Radiofrequency ablation is a medical procedure used in cancer treatment to eliminate tumors and metastases. It is also used for arthritis pain. The pain relief in these cases can last anywhere from 6 months to a year. The percentage of people actually experiencing pain relief is estimated at over 70%. Sometimes, the pain relief lasts for years.
Medical doctors have been using radiofrequency ablation for cancer for the past 28 years. Amongst the list of other conditions that it’s been used for are prostate enlargement, heart arrhythmias, and a type of benign bone tumor called osteoid osteoma.
Who can’t have radiofrequency ablation
The only people that should not have radiofrequency cancer treatment are:
- Those who have bleeding disorders
- Those currently suffering from infections
- Those who will need deep sedation (for the percutaneous approach)
- Those whose tumors do not have a normal margin of cells (it’s 100% cancer cells)
How RFA Ablation is performed
The procedure for ablation therapy is pretty straightforward:
- Your body is prepared for an IV line to go into a vein close to the area of the problem.
- A type of anesthetic or sedative is administered and the doctor will watch you to make sure the anesthetic is activated in your body.
- A 1-2 mm wide 18-gauge to 14-gauge needle (probe) will be inserted into the area of treatment with the aid of x-ray. If the tumor is large, multiple probes will be used. One needle takes care of about 1.6 centimeters of cancerous tissue. However, with advanced technology, this distance can now be extended up to 7 centimeters, which is 2.75 inches.
A treatment lasting 30 minutes has very few complications and cells other than the cancer cells do not die. The x-ray helps your doctor locate the target area to treat it. Once found, an electrode is inserted to stimulate the cells in the area with radio waves.
The purpose of this stimulation is to allow the doctor to verify that the placement is exactly correct. Advanced methods of using the technique include slow or pulsed heating, using multiple probes, internal electrode cooling and infusing saline into the area.
- Next, an RF (radiofrequency) current is dispelled into the area. The stimulation may last anywhere from 30 minutes to 120 minutes. The tissue heats up and then cells susceptible to the heat die. The cells heat up to 50-52 degrees Celsius (122 degrees Fahrenheit to 125.6 degrees Fahrenheit), and after 4 to 6 minutes, the targeted cancer cells begin to die.
It is more difficult to use the ablation procedure for a tumor that lies next to arteries or veins larger than 3 mm in diameter. That’s because the transfer of heat could affect the blood vessels negatively. For this reason, the doctors may have to clamp off the blood vessels, cause a temporary clot (called an occlusion balloon) in the blood vessels for a few minutes, or create an embolism with chemicals in the blood vessels.
After the procedure, anywhere from two to six weeks later, new imaging studies such as MRI are taken. They are repeated every 90 days for up to a year or longer. Doctors will want to repeat the ablation if the tumor starts growing again. The fear on the part of the doctors is that any new growth will be pretty erratic in its geometry, which would make further treatment quite difficult.
What type of precautions should the patient take?
The procedure doesn’t restrict what you eat or drink but it is not a good idea to do any of the following after the ablation therapy:
- Driving, especially farm equipment
- Exercising strenuously at the gym or elsewhere
How effective is radiofrequency ablation for cancer when guided by imagery?
It doesn’t have to be a blind procedure. It can be guided by imagery. This isn’t referring to the psychological technique where someone imagines the body’s immune system cells attacking the cancer cells to kill them. Instead, it means that the doctor has cameras inside your body so he can see exactly where he is in the tissue, to avoid damaging tissues that are healthy and go right after the cancer cells alone.
The Mayo Clinic has the answer to whether or not radiofrequency ablation for cancer is effective when guided by medical imagery systems. The doctors at this prestigious institution recently published a medical study on the results in July 2017 in the Journal of Vascular Intervention & Radiology. This powerful study tracked 16 patients with prostate cancer who were between the ages of 50 and 86 years old and had cancer that had metastasized (spread) to other areas of the body.
The doctors found that 27 months after the patients received radiofrequency ablation with the assistance of imagery to see what parts of the body were being ablated, 15 of 18 of the tumor metastases were controlled. The tumor recurrence rate only occurred in 16.6% of the tumors. That’s a very low rate, compared to some other procedures.
In this study, tumors did not recur until 3.5 months later on average so the patients had about 105 days where they were declared tumor-free. The local ablation worked. (Local ablation means only the tumor that is in one location is addressed.)
The doctors concluded that the radiofrequency ablation was feasible and well-tolerated and achieved acceptable local tumor control rates and the method may be useful to patients with prostate cancer who aren’t ready or want to delay androgen-deprivation therapy (ADT).
