A new collaboration between the United States Department of
Energy’s Brookhaven National Laboratory and Best Medical International (BMI)
aims to design one of the most dynamic and effective cancer therapy devices in
the world. The ion Rapidly Cycling Medical Synchrotron (iRCMS) draws on the
particle acceleration expertise of Brookhaven Laboratory physicists and the
medical experience of BMI to advance cancer therapy, particularly the evolving
use of carbon and other light ions.
“We believe a machine capable of delivering both protons and
carbon ions will fill the gap in the particle therapy available to cancer
patients in this country,” said Joseph Lidestri, a chief consultant for BMI and
senior scientist at the New York
Structural Biology
Center. “Ion therapy has
proven itself as a valuable option, providing improved control with less
collateral damage for patients with resistant diseases. This new device will
open new and potentially more effective pathways through carbon and other
ions.”
Synchrotrons, devices that accelerate particles along a circular
path by synchronizing magnetic and electric fields, have proven useful in
hospitals for their efficiency and ability to generate high quantities of
finely tuned particle beams. These energetic beams are used to bombard and
destroy cancerous tumors. The iRCMS, a 64-m particle racetrack, will be unique
in the field because it rapidly cycles at 15 Hz, allowing the ion beam to
deposit energy throughout an entire longitudinal column with each cycle. This
delivery method has the distinct potential to strike each layer of a cancerous
tumor in a single treatment cycle.
The partnership was formed under a Cooperative Research and
Development Agreement (CRADA), designed to link the private sector with the
unique capabilities of government research facilities. Ultimately, the research
and development funded by BMI and conducted at Brookhaven Laboratory will
provide the prototype for the iRCMS, which will lead to large-scale
manufacturing and installation in cancer treatment facilities.
“They’re depending on us for the accelerator design, and we’re
depending on them to tell us what the medical world needs,” said Derek
Lowenstein, associate chair for applications and education in Brookhaven Laboratory’s
Collider-Accelerator Department and the lead coordinator of the CRADA. “This
builds upon our history of invention and accelerator expertise, from the
Cosmotron in the 1950s to the Relativistic Heavy Ion Collider.”
Best Medical International, founded in 1977 in Springfield, Va.,
specializes in the development and manufacturing of a broad range of cancer
treatment technologies. Founder Krishnan Suthanthiran’s mission is to provide
the global medical community with high-quality, cost-effective treatment
options ranging from brachytherapy to particle therapy. There is a particular
challenge in delivering affordable advanced technologies such as ion therapy,
Lidestri said, which is why Suthanthiran decided to privately fund the
development of iRCMS at Brookhaven.
BMI first became interested in a partnership because of
Brookhaven Laboratory’s demonstrated skill with synchrotrons and a history of
pushing that technology into new frontiers. Physicists at the Laboratory made
earlier breakthroughs in advancing ion therapy, including patents on highly
efficient and compact particle-delivery systems.
The first phase of the CRADA generated a Conceptual Design
Report, initially expected to be a proton therapy synchrotron. But BMI
suggested early on that a more versatile machine, capable of firing carbon and
other ions, would be most beneficial to patients.
The efficacy of ion therapy is based upon the fact that the
energy of the proton and other ion beams can be adjusted so they deposit most
of their destructive energy directly on a cancerous tumor while leaving nearby
healthy tissue unscathed. X-rays, on the other hand, deposit large amounts of
energy over their entire pathway through human tissue. This results in healthy
tissue being damaged as the X-rays travel en route to the cancerous tissue and
after they exit the tumor. Charged ions minimize this collateral damage as they
can be tuned to spike at a specific depth, thus minimizing healthy cell damage
on either side of the targeted tumor.
Protons were the first particles used—and remain in widespread
use—but carbon offers more precise beams and reduces the scattering
characteristic of protons. The heavier carbon ions will require a maximum total
energy of 4,800 MeV to penetrate to depths of 27 cm, making this new
synchrotron larger and more demanding than the proton-only machines that
typically need only 206 MeV for comparable penetration. While carbon will
likely be the preferred particle for the new device, it will also be capable of
accelerating and aiming protons and other light ions should they prove more
viable for particle therapy.
Members of both teams emphasized that carbon ion therapy, which
has seen great success in Germany
and Japan
but needs further clinical testing, will not render other treatments useless. “This is another tool for doctors, a very advanced and complicated instrument
that we believe will prove unbeatable for a range of challenges,” Lidestri
said. “We’re not promising a cure-all or ‘silver bullet’ for cancer treatment,
but the iRCMS does have distinguishing features that will result in the
advancement of particle therapy.”
The collaboration is currently in phase two, with Brookhaven Laboratory
beginning to build a series of magnets, radio frequency acceleration cavities,
and a power supply for the rapid cycling of the synchrotron. The team expects
to have a working accelerator prototype in approximately three years, with the
addition of medical delivery hardware following shortly thereafter.
“We typically only build one-of-a kind machines,” said
Lowenstein, who has enjoyed the challenge of applying accelerator physics to a
problem immediately facing humanity. “In the end, BMI will take ownership of
the technology that we invent and provide this new treatment to patients at
several hospital locations.”
Added Lidestri, “The possibility to show that industries and
national laboratories can successfully collaborate and combine their strengths
on this scale—that will be a victory as important as completing the iRCMS.”