Percutaneous hepatic perfusion | |
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Specialty | Oncology |
Percutaneous hepatic perfusion (PHP) is a regionalized, minimally-invasive approach to cancer treatment [1] currently undergoing Phase II and Phase III clinical testing. PHP treats a variety of hepatic tumors by isolating the liver and exposing the organ to high-dose chemotherapy. As demonstrated in clinical trials, patients treated by PHP can tolerate much higher doses of chemotherapeutic agents than those receiving traditional systemic chemotherapy without increased toxicities.[ citation needed ]
Using a system of catheters and filters, PHP isolates the liver from the circulatory system and infuses a chemotherapeutic agent directly to the liver via the hepatic artery. The venous effluent from the liver is then filtered outside of the body and the filtered blood is returned into the jugular vein. PHP is a repeatable procedure and can be performed in an operating room or a radiology suite under local or general anesthesia.[ citation needed ]
Chemotherapy is the type of cancer treatment that uses one or more anti-cancer drugs in a standard regimen. Chemotherapy may be given with a curative intent, or it may aim only to prolong life or to reduce symptoms. Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called medical oncology.
Liver tumors are abnormal growth of liver cells on or in the liver. Several distinct types of tumors can develop in the liver because the liver is made up of various cell types. Liver tumors can be classified as benign (non-cancerous) or malignant (cancerous) growths. They may be discovered on medical imaging, and the diagnosis is often confirmed with liver biopsy. Signs and symptoms of liver masses vary from being asymptomatic to patients presenting with an abdominal mass, hepatomegaly, abdominal pain, jaundice, or some other liver dysfunction. Treatment varies and is highly specific to the type of liver tumor.
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 both diagnostic and therapeutic procedures through very small incisions or body orifices. Diagnostic IR procedures are those intended to help make a diagnosis or guide further medical treatment, and include image-guided biopsy of a tumor or injection of an imaging contrast agent into a hollow structure, such as a blood vessel or a duct. By contrast, therapeutic IR procedures provide direct treatment—they include catheter-based medicine delivery, medical device placement, and angioplasty of narrowed structures.
Embolization refers to the passage and lodging of an embolus within the bloodstream. It may be of natural origin (pathological), in which sense it is also called embolism, for example a pulmonary embolism; or it may be artificially induced (therapeutic), as a hemostatic treatment for bleeding or as a treatment for some types of cancer by deliberately blocking blood vessels to starve the tumor cells.
Transcatheter arterial chemoembolization (TACE) is a minimally invasive procedure performed in interventional radiology to restrict a tumor's blood supply. Small embolic particles coated with chemotherapeutic drugs are injected selectively through a catheter into an artery directly supplying the tumor. These particles both block the blood supply and induce cytotoxicity, attacking the tumor in several ways.
Docetaxel, sold under the brand name Taxotere among others, is a chemotherapy medication used to treat a number of types of cancer. This includes breast cancer, head and neck cancer, stomach cancer, prostate cancer and non-small-cell lung cancer. It may be used by itself or along with other chemotherapy medication. It is given by slow injection into a vein.
Transjugular intrahepatic portosystemic shunt is an artificial channel within the liver that establishes communication between the inflow portal vein and the outflow hepatic vein. It is used to treat portal hypertension which frequently leads to intestinal bleeding, life-threatening esophageal bleeding and the buildup of fluid within the abdomen (ascites).
Delcath Systems, Inc. is a publicly traded specialty pharmaceutical and medical device company, that develops percutaneous perfusion technologies for the targeted administration of high-dose chemotherapeutic agents to specific organs or regions of the body. Based in Queensbury, New York, the company has an intellectual property portfolio consisting of 28 patents worldwide. Delcath's Percutaneous Hepatic Perfusion (PHP) is currently undergoing Phase II and Phase III trials against tumors in the liver. Delcath has a Cooperative Research and Development Agreement (CRADA) with the National Cancer Institute and has received Fast Track and a Special Protocol Assessment from the Food and Drug Administration for its use of melphalan in treating unresectable liver tumors. PHP, also known as the Delcath System, is tested for the treatment of metastatic melanoma in the liver and for primary liver cancer and metastatic hepatic malignancies from neuroendocrine cancers and adenocarcinomas, as well as patients with melanoma who previously received isolated perfusion. Chemotherapy is usually delivered intravenously, although a number of agents can be administered orally.
Hepatic arterial infusion (HAI) is a medical procedure that delivers chemotherapy directly to the liver. The procedure, mostly used in combination with systemic chemotherapy, plays a role in the treatment of liver metastases in patients with colorectal cancer (CRC). Although surgical resection remains the standard of care for these liver metastases, majority of patients have lesions that are unresectable.