Freezing cancer tumors works
The type of ablation treatment done at the Mayo Clinic in this study is called Percutaneous Imaging-Guided Cryoablation or PICA. It’s one that closely views tumors as they are being destroyed with extremely cold temperatures, instead of heat from radio waves. Doctors and patients both like using it because it’s minimally invasive, safe, repeatable, and can be used with other cancer therapies.
When Cryotherapy and Radiofrequency Ablation for Cancer are used together, according to researchers in France and Italy, PICA has been used in a wide range of patients and tumors with great success.
For example, the following conditions have resulted in reports of curative therapy:
Small primary/secondary lung tumors
In India, doctors reviewed 14 cases where RFA ablation was used for lung metastasis between January 2007 and December 2013. The size of the metastases ranged from 0.5 to 5.0 centimeters. The primary cancers associated with these metastases were liver cancer, colorectal cancer, and prostate gland cancer. The average patient age was 50 years old.
The medical reports showed complete ablations without local tumor recurrence in 81% of the nodules. The Indian doctors concluded that radiofrequency ablation for lung metastasis can be considered as a relatively safe, effective alternative treatment for lung metastasis.
Bone growths and the relief of pain of bone metastases
Radiofrequency cancer treatment can be performed on both benign bone growths and ones that are cancerous. In bone, the procedure varies a little. The probe is placed in a bone-penetration cannula into the tumor and then activated at 90 degrees Fahrenheit for 4-6 minutes. Success rates for doing the procedure only once are as high as 91-94%. Most recurrences can be ablated when the procedure is repeated.
When cancer metastasizes to the bone, the patient suffers from a lot of pain. One study of 43 patients with a bone metastasis that was very painful and resistant to chemotherapy and radiation proved pain relief was possible. The patients had so much pain relief that they used significantly less analgesics to control pain.
Small T1a kidney tumor
Kidney tumors that are in the interior of the kidney are a potential problem because of the blood vessels that run through this area. The tumors treated should also be less than 3 centimeters in diameter.
RFA ablation therapy may be a good choice of technique to use for small renal masses, according to the National Institutes of Health and the National Cancer Institute. It’s especially good for patients with a genetic predisposition to have multiple metachronous kidney cancers, such as what happens in von-Hippel Lindau, or hereditary papillary renal cancer. So far, results of studies in this area of renal tumors and radiofrequency ablation have shown a 70-90% success rate for the first ablation procedure. When the second procedure is done, the success rates will be higher.
The tumor type which responds best to RFA is an exophytic tumor of the kidney. This is a tumor that grows outside the surface of the epithelial cells from where it starts. In other words, it’s similar to how a mushroom grows, and how a mushroom can be plucked off the area from where it originates. Complications are rare when ablation is used in the kidneys.
Doctors at Memorial Sloan Kettering Cancer Center in New York reviewed 110 patients that received ablation of colorectal liver metastases between November 2009 and April 2015. Six weeks after the procedure, the margins of the metastases were measured.
The doctors compared different types of radiofrequency ablation, thermal ablation (microwave ablation procedure), and ablation of colorectal liver metastases. They found that the technique of complete ablation was 93% successful and 97% successful for the microwave version of it. The tumors were completely gone in these cases.
The doctors determined that predictors of success included metastases that had 5 mm margins or less, and perivascular tumors. A perivascular tumor is a rare type of tumor that can occur anywhere in the body. Where this tumor originates is not known at this time. Most commonly, they are found in the lungs or in the kidneys.
In the study, even the largest tumors (over 10mm) did not metastasize when the RFA ablation was done. They concluded that regardless of the thermal ablation modality used, margins greater than 5 mm are critical for local tumor control, with no local tumor progression noted for margins over 10 mm. Unlike RF ablation, the efficiency of microwave ablation procedure was not affected for perivascular tumors.
If patients have liver cirrhosis along with a liver tumor, they aren’t a candidate for radiofrequency ablation.
Ablation therapy is not universally available
Not all doctors will use radiofrequency ablation procedure (local ablation or cryoablation). In one national doctor survey, only 16% of doctors had access to local tumor ablation methods at their place of work. These doctors were primarily ones that were associated with universities.
Yet not all doctors at universities used ablation therapy because of a lack of radiologists that could assist with and/or perform the procedure, and lack of expertise with the procedure. The doctors that do use ablation therapy use local tumor ablation, percutaneous radiofrequency and cryoablation. We use it here at Williams Cancer Institute because it works well as seen in our hundreds of patient cases.
If you or a loved one have any more questions or need information about radiofrequency ablation, OX40 cancer immunotherapy, or cd40 cancer immunotherapy, give us a call at Williams Cancer Institute.
Erie, A.J., et al. Retrospective review of percutaneous image-guided ablation of oligometastatic prostate cancer: a single-institution experiment. J Vasc Interv Radiol 2017 Jul; 28(7):987-92. https://www.ncbi.nlm.nih.gov/pubmed/28434661
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