Cancer arises when abnormal cells multiply unusually rapidly and accumulate in masses called tumors. Cancer cells are often invasive: they can overrun and destroy normal body tissues, and they can metastasize—spread from their original site to other parts of the body. Doctors have traditionally treated cancer with surgery, radiation therapy, or chemotherapy to try to stop a tumor’s uncontrolled growth.
In interventional radiology, an increasingly important form of cancer therapy, specially trained physicians introduce instruments such as needles or catheters (long, thin tubes) equipped with micro-tools into the body through tiny incisions in the skin. Using imaging techniques such as X-ray, ultrasound, CT, or MRI, they guide the instruments to organ systems throughout the body, and can deliver cancer treatment directly to the tumor. Compared to open surgery, this minimally invasive form of therapy requires less anesthesia, causes less trauma and pain, and patients have shorter hospital stays and recover more quickly.
What is Ablation?
Ablation is an image-guided, non-surgical, minimally invasive treatment in which interventional radiologists guide a needle-tipped catheter directly into a tumor, then shrink or destroy the tumor with extreme heat or cold. Because we use imaging guidance such as CT and ultrasound to precisely locate the tumor, the normal surrounding tissue is spared the effects of the heat or cold. Ablation is currently a standard treatment for inoperable liver tumors, and it is being increasingly used for other cancers, such as lung cancers, kidney (renal), and certain benign and malignant bone tumors, and is being tested for other types of cancer.
We use three different kinds of ablation to treat cancer:
- Radio-frequency ablation, in which we transmit high-frequency electrical currents through the needle, which create enough heat to destroy the tumor cells.
- Cryoablation, a technique in which we circulate argon and helium gas through the needle, lowering the temperature in the tumor to -40°C for several minutes.
- Microwave ablation, in which we transmit electromagnetic microwaves through the needle; these agitate water molecules in the tumor cells, creating enough heat to destroy the tumor cells.
In all forms of ablation, the dead tumor tissue shrinks, slowly “scaring down,” over time, and may eventually disappear. Because ablation can shrink tumors, it may increase longevity, relieve pain, and in some cases can cure cancer.
How do I get ready for the procedure?
Because you will be sedated during the procedure, you should not to eat or drink anything after midnight on the night beforehand, but you may drink water up to two hours before the procedure. We will give you more specific instructions about which medications you may take in the morning. If you are going to be staying in the hospital overnight, bring what you will need for your stay to the appointment.
What will happen during the procedure?
We perform most ablation procedures in an interventional radiology suite on an outpatient basis. After you arrive for your appointment and are ready for the procedure we will position you on the examining table. A nurse or technologist will insert an intravenous (IV) line into a vein in your hand or arm for the sedation medication.
Using an imaging test such as computed tomography (CT), we will locate the tumor, choose an insertion point above a blood vessel for the catheter, then numb the area with a local anesthetic and make a very small incision at the site.
Then, under real-time guidance using ultrasound, or by 3D calculations from the CT images, a probe that transmits heat or cold to the site of the tumor is guided into position.You may need to lie still or hold your breath as the probe is placed into the tumor. Once the probe is in place we will heat or freeze the cancer cells surrounding the probe. If the tumor is large, it may be necessary to reposition the needle into different parts of it to do multiple ablations and ensure that no tumor tissue is left behind.
Each ablation takes about 10 to 30 minutes, but the procedure may take longer if more than one ablation is needed. The entire procedure will take one to three hours. When the treatment is complete, we will remove the probe and place a small bandage over the site of the insertion. You will remain in the recovery room until you are completely awake and ready to return home.
Are there any risks?
In general, ablation is safe.
After the procedure
For the first two to three hours after the procedure, you will be on bed rest while we monitor your vital signs. In some cases patients stay in the hospital overnight. For 24 hours following the procedure, avoid driving a car and exercising strenuously. You should be able to resume your usual activities within a few days. We will ask you to return for follow-up imaging tests, and if the tumor has not shrunk, you may need additional treatment.