"Cryoablation has potential as a treatment for cancer that has spread to the lungs from other parts of the body and could prolong the lives of patients who are running out of options," said David A. Woodrum, M.D., Ph.D., an author of the study and interventional radiologist at the Mayo Clinic in Rochester, Minn. "We may not be able to cure the cancer, but with cryoablation we can at least slow it down significantly and allow patients to enjoy greater quality of life longer," he added. Metastatic lung disease is difficult to treat and often signals a poor prognosis for patients.
In the initial results of the study, called the ECLIPSE trial (Evaluating Cryoablation of Metastatic Lung/Pleura Tumors in Patients—Safety and Efficacy), 22 subjects with a total of 36 tumors were treated with 27 cryoablation sessions. Cryoablation was 100 percent effective in killing those tumors at three-month follow-up. Follow-up at six months on 5 of the 22 patients (23 percent) showed the treated tumors to still be dead. Cryoablation is performed by an interventional radiologist using a small needle-like probe guided through a nick in the skin to cancerous tumors inside the lung under medical imaging guidance. These tumors have spread—or metastasized—to the lung from primary cancers in other areas of the body. Once in position, the tip of the instrument is cooled with gas to as low as minus 100 degrees Celsius. The resulting halo of ice crystals can destroy cancer by interrupting its cellular function, protecting nearby healthy, delicate lung tissue. Lung cryoablation has been promising in part due to the low periprocedural morbidity.
"Most of these patients can go home the day after their cryoablation treatment and resume their normal activities," Woodrum said, noting that researchers plan to continue to follow patients for up to five years. While cryoablation is being developed for the treatment of metastatic lung cancer, the future looks brighter for individuals who once had nowhere else to turn, said Woodrum, who was assisted in research by Frank Nichols, M.D. and Matthew R. Callstrom, M.D.