Hepatic veno-occlusive disease (VOD) or veno-occlusive disease with immunodeficiency is a potentially life-threatening condition in which some of the small veins in the liver are obstructed. It is a complication of high-dose chemotherapy given before a bone marrow transplant and/or excessive exposure to hepatotoxic pyrrolizidine alkaloids. It is classically marked by weight gain due to fluid retention, increased liver size, and raised levels of bilirubin in the blood. The name sinusoidal obstruction syndrome (SOS) is preferred if hepatic veno-occlusive disease happens as a result of chemotherapy or bone marrow transplantation.
Portal venous pressure is the blood pressure in the hepatic portal vein, and is normally between 5-10 mmHg. Raised portal venous pressure is termed portal hypertension, and has numerous sequelae such as ascites and hepatic encephalopathy.
Selective internal radiation therapy (SIRT), also known as transarterial radioembolization (TARE), radioembolization or intra-arterial microbrachytherapy is a form of radionuclide therapy used in interventional radiology to treat cancer. It is generally for selected patients with surgically unresectable cancers, especially hepatocellular carcinoma or metastasis to the liver. The treatment involves injecting tiny microspheres of radioactive material into the arteries that supply the tumor, where the spheres lodge in the small vessels of the tumor. Because this treatment combines radiotherapy with embolization, it is also called radioembolization. The chemotherapeutic analogue is called chemoembolization, of which transcatheter arterial chemoembolization (TACE) is the usual form.
In oncology, metastasectomy is the surgical removal of metastases, which are secondary cancerous growths that have spread from cancer originating in another organ in the body.
Taurolidine is an antimicrobial that is used to prevent infections in catheters. Side effects and the induction of bacterial resistance is uncommon. It is also being studied as a treatment for cancer.
Subcutaneous T-cell lymphoma is a cutaneous condition that most commonly presents in young adults, and is characterized by subcutaneous nodules. Common symptoms include fever, fatigue, and pancytopenia.
VAMP regimen or VAMP chemotherapy is a four-drug combination chemotherapy regimen, used today in the treatment of Hodgkin lymphoma. It was one of the earliest combination chemotherapy regimens, originally developed as a treatment for childhood leukemia by a group of researchers at the National Cancer Institute led by Emil Frei and Emil Freireich. The first clinical trial of VAMP began in 1961. Because it was the first time that four chemotherapeutic agents were used at once, the trial was highly controversial at its time. Although new combination chemotherapy regimens have replaced the use of VAMP in the treatment of childhood leukemia, VAMP is considered an important precursor to modern treatments, confirming the effectiveness of combination chemotherapy and leading to the use of combination chemotherapy regimens to treat other types of cancer.
Hepatic artery embolization, also known as trans-arterial embolization (TAE), is one of the several therapeutic methods to treat primary liver tumors or metastases to the liver. The embolization therapy can reduce the size of the tumor, and decrease the tumor's impact such its hormone production, effectively decreasing symptoms. The treatment was initially developed in the early 1970s. The several types of hepatic artery treatments are based on the observation that tumor cells get nearly all their nutrients from the hepatic artery, while the normal cells of the liver get about 70-80 percent of their nutrients and 50% their oxygen supply from the portal vein, and thus can survive with the hepatic artery effectively blocked. In practice, hepatic artery embolization occludes the blood flow to the tumors, achieving significant tumor shrinkage in over 80% of people. Shrinkage rates vary.
Interventional oncology is a subspecialty field of interventional radiology that deals with the diagnosis and treatment of cancer and cancer-related problems using targeted minimally invasive procedures performed under image guidance. Interventional oncology has developed to a separate pillar of modern oncology and it employs X-ray, ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) to help guide miniaturized instruments to allow targeted and precise treatment of solid tumours located in various organs of the human body, including but not limited to the liver, kidneys, lungs, and bones. Interventional oncology treatments are routinely carried out by interventional radiologists in appropriate settings and facilities.
Transarterial bland embolization is a catheter-based tumor treatment of the liver. In this procedure, embolizing agents can be delivered through the tumor's feeding artery in order to completely occlude the tumor's blood supply. The anti-tumor effects are solely based on tumor ischemia and infarction of tumor tissue, as no chemotherapeutic agents are administered. The rationale for the use of bland embolization for hepatocellular carcinoma (HCC) and/or other hyper-vascular tumors is based on the fact that a normal liver receives a dual blood supply from the hepatic artery (25%) and the portal vein (75%). As the tumor grows, it becomes increasingly dependent on the hepatic artery for blood supply. Once a tumor nodule reaches a diameter of 2 cm or more, most of the blood supply is derived from the hepatic artery. Therefore, bland embolization and transarterial chemoembolization (TACE) consist of the selective angiographic occlusion of the tumor arterial blood supply with a variety of embolizing agents, with or without the precedence of local chemotherapy infusion. The occlusion by embolic particles results in tumor hypoxia and necrosis, without affecting the normal hepatic parenchyma.
High-dose chemotherapy (HDC) is a regimen of chemotherapy medicines given at larger dosages. This therapeutic strategy is used to treat some cancers, especially those that are aggressive or have a high chance of coming back. With increased doses of chemotherapy chemicals administered to the body, HDC seeks to optimize the death of cancer cells.