The beneficial applications of blasting tumors with needle probes that emit vaporizing heat or freezing cold have blossomed, creating more options for cancer patients here, says Spokane interventional radiologist Ken Symington.


The techniques, called percutaneous radiofrequency ablation and percutaneous cryoablation, respectively, are being performed here at Sacred Heart Medical Center & Childrens Hospital by interventional radiologists, including Symington and several of his colleagues from Spokane-based Inland Imaging LLC.


Symington says both techniques now are proving useful for treatment of cancerous and non-cancerous tumors in the lungs, kidney, liver, and bones, in addition to the more familiar use of cryoablation for treatment of prostate cancer.


Irving, Calif.-based Endocare Inc., which sells equipment for cryoablation, has expanded its focus from prostate cancer to include other types of cancer, and the National Cancer Institute now is supporting a study comparing the use of cryoablation to radiation therapy for treatment of cancer pain in the bones.


In either procedure, the doctor inserts one or several needle probes directly through the skin into a tumor, using a series of real-time computed tomography (CT) images to guide the probe. Magnetic resonance imaging and ultrasound sometimes are used instead of CT scans to view the procedure, Symington says.


Once the probe is positioned with the tip directly in the center of the tumor, the radiologist applies electrical heat in the form of radio waves to vaporize the tumor at 100 degrees Celsius (212 degrees Fahrenheit) or applies cold at -100 degrees Celsius to freeze it, killing the abnormal tissue.


Symington says the epicenter of the heat vaporizes the cells, while surrounding cells that reach a temperature of at least 60 degrees Celsius will die or be unable to divide. Outside of that hot zone cells that reach up to 40 degrees Celsius also might die or be damaged.


If cryoablation is used, the cells that are frozen to at least -40 degrees Celsius will die, Symington says.


The techniques can treat tumors as small as 1 centimeter and as large as 12 centimeters, using one or more probes simultaneously, depending on the size of the tumor, Symington says.


Patients typically are referred for the treatment by an oncologist or sometimes by a pulmonologist, Symington says. The cost of the procedures, which generally take about 45 minutes, is less than the cost of surgery, Symington says. Symington and three of the eight other interventional radiologists at Inland Imaging have subspecialized in cancer treatment and between them perform about 10 of the procedures here each month, he says.


A Sacred Heart representative declines to say how much the equipment costs, but says it doesnt represent a big capital investment. The hospital already owned a radiofrequency generator that sometimes is used in other surgical procedures. The radiofrequency ablation and cryoablation procedures are performed in one of the hospitals regular CT suites. The disposable probes are attached either to the radiofrequency electrical generator, or to tanks of argon gas for use in cryoablation.


The procedures often are done on an outpatient basis, though some patients stay in the hospital overnight depending on bleeding or side effects from anesthesia. Patients can recover from ablation procedures in a couple of days, Symington says.


After an ablation, a patient returns for follow-up CT images in one month, six months, and a year. Symington says both of the procedures also can be used in conjunction with other treatments.


The two procedures rapidly are entering mainstream use as more doctors recognize them as additional, less-invasive options for the treatment of tumors, Symington says.


He asserts that ablation has the potential to reduce or cure a host of different cancers with faster healing and fewer side effects than common cancer treatments such as surgery, chemotherapy, and radiation therapy.


One of the advantages of both types of ablation, Symington says, is that they can be used more than once.


You dont burn any bridges, he says.


Though less invasive than surgery, there are certain risks associated with the procedures, including pain at the site, infection, and bleeding, he says. Also, depending on where a treatment is administered, risks could include perforation of the bowel or scarring of surrounding tissue, he says. Symington says interventional radiologists consider how close tumors are to other organs that could be damaged when evaluating patients for the procedures.


Each type of ablation has advantages, he says. For example, with radiofrequency ablation, the probe can act as a cauterizing mechanism as it is removed from the patient, reducing the amount of bleeding experienced after the procedure, while the cold temperatures during cryoablation serve as a natural pain anesthetic.


The cold formed around the tip of the needle probe during cryoablation has a sharper edge that can often be seen better on the CT scan than the heat emanating from the probe during radiofrequency ablation, and cold can be used more easily than heat in areas that may be close to organs that could be damaged, allowing a physician to avoid those areas more easily.


One exception, however, is the lungs.


You can see the ice ball better in almost every organ except the lungs because the lungs are similar in color to the ice ball on the CT image, Symington says.


Cryoablation also is an alternative to reduce the pain of patients with cancer that has metastasized to bone, often when they cant physically tolerate any more chemotherapy. He says that use can be very successful for reducing pain if a physician can find and freeze the area from which the pain is emanating.


Though surgical ablation has been in use for some time, and Symington himself has been practicing percutaneous radiofrequency ablation for several years here, he says its scope is expanding rapidly, along with the practice of interventional radiology in general.


Symington says he thinks its just a matter of time before a lot of surgical treatment of tumors is supplanted by the ablation techniques, and he says the possibilities continue to expand. The procedure is just beginning to be used in some places around the country for treatment of breast tumors, though Inland Imaging is not yet doing that. Symington says a lot of patients even feel better about having surgery after ablation, knowing that less invasive techniques were tried first.


Contact Jeanne Gustafson at (509) 344-1264 or via e-mail at jeanneg@spokanejournal.com.