To learn more about clinical trials, brain tumor treatments and the physicians featured in this story, go to www.uchospitals.edu/specialties/cancer/brain.

Scorpion venom saving lives. A local hospital was testing the theory and was surprised by the positive results until the money for the study ran out.

Most people would be afraid of this -- the death stalker scorpion. Now imagine doctors telling you they wanted to inject its venom into your veins.

Donna Van Ryn, Brain Tumor Patient: "I didn't really want to do that because I was very afraid of something like that."

But after mutliple surgeries, multiple chemotherapies and still growing cancer in her brain, Donna Van Ryn knew she had no other option.

Donna Van Ryn: "I've gone through everything they had to offer so far. And none of it seemed to last very long."

So at the request of her doctors, Donna entered a clinical trial -- using a drug derived from scorpion venom attached to radiation to target cancer.

Dr. Steven Chmura, radiation oncologist, University of Chicago Medical Center: "As opposed to our normal types of radiation therapy that has to go through the skin, the hair, the brain everything else, this is going directly to the sight of the tumor and giving a very, very high dose."

"It binds to glioma cells or brain tumor cells."

Meaning the radiation attacks individual cancer cells while sparing the rest of the body.

"We are able to use this carrier agent almost like a smart bomb type of agent to actually bring a piece of radiation right to each and every tumor cell."

But it is toxic for patients. Donna couldn't walk or talk. Therapy and determination brought her back.

Donna Van Ryn: "After you come out of it it can be very frightening because it's almost like starting all over again."

And scans show she has the chance to do just that. The cancer that was continually growing has now stopped.

Dr. Rimas Lukas, Neuro-oncologist, University of Chicago Medical Center: "Here we have on the left a scan from a number of months ago and a more recent scan here which looks relatively unchanged."

It appears the death stalker venom has extended Donna's life.

Donna Van Ryn: "I'm feeling good most of the time. It's very exciting!"

What is frustrating is doctors don't know exactly why the scorpion venom worked in Donna not just to deliver radiation but also to fight the cancer itself. It didn't work as well for others and now they want to do more research... but the funding was cut off. Doctors hope other people's chances of living longer haven't been cut off as well.