by Mike Sharkey
The University of Florida’s new Proton Therapy Institute is pure Sci-Fi channel meets Discovery. It’s a marvel of modern physical engineering hidden behind nondescript glass walls, all of which is tucked into one of the most blighted areas of Jacksonville. If the technology behind the facility isn’t mind-boggling enough, the numbers are:
• $125 million (same as the Arena)
• 98,000 square feet
• 18-foot thick walls in places that prevent radiation exposure
• a cyclotron that weighs 440,000 pounds and had to be welded to the bottom of a boat to get here
• proton accelerators capable of drawing up to one megawatt of electricity (that’s one million kilowatts, enough to run 4,300 TVs at one time)
• several 4,000-pound doors
Enough of the numbers. What is proton beam therapy and how does it work?
“It’s state-of-the-art radiation therapy,” said Stuart Klein, the executive director, assistant dean and lecturer for the proton therapy institute, which is located at Shands Hospital, but is primarily a UF-owned and -operated facility. “It’s less damaging and there are fewer side effects. We are hoping it makes for higher cure rates.”
In layman’s terms the process works like this: the oxygen is stripped from water (which consists of two parts hydrogen and one part oxygen). The electrons within hydrogen are then stripped, leaving pure hydrogen protons. Those protons are injected into the bottom of a 440,000-pound cyclotron that spins them at 95-97 percent of the speed of light (186,000 miles/second).
“The inside of the cyclotron looks like an orange cut in half horizontally,” said Klein, explaining the “sections of the orange” inside the cyclotron are various-strength magnets. “It changes the polarity and the protons are kicked around faster.”
The protons are ejected out of the cyclotron and pass through what’s called a degrader — a dense piece of carbon graphite that’s used to slow the particles to a usable and manageable speed.
“There’s an 18-and-a-half-foot thick concrete wall surrounding the cyclotron,” said Klein. “It’s the most radioactive part of the building.”
A series of magnets steer and focus the beam into one of four proton accelerators, called gantries, within the facility. Then the treatment begins.
Klein explained there are several advantages to proton beam therapy, not the least of which is the lack of intrusion and damage done to the body.
In conventional radiation treatment, the body is penetrated by radiation which is focused on the tumor. Radiation damages healthy tissue upon entry before getting to the cancerous tumor. A certain percentage of healthy tissue is also damaged upon exit from the body.
In proton therapy treatment, the radiation enters the body at a lower dosage, peaks at the tumor and then is programmed to essentially stop and there is little to no damage to healthy tissue.
One of the final pieces of the engineering puzzle involves a brass aperture. It’s similar to the device in a camera lens that regulates the amount of light that enters the camera. The aperture weighs 30-40 pounds and is slightly bigger than a softball. A hole is milled through the aperture the exact dimensions of the tumor.
“The doctor basically writes a prescription for it,” said Klein, explaining that the aperture is only prescribed after the tumor has been located through an MRI (magnetic resonance image) or CT scan (computed tomography imaging scan). This image tells doctors the exact size, shape, location and depth in the body of the tumor. A Lucite mold is also used with the aperture. “It’s a 3-D relief of the tumor. It defines where the protons stop. It tells us where the patient’s tumor is, its size, shape and direction.”
The use of proton therapy to treat cancer patients isn’t revolutionary, but the technology, physics and engineering are.
“This technology has actually been around since 1954,” said Klein. “Doctors then couldn’t visualize where the tumor was. We have improved the diagnostics through MRIs and CT scans and we are now taking advantage of that.”
The institute will start seeing patients Aug. 7 and Klein said there’s already a waiting list. The center will treat prostate, pediatric, head/neck, lung and brain cancer. Six months from now, they will begin using the second proton accelerator.
“In about two-and-a-half years we will be fully ramped up. There will be two shifts a day, six days a week,” said Klein. “We will be able to treat 200 patients a day.”
Despite all the funding and all the brains, the institute is still facing a major hurdle — housing for patients that resembles home more than a hotel. With most stays running 4-6 weeks, Klein said UF is looking to partner with a local developer to build housing. Klein said UF has been working with Mack Bissette of SRG Homes who is renovating homes in Springfield, but there’s nothing definite in the works.