Neutrons against cancer
25 years of neutron therapy at Fermilab
More than 150 people, including former patients from across the
United States, came to Fermilab on September 8 to celebrate a true
success story. Twenty-five years ago, the Neutron Therapy Facility
at Fermilab treated its first cancer patient.
The idea to build a medical facility at Fermilab developed in the early
1970s when physicians and physicists shared a vision: to wield
accelerator technology to combat cancer. Today, more than 3,100
patients have come to Fermilab in the hope of finding a cure for
some of the worst tumors known in the medical field.
Former patient Rahel Kent, who came to NTF in 1996, shared her
story with the audience, recalling how it all started.
"First it felt like a sore throat," she said. "Weeks later, half my throat
Physicians didn't immediately recognize the growing tumor. Soon,
however, Kent learned the shocking truth. At age 34, she had
developed salivary gland cancer, a rare disease usually associated
with older people who chew tobacco, a habit she had never
She was offered a devastating solution to the problem: Surgery that
would remove large parts of her jawbone, two-thirds of her tongue
and hopefully the entire tumor. It was unclear whether Kent would be
able to keep her voiceó or even stay alive.
"My articulation is the essence of what I do," said Kent, who works
as a criminal defense attorney in Los Angeles.
She decided to look for treatment alternatives and used the Internet
to find more information. After a few unsuccessful searches, she
finally made the right decision.
"I typed the words salivary gland cancer," she said. "I had eighteen
hits, nine from Fermilab."
She called Arlene Lennox, the head
of Neutron Therapy Facility at
Fermilab. Learning the details of
Kent's disease, Lennox asked her to
send copies of her medical records
to Dr. Jeffrey Shafer of Provena
Saint Joseph Hospital, which
operates NTF. Soon Kent received a
phone call from Shafer, and she
talked to him for three hours.
Eventually she received an
appointment for neutron treatment -
and she was cured.
"Dr. Shafer is not only one of the finest physicians, but also one of
the finest human beings I know," Kent enthusiastically described her
encounters with the physician. "He has a heart of gold."
Shafer is one of several physicians who treat patients at NTF and
continue to build upon a quarter century of beams for healing. On
September 7, 1976, Frank Hendrickson and Lionel Cohen were the
first physicians to treat a patient at NTF.
"Hendrickson took a leadership role," said Lennox. "He had to
address three constraints. First, neutron treatment could not
interfere with the high-energy physics program. Second, he had to
get his own money. And finally, the doctors had to head the
[medical] research and make the final decisions."
Hendrickson initially worked with Fermilab physicists Cy Curtis and
Don Young, who were very supportive of the idea to use a fraction
of the high-energy proton beam for medical purposes. After it
became clear that the Linac could accelerate and deliver more
protons than needed for the Main Ring accelerator, the Universities
Research Association, which operates Fermilab, provided 75,000
dollars of seed money and encouraged Hendrickson to obtain more
money from charities and other funding organizations.
With the help of Fermilab physicists, Hendrickson soon devised plans
for a new medical facility.
"In our first proposal, we wanted to do everything: protons,
neutrons, pions," recalled Hendrickson. "But it was considered much
too big by the National Cancer Institute. We then submitted a
scaled-down project with just neutrons."
The neutron proposal didn't require the construction of a new building
that would have cost more than a million dollars. Instead, it relied on
the conversion of a freight elevator, which technicians had used to
lower equipment into the accelerator tunnel, into a treatment room in
which patients could be lowered into a new neutron beamline to be
built. The National Cancer Institute approved the plan and provided
To create the neutron beam, Young and his colleagues designed and
constructed two magnets to divert a fraction of the Linac proton
beam, bend it around a ninety-degree curve and direct it toward a
beryllium target outside of the freight elevator. The 66-MeV protons
interact with the beryllium atoms and produce fast neutrons that
travel in the same direction as the original protons, eventually
entering the treatment room through a collimator, a concrete cylinder
with a hole at its center.
Positioning a patient in front of
the hole and choosing a
collimator with the right hole size,
NTF specialists can deliver
neutrons to a tumor of any size
while minimizing the exposure of
healthy cells to the beam.
Because the neutrons damage
cancerous cells much more than
any other form of irradiation, NTF
patients only need to receive one third of the number of treatments
compared to patients of photon or proton treatment centers.
To explain the differences in the various therapies, Hendrickson
compared photon (x-ray) and neutron beams of equal energy.
"The effect of photons is like one thousand ping pong balls entering a
room and bouncing around," he said. "Now put the same amount of
energy into one bowling ball. That's the neutrons. If they strike a part
of the DNA, it cannot be repaired by the cells. The damage done by
photons can often be repaired."
Because of cost, photon treatment is still the preferred form if
doctors decide to use irradiation. For tumors located near critical
nerves like the spinal cord or inside an eye, proton treatment has
proven to be very effective. The Loma Linda University Medical
Center, for which Fermilab built a proton accelerator in the late 80s,
treats about one thousand patients a year, one third of all proton
patients in the U.S. But for some types of cancer, referred to as
radioresistant tumors, both photon and proton therapies fail. Only
the more powerful neutron treatment provides the chance of
eliminating these tumors that are often inoperable and too large for
"The first NTF doctors went after those patients that had no other
options," said Lennox, who has worked at NTF since 1985. "Photon
treatment applies to about seventy percent of all cancer cases
treatable with radiation. In fifteen percent of cases, tumors are small
and close to critical structures, and proton beams are the most
effective. The final fifteen percent present hard to treat cases of
cancer. That's where neutrons are the treatment of choice."
To honor the work of the early pioneers, Lennox, who received an
award from Fermilab director Mike Witherell for her "vision,
commitment and compassion," presented on behalf of NTF an award
to Frank Hendrickson, who retired from NTF in 1995, as well as a
posthumous award to Lionel Cohen, who died in 1999.
"Hendrickson and Cohen took the medical program from research to
an accepted choice of treatment that Medicare and health
management organizations would pay for," Lennox said.
Lennox also presented a posthumous award to medical physicist
Miguel Awschalom, who had greatly contributed to the development
of NTF during its first ten years, and she announced that the
Honorable J. Dennis Hastert, Speaker of the U.S. House of
Representatives, would receive an award for "his support of the
Neutron Therapy Facility." Hastert, who had to cancel his ceremony
participation on short notice, has helped NTF to upgrade its facilities
with a computerized tomography scanner and secured funding for
The NTF now has the only vertical CT scanner in the U.S. "We now
can do CT scans of people sitting or standing, in exactly the position
in which they will receive neutron treatment," Lennox said, explaining
the significance of the new instrument.
Accelerators, however, remain one of the most important tools in the
battle against cancer. Former patients like Kent are proof for the
successful partnership of physics and medicine.
"Fermilab saved my life," she said.
by Kurt Riesselmann
On the Web:
Streaming video: Neutron therapy retrospective