selective angiogram of the

and possibly the superior mesenteric artery to identify the branches of the hepatic artery supplying the tumor(s) and threads smaller, more selective catheters into these branches. This is done to maximize the amount of the chemotherapeutic dose that is directed to the tumor and minimize the amount of the chemotherapeutic agent that could damage the normal liver tissue. When a blood vessel supplying the tumor has been selected, alternating doses of the chemotherapy dose and of embolic particles, or an infusion of embolic particles containing the chemotherapy agent, are injected through the catheter. The physician removes the catheter and access sheath, applying pressure to the entry site to prevent bleeding. The patient must lie stationary for several hours after the procedure to allow the punctured artery to heal. The clinician can apply pressure using a Femostop or close the artery using a vascular sealing device. The patient will often be kept overnight for observation and will likely be discharged the following day. The procedure is normally followed up with a

CT scan A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

several weeks later to check the response of the tumor to the procedure.

Agents

Lipiodol – mixed with chemotherapeutic agents (Lipiodol is nonocclusive, combined with Gelfoam, Ivalon, or other particles) Drug eluting particles – slow, sustained release of loaded drug locally with embolic effect leading to tumor ischemia * Polyvinyl alcohol microspheres – loaded with doxorubicin * Superabsorbent polymer microspheres – loaded with doxorubicin * Gelatin microspheres – loaded with cisplatin EmboCept S - made up of Degradable Starch Microspheres (DSM). It can be mixed with low volume chemotherapeutic agents such as Doxorubicin and

Mitomycin The mitomycins are a family of aziridine-containing natural products isolated from ''Streptomyces caespitosus'' or ''Streptomyces lavendulae.'' They include mitomycin A, mitomycin B, and mitomycin C. When the name mitomycin occurs alone, it usually ...

and high volume chemotherapeutic agents such as Cisplatin and