When Nancy Liebrecht had a brain tumor removed last summer, doctors at the University of Maryland Medical Center told her that she would need radiation to zap the 10 percent of the slow-growing mass they couldn't remove.
The Baltimore architect could have had conventional radiation immediately but opted to wait until a new center opened offering a more high-tech therapy. The $200 million privately funded, but university-affiliated Maryland Proton Treatment Center may be able to target her tumor more precisely and powerfully while sparing the rest of her healthy brain.
"Once I heard it wouldn't destroy the good cells with the bad, I was all for it," said Liebrecht, 42, just before her 12th of 18 radiation sessions. "Eventually, killing good cells could mean problems with vision, hearing and memory."
About 60 percent of all cancer patients have radiation, usually after surgery, to kill remaining cells. And, though many studies are in the works to understand who may benefit most from typically more costly proton radiation treatments, the promise of the newer technology has lead to a boom in construction of the expensive facilities and interest from patients like Liebrecht who hope for better outcomes and fewer side effects.
Located in a 110,000-square-foot building in the university's West Baltimore BioPark, the Maryland center opened in February and is one of 22 such facilities already operating nationwide. About 15 more are planned.
Both proton and conventional X-ray radiation hobble cancer cells in much the same way, but the promise of proton therapy is that it causes less harm in areas near the cancer. Conventional radiation doses everything in its path to the tumor site and beyond.
Still, for most patients, a low dose of conventional radiation is enough to do the job and damage little along the way. But when higher doses of radiation are needed to tackle more complex and aggressive tumors, or when the cancer is near sensitive organs, for example, doctors have been hamstrung.
Proton therapy offers a possible solution. But it's no small task. At the center, a massive 90-ton cyclotron accelerates positively charged protons, which then are directed by a strong magnetic field into a pencil-sized beam and aimed accurately at a tumor through 3D imaging. Most of the energy is released in the tumor, minimizing the damage to healthy cells on the way in and impacting nothing beyond, unlike conventional radiation.
The U.S. Food and Drug Administration approved proton therapy in 1988 and the first center opened in California in 1990, according to the National Association of Proton Therapy.
Investors with California-based Advanced Particle Therapy, which also opened a center in San Diego and is developing two others in Atlanta and Dallas, approached the University of Maryland about operating a new center about a decade ago, said Dr. William F. Regine, chair of the School of Medicine's department of radiation oncology and executive director of the proton center.
"In 70-80 percent of cases the low dose of radiation to surrounding tissue is insignificant, but on the flip side, in 20-30 percent of cases, we need a higher dose of radiation and that will cause injury to surrounding tissue," Regine said. "We'd been sending those cases to other proton centers."
He said some patients would obviously benefit, but studies are needed to determine the range of cancers.
There are several trials underway, including one lead by Dr. Jason A. Efstathiou, director of the genitourinary division of the department of radiation oncology at Massachusetts General Hospital, which has operated a proton center for years. He's trying to determine if quality of life improves for prostate cancer patients when they are given proton therapy over conventional radiation, and if the improvements are enough to justify the increased cost.
To encourage insurers to approve the therapy every time it's recommended, Regine said the Maryland center doesn't plan to charge any more for proton therapy than conventional radiation treatment costs.
The cost of proton therapy varies among states and insurers, but a 2012 study in the Journal of the National Cancer Institute found that the median insurance reimbursements were $32,428 for proton therapy compared with $18,575 for conventional radiation. Some insurers scoff at paying more for benefits that aren't proven, which Efstathiou said is hampering efforts to even collect reliable data.
He said about 150 men are enrolled or approved to participate in his study conducted at multiple centers, and the Maryland center expects to join the effort to ultimately enroll 400.
There are other trials ongoing to determine the long-term benefits for breast and lung cancer patients, among others. Researchers will try to show if there are higher cure rates, lower rates of recurrence and fewer side effects that mean less costly follow-up care, as well as qualify of life improvements. That will determine which patients could be approved for proton therapy, and the financial viability of proton centers.
"We all want judicious use of treatment," Efstathiou said. "People who would benefit should receive that treatment. The challenge is figuring out who are those patients. When it comes to proton therapy we're still in the active stage of figuring that out."
Already, studies show benefits for pediatric patients, adults with a common kind of eye tumor and those with complex and difficult-to-treat tumors, according to the American Society of Radiation Oncologists, which recommends insurers pay for treatment of people with these cancers, as well as those enrolled in clinical trials like Efstathiou's.
Dr. Sameer R. Keole, an assistant professor of radiation oncology at the Mayo Clinic in Arizona and a society board member, said with brain tumors, for example, proton therapy reduces the dose to healthy tissue by 50 to 90 percent. That can mean preservation of cognitive abilities.
In some breast cancers, the dose can be reduced up to 90 percent, which may translate into lower risk of heart attack, he said. And because radiation can have effects over time, those with long life expectancies such as children and young adults are good candidates for proton therapy.
Currently, only one percent of patients receive proton therapy, so Keole said there was room for more centers.
"I expect the ongoing clinical trials will show a benefit for proton therapy in some percentage of patients," he said. "It's hard to say what number. I think it will be higher than 15 percent. I'm skeptical it will be higher than 40 percent. What this means, is that traditional X-ray therapy will continue to be the mainstay of radiation therapy for the foreseeable future."
Regine, of Maryland's school of medicine, said for some patients, there is no debate about which treatment is best.
Jim Schumacher, 62, of Seattle is an example. He has chordoma, a rare type of cancer that occurs on the spine. Most of his cancer was removed last year when it was discovered during surgery. Several disks and vertebrae also were removed and replaced with metal rods and spacers. He was referred to chordoma experts at Maryland for follow-up and was relieved to also have access to a proton center. Conventional radiation would have ruined his kidneys.
"I don't know what would have happened if this was 10 years ago," he said alluding to when there was less access to proton therapy. "Proton radiation is my best and only choice."
Regine's team is working on protocols to guide doctors in choosing the 20-30 percent of Maryland radiation patients that most likely would benefit from proton therapy. He also is working on partnerships with several area institutions to expand access to the treatment and funnel enough patients — up to 200 a day eventually — to make the center financially viable.
A high volume of patients will be needed because the Maryland center doesn't plan to charge a premium for it.
"The biggest thing I can do for patients is give them hope and that goes with having every available tool in my tool box," he said. "And until now I didn't have this tool. We want to make this as widely accessible as possible."