Published: Thu May 9, 2013
Baxter resident Lizah Martin was born with a hemangioma in her face and, in the early 60s, received an implant of tiny radioactive seeds to reduce the tumor and save her life. The tumor was removed when she was about one year old.
Decades later, Martin learned that the seeds were not removed with the tumor, as had been assumed. She had six removed in 2001. She thought only one remained, too close to her eye to safely remove.
With persisting headaches, Martin questioned whether remaining seeds might need to be removed. Her medical records were unclear on what the seeds were made of, how many were implanted, and how many might remain.
Her medical team, including medical physicist King Turnbull at Cookeville Regional Medical Center, needed answers to many questions before considering whether to remove any remaining seeds.
At the core of the decision was whether the seeds were comprised of radon or radium. The latter would still be radioactive and pose greater risks to remove than to leave in place. The implications would affect not only Martin, but surgeons who would need to take extra precautions to be protected from the radioactivity during the procedure.
Martin’s medical team needed to add a few members: Tennessee Tech University physics professors Ray Kozub and Mary Kidd.
“It was absolutely essential that we collaborate with Mary and Ray,” Turnbull said. “We didn’t have the tools to do this, and these guys are the gamma ray experts. They were essential in writing their report and being able to give us information on what’s in there, inside the patient.”
Kozub and Kidd had a refurbished gamma ray spectrometer that could measure the radiation emitted from Martin.
“We didn’t know how hot the seeds were, or the level of activity,” Kidd explained. Her task was to simply do for a person what she has done in research for years: Get a background measurement of the radiation in an empty room, then measure again with Martin seated at the spectrometer.
Radon, a radioactive gas, decays to lead-210 in less than a year. Lead-210 remains radioactive for a few decades. Radium, on the other hand, remains radioactive for more than 1,600 years.
“Within a couple of minutes, we saw peaks in the spectrum that matched the signatures of lead-210 and gold,” Kidd said. “The radiation from lead-210 interacts with gold and makes it fluoresce, so we knew the seeds were radon encapsulated in gold. We would have seen other signatures if the seeds had been filled with radium or if a different encapsulation had been used.”
Kozub and Kidd observed the gamma ray spectra for about an hour with Martin, then spent a few more hours analyzing the data to make sure their assessment was accurate.
“It was a once-in-a-lifetime opportunity to take something you use in basic research and see what’s going on inside a human being and help them,” said Kozub. “It was very rewarding.”
Turnbull sees the likelihood that medical physicists, surgeons and doctors will turn to scientists and university researchers for more assistance in the future.
“As medicine continues to grow, most of the research, as well as investigative and technical development work, is being performed by scientists,” Turnbull said.
“We always have an interest in medical imaging, and to be able to collaborate with Turnbull on a truly interdisciplinary effort was great,” said Kidd. “The human element, to actually be able to help a person, was really cool.”
TTU does not offer patient testing outside of a request from and collaboration with an accredited medical institution.
“I'm thankful that they had this one, specific piece of equipment, and that Mary recognized its value before it was relegated to the junk heap,” said Martin.