What is tumor ablation?
Interventional Radiologists have developed techniques to apply heating or freezing probes directly into tumors to kill cancer cells resulting in the elimination of the need for a bigger surgical procedure. This type of treatment, called tumor ablation, is a relatively new technique that is showing promising results for treating cancer.
Depending on the type of energy used to destroy the tumor cells, it can also be called radiofrequency ablation (heat), microwave ablation (heat), or cryoablation (freeze). Percutaneous ablation techniques can be combined with other therapies (such as CyberKnife) when needed, to best treat a patient’s cancer.
Although most of the time, the goal is to try to destroy all the tumor cells in a given lesion (tumor growth), ablation techniques can also be used to reduce the size of the tumor so that it can be more easily eliminated by chemotherapy or radiation.
What cancers can be treated with image-guided ablation?
Patients with tumors of the liver (primary and metastatic), and other cancers (kidney, adrenal, and lung), as well as bone lesions, may benefit from ablation therapy. Ablation effectively works to shrink small to medium-sized tumors. Emerging technologies hold promise for the treatment of larger cancers in the future.
Although surgery is still considered the standard of care for most tumor growths, percutaneous ablation is an excellent alternative for patients who are not candidates for surgery because their tumors are difficult to reach or are too large or numerous to be removed safely. These techniques are also used in patients with additional medical conditions that make surgery too risky or have tumors that have not responded to previous cancer treatments.
Why is it done?
The main goal of ablation is to basically destroy localized tumors with the intention of cure. In patients with advanced disease, these treatments can help alleviate the pain and other debilitating symptoms caused by tumors. While tumors themselves often are not painful, they may press against nerves or interfere with vital organs, which in turn, can cause pain.
The advantages over surgical resection include faster recovery time and sparing of normal healthy tissue. The latter becomes particularly important in patients with pre-existing problems. For example, if the patient has poor kidney function, removal of one kidney or even part of the kidney may result in liver failure. The ablation techniques are fairly focused and have minimal impact on the normal tissue around the tumor.
What are the risks of percutaneous ablation?
Available since the late 1990s, ablation has been shown to be a relatively safe procedure. As with any procedure, there is a small risk of bleeding. However, depending on where the tumor is located, this risk can be higher. Another potential risk is the seeding or spreading of the tumor. Fortunately, this is also extremely rare (<0.1%). Infections are also a risk but rare after percutaneous ablation.
Overall, the biggest disadvantage of the ablation techniques when compared to surgical removal of the tumors is that there is a higher chance of recurrence. Therefore, after these procedures, it is extremely important to have frequent follow up with imaging studies. If there is a focal site of recurrence within the treated area, these procedures can be repeated as many times as necessary.
Depending on the location of the tumor to be ablated, there are specific risks:
Lung: An organ full of air, the most common complication associated with lung tumor ablation is a lung collapse (pneumothorax). This happens when air escapes from the lung filling the space between the lung and the chest wall, causing part of the lung to collapse. It happens overall in approximately 10% of lung tumor ablations. Fortunately, it is easily treated by placing a small plastic tube in this space to remove the air. This plastic tube will need to stay in place for 24-48 hours until the air leak stops. Usually, the patient will stay in the hospital if this happens for 1-2 days
Liver: Treatment in the liver may cause inflammation of the gallbladder, damage to the bile ducts, or to the bowel.
Kidney: Treatment in the kidney can damage the urine collecting system or cause heavy bleeding.
Some patients may experience “post-ablation syndrome” which are flu-like symptoms that appear 3-5 days after the procedure and usually last about 5-10 days. These symptoms are transient and can be managed with medications.
Reasons to avoid this procedure?
Ablation techniques are usually not effective for tumors >5cm. We believe that patients who are good surgical candidates should consider surgical resection first.
How do you prepare?
Usually, this procedure is performed with IV sedation and local anesthesia. You will need to be fasting for 8 hours before the procedure. We recommend no eating or drinking after midnight before the procedure. Generally, you should take your daily morning medications with a small sip of water.
If you take blood thinners you need to stop before the procedure. Please refer to pre-procedure instructions for detailed instructions about your medications.
Please leave all valuables such as jewelry, credit cards, and money at home on the day of the procedure. Family members may wish to bring a magazine or book to read during the extended wait time.
After checking in at Patient Registration, you will be directed to the Short Stay pre-procedure unit on 2B. Once in the department, a nurse will prepare you for the procedure. This preparation will include changing into a gown, a nurse taking your vital signs, starting an IV in your arm, lab tests, and giving you IV fluids and IV medications (antibiotics, anti-nausea, etc).
Once you are prepared for the procedure another nurse or someone from the anesthesia department will come and get you and take you to the procedure room. A radiology technologist, a radiology nurse, and an interventional radiologist will be waiting for you and will remain with you for the length of the procedure.
How is the procedure done?
The procedure is performed at El Camino Hospital in the radiology department. An entire team will be taking care of you during the procedure including a radiology nurse, a radiography technologist, and the physician. In the procedure room, the nurse will help you lay on an exam table. You will be connected to heart rate, oxygen saturation, and blood pressure monitors. IV medicine will be given to sedate you. Your procedure area will be shaved and washed with a special soap and covered with sterile sheets. Local anesthetic medicine is injected into the area. You will feel some burning as the medicine is given. Once it takes effect, the area will be numb.
Pictures will be taken with the CT and ultrasound (US) machine to locate the tumor being treated. Once we locate the tumor, a needle probe will be inserted through your skin into the tumor under direct imaging guidance. Once the probe is in the correct location, it will be attached to an energy source that delivers heat (using radiofrequency or microwave energy) or freezing (cryoablation). Although the ablation time varies, it is usually around 10 minutes. The interventional radiologist will monitor the area being treated on the CT or ultrasound machine. Several tumors can be treated in one session or the procedure can be repeated as often as needed to treat new tumors as they arise.
The procedure time varies but usually takes 1 to 2 hours. Throughout the procedure, medication is given through your IV to keep you comfortable. Your oxygen saturation, blood pressure, and pulse are checked closely during and after the procedure.
What you can expect after the procedure?
Once your procedure is over you will go to the post-anesthesia recovery unit for approximately 1 hour. You will be able to eat and drink as soon as you are awake. A nurse will monitor your heart rate, oxygen saturation, blood pressure, and the site where your procedure was performed. Let the nurse know if you are experiencing any pain or discomfort at this time. After approximately 1 hour you will transfer to a regular post-op room where you can see your family members. Some patients may feel well enough to go home that day, while others may be admitted to stay overnight for observation and pain management.
How long does it take to recover?
The ablation treatments are in general very well tolerated. Most patients experience short recovery times and can resume their usual activities a few days after completing treatment
What should you watch for?
You may be sore after the procedure. However, the pain should not be getting worse and should subside in 2-3 days. If you develop severe pain or if the pain is getting worse you should call us and seek immediate medical attention.
Fever (>101F), worsening of pain, redness, swelling, warmth, or discharge at the site of the procedure may be signs of infection.
What follow up is necessary?
Usually, you should see the interventional radiologist approximately 1 week after the procedure to assure the site is healing well. An imaging study is necessary approximately 6 weeks after the procedure to be certain the treatment has been effective. CT or MRI is the imaging method of choice. At that time you will also meet with the interventional radiologist to evaluate the images.