New Cancer Treatments on the Horizon

Interventional radiology is playing a role in developing new techniques that may improve cancer treatment in the future, including the use of magnetic particles to draw cancer-killing agents into tumors; and the delivery of genetic material, called gene therapy, to fight or prevent cancers. These techniques are still investigational, but they offer new hope in the war against cancer.

"Magnetic"Chemotherapy

Interventional radiologists are currently investigating a new technique in which magnets are used to pull chemotherapy drugs into tumors. Microscopic magnetic particles are attached to the cancer-killing drugs and infused through a catheter into the blood vessel that feeds the tumor. A rare earth magnet is positioned over the patient’s body directly above the site of the tumor. The magnet pulls the drug-carrying particles out of the blood vessel so that they lodge in the tumor. Although the technique is still experimental, early research is promising. Physicians are hopeful that it will bolster the effects of chemotherapy while avoiding some of the drugs’ side effects, such as hair loss and nausea.

Gene Therapy

In recent years, scientists have gained a new understanding about genes—the basic biological units of heredity—and the role they play in disease. This knowledge has set the stage for medical science to alter patients’ genetic material to fight or prevent cancer. Although the science of gene therapy is still in the early, experimental stages, researchers are hoping that in the future the therapy can be used to:

  • alter the cells of a patient’s natural immune system with cancer-fighting genes and returning them to the body, where they could more forcefully attack the cancer;
  • remove cancer cells from the body and alter them genetically so that the patient’s own immune system will mount a strong defense against them. In this technique, the altered cancer cells would act as a cancer vaccine;
  • replace a faulty gene responsible for the growth of cancer with a "good" gene;
  • inject a tumor with genes that will make it more susceptible to chemotherapy or other cancer-fighting agents; and
  • make bone marrow and other organs resistant to chemotherapy, so that the drugs will destroy tumors without damaging healthy tissue.

One of the challenges of gene therapy is finding safe and effective ways to deliver genes or genetically altered cells to the site of the tumor. Interventional radiologists, with their special expertise in using X-rays and other imaging techniques to guide catheters and other tools through the body are expected to play an important role in this new technology.

Treatments for Cancer Complications

There are also a number of interventional radiology techniques that are used to treat the complications of cancer, including pain, bleeding, obstruction of vital organs, blood clots and infection. Although these treatments do not cure cancer, they can make patients more comfortable, extend life by treating serious complications and improve the quality of life for cancer patients.

Treating Pain

Control of pain is one of the most important aspects of cancer care. Pain not only affects patients’ quality of life and ability to function, it may also lower their tolerance for needed cancer treatments.

In many cancer patients, pain results from the spread of the tumor into surrounding nerves and other tissues. For example, patients with cancer of the pancreas or stomach, sometimes experience pain from the spread of the tumor into a network of nerves and blood vessels in the abdomen called the celiac plexus. To treat the pain, interventional radiologists insert catheters or needles into the affected area and administer alcohol or other agents that destroy the nerves causing the pain.

A particularly painful complication of cancer is when the disease spreads (metastasizes) to bones. In a technique called transcatheter embolization, interventional radiologists inject tiny particles, the size of grains of sand, through a catheter and into the artery that supplies blood to the tumor. The particles cause clotting that decreases the tumor’s blood supply, reducing pain and decreasing the likelihood of bone fracture.

Controlling Bleeding

If a cancer spreads to the blood vessels it may cause hemorrhage or bleeding. An interventional radiology technique called transcatheter embolization can be used to clot the affected blood vessels and stop the bleeding.

Treating Organ Obstruction and Infection

Cancers can obstruct the normal flow of urine or bile, causing these fluids to build up in the body. If left untreated, these conditions are not only painful but may also result in organ failure or infection. Under X-ray guidance, catheters can be inserted to drain the collection of fluids. Often, a small device called a stent is inserted into the organ to bypass the obstruction and allow fluids to drain internally.

Treating Blood Clots

One common side effect of cancer or cancer treatments is the development of blood clots, or emboli, that can be life-threatening if they travel to the brain, lungs or heart. There are two interventional radiology procedures that can reduce the risks posed by blood clots:

 Stents
Small mesh cylinders called stents are used to open obstructed organs and allow fluids such as urine and bile to drain.

  • Intra-arterial thrombolysis. In this technique, the interventional radiologist guides a catheter through the blood vessels and to the site of a blood clot.
    Clot-busting drugs are infused through the catheter to break up the clot.
  • Filter placement. This technique is most often used when a blood clot is detected in the blood vessels of the leg (a condition called deep vein thrombosis). The interventional radiologist guides a small filter into the blood vessel that receives blood from the lower body (the vena cava) and carries it to the heart. If the blood clot dislodges from the vein in the leg, the filter will trap it before it can reach the heart.

Interventional Radiologists are Minimally Invasive Experts

Interventional radiologists work with other specialists on a multidisciplinary cancer team to determine the best treatment for each individual patient. Interventional radiology is a recognized medical specialty by the American Board of Medical Specialties. Interventional radiologists are board-certified physicians with extensive training in disease diagnosis, management and treatment. Their board certification includes both Vascular and Interventional Radiology and Diagnostic Radiology which are administered by the American Board of Radiology. This training marries state-of-the-art imaging and diagnostic expertise, coupled with clinical experience across all specialties and in-depth knowledge of the least invasive treatments. Interventional oncology is a growing area within interventional radiology.


 

Reprinted with permission of the Society of Interventional Radiology © 2010
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