Improving Treatments for Brain Cancer Patients

As a radio designer, I was interested to see an improvement in monitoring a treatment for brain tumors.  Unfortunately, the article doesn't have a very clear explanation of how the system operates.

One of the first folks I met when I moved here to the Silicon Swamp in 1982 was another ham who was a very outgoing, friendly guy.  We became good friends, and since he was a single guy living here with no family, he spent a lot of holidays with us.  He was diagnosed with a brain tumor in the mid '00s.  From the first symptom, suddenly being unable to lift his foot onto a raised sidewalk at a weekend radio licensing class, until his death was less than two weeks.  The article quotes the American Brain Tumor Association saying that this year 80,000 Americans will be diagnosed with a brain tumor.  Of those, 16,000 will die.

One of the treatments for a brain tumor that is becoming more widely used is radio frequency ablation (RFA), a way of heating the tumor to a temperature that helps kill it.  It's used as an adjunct (additional treatment) to the more conventional "slash and poison" 1-2 punch of surgery and chemotherapy. 

RFA is a minimally invasive procedure that uses electrical energy to destroy cancer cells with heat. A thin needle is inserted into the brain and delivers radio frequency waves directly to the tumor. This in turn heats the tumor to 140℉ until the tumor is destroyed. While this method is less invasive and becoming more popular, doctors are still lacking a method for monitoring the procedure in real-time.

In other words, like the popup timer in a Thanksgiving turkey breast, how do they know the brain tumor has been hot enough long enough?  Research Assistant Professor John Stang in the Department of Electrical Engineering at the University of Southern California points out that there's no commonly used way to monitor the temperature inside the tumor, often buried deep inside the brain.

“Although ablation is becoming increasingly popular, there is still no thermal imaging technology in regular clinical use to monitor these procedures in real time and ensure that the correct thermal dose is delivered the first time,” said Stang.

Stang co-authored the study published in IEEE Transactions on Biomedical Engineering, along with Mahta Moghaddam, director of the Microwave Systems, Sensors, and Imaging Lab (MiXIL); Guanbo Chen, from the University of Southern California; Mark Haynes, from the NASA-Jet Propulsion Laboratory; and Eric Leuthardt, from Washington University in St. Louis. Stang and Moghaddam have developed a real-time thermal imaging method and device that will aid in the accurate delivery of RFA treatments.

The article doesn't say much about the method they developed, just that they beam a microwave transmitter into the patient's head and by monitoring the reflections from the brain tissue, calculate changes to the dielectric properties of the brain tissue.  Apparently, they discovered a relationship between the increasing temperature and the dielectric properties and can determine when the tumor has reached the proper temperature.  The reflections are heavily processed to give a color-coded visual representation of the tumor temperature. 

At this point in the research, they're not working on human patients, just in vitro (in glass); experiments on things such as tissue cultures.  They hope to be a few years from clinical trials. 

“In in vitro experimental validation studies, our system was able to achieve 1°C accuracy at a refresh rate of one frame per second,” Stang said. ...  “Assuming we get good results, we may be three to five years away from clinical trials,” said Moghaddam.