Questions and Answers about Minimally Invasive Treatments for Cancer

Q.  What is cancer and how do cancer cells grow?
A.  Normally, cells grow and divide to form new cells as the body needs them.  When cells grow old, they die and new cells take their place.  Sometimes this orderly process goes awry—new cells from when the body does not need them, or old cells do not die when they should.  These extra cells can form a mass of tissue, or tumor.  Cancerous tumors are abnormal and divide without control or order.  To continue growing, a tumor generates its own blood supply to provide oxygen and nutrients.  Cancerous cells can also travel throughout a person’s blood stream and become embedded in other organs, a process known as metastasis.

Q.  Why are interventional radiologists part of the cancer team?
A.  Interventional radiologists are physicians who specialize in minimally invasive, targeted treatments performed using imaging for guidance to treat diseases nonsurgically through the blood vessels or through the skin.  They can attack cancerous tumors without medicating or affecting other parts of the body.
Interventional radiologists can also help diagnose cancer, through a variety of techniques:  A CT scan, MRI or ultrasound can be performed to see inside the body and identify a tumor, or an image guided needle biopsy can be done to remove tissue samples and look for cancer cells.  Needle biopsy is typically an outpatient procedure with very infrequent complications; less than one percent of patients develop bleeding or infection.  In about 90 percent of patients, needle biopsy provides enough tissue for the pathologist to determine the cause of the abnormality.

Q.  How can you treat cancer nonsurgically?
A.  There are two main methods by which interventional radiologist can treat cancer.  The first is to use the vascular system to deliver Chemotherapy medicine directly to the cancer’s blood supply.  This limits damage and toxicity to the rest of the body while delivering the highest possible dose of chemotherapy to the cancer.  This technique is often used in combination with embolization, in which small beads or other embolic agents are injected to the site of the tumor, preventing chemotherapy flow to healthy areas of the body and allowing a higher dose of chemotherapy to be used locally at the site of the tumor.  In some cases, a technique called radioembolization is used.  This is similar to chemoembolization, except that radioactive microspheres are delivered to the tumor, where they exert local radiation and kill cells.
The second method is to “cook” (radiofrequency ablation) or “freeze” (Cryoablation) the cancer by sticking a small, energy-delivering needle directly into the cancer that heats or freezes the cancer without significant damage to nearby normal tissue.  Since these techniques are delivered at the cancer specifically, patients have fewer overall side effects.

Q.  What are thermal ablation techniques?
A.  Ablation means “destruction” or “detachment”.  There are two types of thermal ablation:

• Radiofrequency ablation (RFA).  In this procedure, the interventional radiologist guides a small needle through the skin into the tumor.  Radiofrequency energy (similar to microwaves) is transmitted to the tip of the needle, where it produces heat and kills the tumor near the needle.  The tumor remains as a mass or scar of dead tissue.  RFA is ideal for nonsurgical candidates and those with smaller tumors.
• Cryoablation.  Cryablation is similar to RFA, but rather than killing the tumor with heat, it uses an extremely cold gas to freeze it.  The “ice ball” that is created around the needle grows in size and freezes and destroys the tumor cells.

Q.  What will my recovery be like?
A.  Thermal ablation techniques can be performed without affecting the patient’s overall health and most people can resume their usual activities in a few days.  For most interventional radiology treatments, the recovery period is shorter thant for surgical treatments.

Q.  What are the benefits?
A.  The benefits of interventional radiology techniques include:

• Relief of pain and suffering for many cancer patients
• High tolerability-most patients can resume their normal routines the next day and may feel tired only for a few days
• Usually no requirements for general anesthesia
• Possibility of repeating if necessary
• Possibility of combining with other treatment options
• Relatively low cost
• Generally short hospital stay or outpatient procedure
• Few complications
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Q.  What are the risks?
A.  The risks of ablation are similar to those of a biopsy, namely localized bleeding and some pain.  Bleeding that requires action is uncommon partly because the heat from the radiofrequency energy cauterizes the tissue and minimizes the risk of hemorrhage and the applicators used for both RFA and cryoablation are small in diameter.  Because it is a local treatment that can be controlled and does not require therapeutic doses of radiation, the treatment can be repeated as often as needed.  For interventional radiology techniques generally, the risks are lower and the recovery faster than for surgical procedures.

Q.  What is chemoembolization?
A.  Embolization is a well-established interventional radiology technique that uses small solid particles or special liquid agents to block the flow of blood.  This can be used to treat trauma victims with massive bleeding, to control hemorrhage after childbirth, to decrease blood loss prior to surgery and to treat tumors.  In treating cancer patients, interventional radiologists use embolization to cut off the blood supply to the tumor.  This technique can be combined with delivery of radiation to a tumor (radioembolization), or with chemotherapy to deliver the cancer drug directly to the tumor (chemoembolization).
Chemoembolization delivers a high dose of cancer-killing drug (chemotherapy) directly to the organ while depriving the tumor of its blood supply.  Using imaging for guidance, the interventional radiologist threads a tiny catheter up the femoral artery in the groin into the blood vessel supplying the tumor.  The
embolic agents keep the chemotherapy drug in the tumor by blocking the flow to other areas of the body.  This allows for a higher dose of chemotherapy drug to be used, because less of the drug is able to circulate to the healthy cells in the body.  Chemoembolization usually involves a hospital stay of two to four days.  Patients typically have lower than normal energy levels for about a month afterwards.