Historic Breakthrough

30 years ago, UF team unlocked the mystery of radiosurgery

Medical physicist Frank Bova, Ph.D., left, and William A. Friedman, M.D., have been working on radiosurgery at UF since the 1980s.

Medical physicist Frank Bova, Ph.D., left, and William A. Friedman, M.D.,
have been working on radiosurgery at UF since the 1980s.

By ~ Michelle Koidin Jaffee

Each evening, neurosurgeon William A. Friedman, M.D., and medical physicist Frank Bova, Ph.D., would meet to begin another hourslong shift of sorts: designing and assembling a new machine bolt-by-bolt.

Their pursuit? To find a more effective, less invasive treatment for certain brain tumors and other devastating disorders of the brain.

The year was 1987. Inspired by a then-new system called the Gamma Knife that Friedman and Bova had observed in Stockholm, Sweden, and another new system called a linear accelerator they had observed at Harvard University, Friedman and Bova led a University of Florida team in setting out to design and build their own system. They sought to precisely target diseased tissue with focused, high-energy radiation beams while sparing the surrounding healthy tissue.

Toiling till midnight for more than a year, Friedman, then 35, and Bova, then 38, unveiled their new radiosurgical system on May 18, 1988. They used it to treat UF’s first radiosurgery patient, a woman who had an arteriovenous malformation, or AVM, which is a dangerous tangle of blood vessels in the brain.

That patient was cured, and now, as Friedman and Bova mark the 30th anniversary of their UF-patented invention that brought radiosurgery to the Southeast and to more than 200 hospitals across the country and world, they count more than 4,500 patients treated by their team. The number of journal articles they’ve published on this incredible breakthrough now tops 175.

“Prior to that point in 1988, patients with these challenging brain problems had a limited number of options,” said Douglas Kondziolka, M.D., director of the Center for Advanced Radiosurgery at NYU Langone Health. “Bill Friedman and Frank Bova were instrumental in developing new radiosurgery technologies with linear accelerators to create a hospital-based, patient-friendly effective concept to treat a wide variety of brain disorders. They were able not only to treat patients, but they were leaders in the publication of their results and sharing outcomes with the medical community.”


Today, radiosurgery is a common outpatient procedure used to treat certain benign and malignant brain tumors, AVMs and facial pain disorders.

At UF Health Shands Hospital, radiosurgery is performed in the radiation oncology unit, and on any given Wednesday as many as 11 patients undergo the treatment. Patients receive numbing injections to the scalp in order to be fitted with a metal halo to keep the head in proper position. The procedure that once lasted all day now takes less than three hours.

Radiosurgery at UF Health is performed using a linear accelerator, a device in which charged particles are accelerated by successive impulses. The treatment involves focusing hundreds of small beams of radiation on a target in the head. Each one of the beams goes through a different pathway, coming together at the target. The radiation damages cellular DNA so that cells die when they try to divide.

“So the target gets roughly 100 percent of the radiation,” said Friedman, the longtime chair of neurosurgery who in November was honored with selection to the UF College of Medicine Wall of Fame. “Each normal brain pathway gets 1 percent, which is harmless.”

A comprehensive review of 2,369 patients published in 2014 found there was no increased risk of malignancy anywhere in the body following linear accelerator stereotactic radiosurgery compared with the general population. The study, led by UF neurosurgeon Maryam Rahman, M.D., in collaboration with Friedman and Bova, was published in the journal Stereotactic and Functional Neurosurgery.


But in the 1980s, Bova had to solve a problem: The linear accelerator of that time — which evolved from World War II technologies used for radar — was not sufficiently accurate for radiation to the brain. He had to figure out a way to improve the accuracy to within a fraction of a millimeter.

“Frank then came up with a mechanical system that eliminated the inherent inaccuracy of the linear accelerator,” Friedman said. “Frank came up with his own design and UF patented it, and that became the central part of subsequent linear accelerator systems.”

Together with computer programmer Russell Moore, Bova then developed the first true computer-dose planning system for radiosurgery. “Some people tried to force more generalized computer systems to do radiosurgery calculations,” Bova said. “We decided to make a system that was tailored to radiosurgery. We took five-and-a-half to six-hour calculations and got it down to 90 seconds.”

The UF linear accelerator device became the first approved by the Food and Drug Administration for use in radiosurgery, Bova said.
In July 2018, the American Association of Physicists in Medicine honored Bova with the Edith Quimby Lifetime Achievement Award for his outstanding contributions to medical physics.

“Developing a radiosurgery system has helped change the way neurosurgery is practiced for the better — all over the world,” Friedman said. “But where it really counts is just one patient at a time. That’s the most important part.”