Cryotherapy

What is Cryotherapy

Cryotherapy, also called cryosurgery, cryoablation or targeted cryoablation therapy, is a minimally invasive treatment that uses extreme cold to freeze and destroy diseased tissue, including cancer cells.

In cryotherapy, liquid nitrogen or argon gas is applied to diseased cells located outside or inside the body. Physicians use image-guidance techniques such as ultrasound, computed tomography (CT) or magnetic resonance (MR) to help guide these freezing substances to treatment sites located inside the body.

What are some common uses of the procedure?

Cryotherapy is used to treat:

• skin tumors
• pre-cancerous skin moles
• nodules
• skin tags
• unsightly freckles
• retinoblastomas, a childhood cancer of the retina
• prostate, liver and cervical cancer, especially if surgery is not possible.

Research is currently being done to determine the effectiveness of cryotherapy for tumors of the bone, brain, kidney, lung and spine. Researchers are also also evaluating its usefulness in freezing and shrinking benign breast lumps, called fibroadenomas.

How should I prepare?

Some physicians recommend taking ibuprofen (400 mg) a half-hour before this procedure to relieve minor discomfort; others give a dose of antibiotics before cryotherapy as a way to guard against infection.

You should report to your doctor all medications that you are taking, including herbal supplements, and if you have any allergies, especially to anesthesia or to contrast materials (also known as "dye" or "x-ray dye"). Your physician may advise you to stop taking aspirin or a blood thinner for a specified period of time days before your procedure.

Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy because radiation can be harmful to the fetus. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays.

If you are having intraoperative cryotherapy to treat tissue within your body, you should plan to stay overnight at the hospital following your procedure.

You should plan to have a relative or friend drive you home after your procedure.

You may be asked to wear a gown during the procedure.

What does the equipment look like?

In this procedure, ultrasound, computed tomography (CT) or magnetic resonance (MR) imaging, a cotton swab or spray device, cyroprobe and bronchoscope may be used.

Ultrasound scanners consist of a console containing a computer and electronics, a video display screen and a transducer that is used to scan the body and veins. The transducer is a small hand-held device that resembles a microphone, attached to the scanner by a cord. The transducer sends out high frequency sound waves and then listens for the returning echo. The principles are similar to sonar used by boats and submarines.

The ultrasound image is immediately visible on a nearby screen that looks much like a computer or television monitor. The image is created based on the amplitude (strength), frequency and time it takes for the sound signal to return from the patient to the transducer.

The CT scanner is typically a large machine with a hole, or tunnel, in the center. You will lie on a table which slides into and out of this tunnel. The x-ray tube and electronic x-ray detectors rotate around you. They are opposite each other in a ring, called a gantry. The computer workstation that processes the imaging information is located in a separate room.

The traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table that slides into the center of the magnet.

Some MRI units, called short-bore systems, are designed so that the magnet does not completely surround you; others are open on all sides (open MRI). These units are especially helpful for examining patients who are fearful of being in a closed space and for those who are very obese. Newer open MRI units provide very high quality images for most types of exams; however, open MRI units with older magnets may not provide this same quality. Certain types of exams cannot be performed using open MRI. For more information, consult your doctor.

The computer workstation that processes the imaging information is located in a separate room.

Cryotherapy to treat tissue located outside the body uses a cotton swab or spray device.

Cryotherapy to treat tissue located inside the body requires image guidance and a cryoprobe, a thin wand-like device with a handle or trigger or a series of small needles. The cryoprobe is connected via tubing to a source of nitrogen or argon. Most cryotherapy units use argon gas and are approved by the U.S. Food and Drug Administration (FDA) for general urologic and oncologic uses.

A bronchoscope, a thin, lighted tube used to examine the inside of the trachea and bronchi, or the air passages that lead into the lungs, may also be used.

Other equipment that may be used during the procedure includes an intravenous line (IV) and equipment that monitors your heart beat and blood pressure.

How does the procedure work?

Cryotherapy applies nitrogen or argon gas at extremely cold temperatures to destroy diseased tissue. To destroy diseased tissue located outside the body, liquid nitrogen is applied directly with a cotton swab or spray device. For internal tumors, the physician will use image-guidance to insert a cryoprobe or a series of small needles through the skin to the site of the diseased tissue and then deliver liquid nitrogen or argon gas.

Living tissue, healthy or diseased, cannot withstand extremely cold conditions and will die from:

• ice within the cell. At approximately -40°C (-40°F) or less, intracellular lethal-ice crystals begin to form that will tear apart almost any cell.
• bursting from swelling or shrinking. If ice forms only outside the cell, osmosis—the movement of a solution through the membrane of a cell—causes the cell to shrink as it gives up water to replace the water that has turned to ice. Then, as the area thaws, water rushes into the shrunken cell and causes it to burst. For this reason, cryotherapy usually consists of a series of steps in which tumors are repeatedly frozen and thawed.
• loss of blood supply. Cells die when their blood supply is choked off by ice forming within small tumor vessels, causing clotting. Since the average blood-clotting time is approximately 10 minutes, the extreme cold is maintained for at least 10 minutes unless tumor temperatures indicate that lethal-ice temperatures have been reached.

Once the cells are destroyed, the white blood cells of the immune system work to clear out the dead tissue. There is some evidence to suggest that this procedure also stimulates the immune system to attack remaining cancer cells.

How is it performed?

Image-guided procedures such as cryotherapy are most often performed by a specially trained interventional radiologist in an interventional radiology suite or occasionally in the operating room.

