(Inside Science TV) -- For more than 50 years, Karen Smith had been living life to the fullest. Then one day it all changed.
"I was just getting headaches a lot which was unusual for me," said Smith.
Smith was diagnosed with a brain tumor called glioblastoma, a common and aggressive type of brain cancer. Even with treatment, it can come back.
"I just had a funny feeling there was something going on," Smith said.
Currently available treatments for glioblastoma -- including brain surgery, radiation and chemotherapy, do not kill the entire brain tumor. Now, Smith is part of clinical trial to test a new device that fits on her scalp and delivers low-intensity electrical pulses to the tumor site.
"It prevents the division of tumor cells and by doing that it causes the tumor cells to die," said Samuel Goldlust, a neuro-oncologist at the John Theurer Cancer Center at Hackensack University Medical Center in New Jersey.
One of the reasons cancer cells are deadly is because they divide out of control. The cap delivers electric pulses at just the right intensity and frequency to disrupt cancer cell division. Healthy brain cells divide less frequently, so those cells are unharmed, while the rapidly-dividing cancer cells die off.
"Subsequently, if enough tumor cells die, then the tumor can start to shrink," said Goldlust.
The device is portable and battery powered, allowing patients to lead normal lives and spend more time with family. For best results, doctors advise patients to wear the cap for at least 18 hours a day.
"If you can wear this three-quarters of the time, it's going to have a much better chance to help you than if you don’t," Goldlust said.
After more than a year of using the cap, Smith's tumor has shrunk.
"So far, so good," Smith said.
The Food and Drug Administration has only approved the device for patients who have recurrent cases of glioblastoma. While it is not a cure, it improves quality of life, and has fewer side effects than radiation and chemotherapy.
The device is designed to be used over the course of months as an addition to conventional treatments.