This procedure is often done on an outpatient basis.

You will be positioned on the examining table.

To destroy diseased tissue located outside the body, your physician will apply liquid nitrogen to the area with a cotton swab or spray device.

For internal tumors, your physician will perform a percutaneous procedure, which involves inserting small, hollow, needles through the skin.

You will be connected to monitors that track your heart rate, blood pressure and pulse during the procedure.

A nurse or technologist will insert an intravenous (IV) line into a vein in your hand or arm so that sedative medication can be given intravenously. You may also receive general anesthesia.

The area where the electrodes or cryoprobe are to be inserted will be shaved, sterilized and covered with a surgical drape.

A very small nick is made in the skin at the site.

Using image-guidance, the physician will insert the cryoprobe or a series of small needles through the skin to the site of the diseased tissue. Once the needles or cryoprobe(s) are in place, the liquid nitrogen or argon gas is delivered.

For prostate cancer, six to eight needle probes are inserted through the perineum (the tissue between the rectum and the scrotum and penis) using ultrasound guidance.

At the end of the procedure, the needles or cryoprobe(s) are removed and pressure will be applied to stop any bleeding. The opening in the skin is covered with a bandage. No sutures are needed.

Your intravenous line will be removed.

The entire procedure is usually completed within one to two hours.

What will I experience during and after the procedure?

Devices to monitor your heart rate and blood pressure will be attached to your body.

You will feel a slight pin prick when the needle is inserted into your vein for the intravenous line (IV) and when the local anesthetic is injected.

If you receive a general anesthetic, you will be unconscious for the entire procedure, and you will be monitored by an anesthesiologist.

The intravenous (IV) sedative will make you feel relaxed and sleepy. You may or may not remain awake, depending on how deeply you are sedated.

You may experience discomfort from having to be still during the procedure.

Following percutaneous cryotherapy, you should be able to resume your usual activities within 24 hours.

If you have had intraoperative cryotherapy, you should be able to resume your usual activities within seven to 10 days. You should avoid lifting heavy objects for at least 72 hours.

Who interprets the results and how do I get them?

The interventional radiologist or physician treating you will determine the results of the procedure and will send a report to your referring physician, who will share the results with you.

What are the benefits vs. risks?

Benefits

• For intraoperative cryotherapy of kidney or liver tumors, recovery time is usually much less than for major surgical removal of the tumor. Patients are usually discharged from the hospital in less than half the time needed to recover from major surgery.
• For percutaneous cryotherapy, the patient may stay overnight or be released several hours after the procedure. Unlike heat-based treatments such as radiofrequency, cryotherapy causes minimal pain after the procedure and overnight stays for pain control are usually not needed. Therefore, cryotherapy has great potential to evolve into an outpatient procedure.
• Percutaneous cryotherapy is less traumatic than open surgery since only a small incision is needed to pass the probe through the skin, which limits damage to healthy tissue. Consequently, percutaneous cryotherapy is less costly and results in fewer side effects than open surgery. A patient usually can resume activities of daily living 24 hours after the procedure, if not sooner. However, caution about heavy lifting may extend for several days after abdominal treatment.
• For treatment of fibroadenomas, cryotherapy causes minimal scar tissue and no apparent calcifications. Consequently, screening mammography can continue to be carried out without the potential for calcifications being misidentified as breast disease.

Risks

• Treatment of the liver can damage bile ducts or cause heavy bleeding. If the freeze is near the diaphragm, fluid can accumulate in the space around the lungs.
• Treatment of the kidney can damage the urine-collecting systems or cause heavy bleeding.
• Any treatment of the abdomen needs to be carried out carefully around the bowel since damage may cause a hole in the bowel, which may release bowel contents into the abdomen and can lead to infection.
• Treatment of lung tumors can cause the lung to collapse and fluid to accumulate around the lung.
• Care must be taken anywhere nerves are near the tumor. Completely frozen nerves can cause motor weakness or numbness in the area supplied by the nerves.

Cryotherapy may be more complicated for prostate cancer and:

• Usually requires a short hospital stay.
• May cause permanent impotence since nerves controlling sexual potency are commonly involved in the freezing process. However, nerves can regenerate, resolving the problem in some patients.
• While the patient is under anesthesia, a bladder tube is positioned to drain urine until the swelling of the bladder neck—as a result of the procedure—resolves.
• May cause urethral sloughing; that is, blocking of the urine stream with dead tissue. Sloughing is reduced by keeping the urethra warm with sterile water circulating continuously through a catheter placed in the urethra during the procedure.

What are the limitations of Cryotherapy?

Cryotherapy is an alternative cancer treatment when surgical removal of a tumor may be difficult or, for some patients, impossible. But its long-term effectiveness is still being examined. Currently, little published data deal with the results of percutaneous cryotherapy but seven-year follow-up for prostate cancer suggests cancer-control rates are similar to surgery or radiation therapy.

Cryotherapy is considered a localized therapy. It can only treat disease at a single site. It cannot treat cancer that has spread to other parts of the body. Because physicians treat the tumors they see on radiologic images, microscopic cancer may be missed.

Although its use in the bone, kidneys, liver and lung is promising, cryotherapy may be considered experimental; consequently, many medical insurance companies will not pay for the procedure. Although there is general U.S. Food and Drug Administration (FDA) approval, the experience with cryotherapy is still early and most physicians reserve it for patients who are not good candidates for other cancer treatments.