It looks like proton therapy will be developed into a compact device, after a technology transfer agreement between Lawrence Livermore National Laboratory and TomoTherapy Inc., a Madison, Wisconsin company, was announced just a few days ago.
From the Lawrence Livermore NL press office:
“This technology has grown out of work to develop compact, high-current accelerators as flash X-ray radiography sources for nuclear weapons stockpile stewardship,” said George Caporaso, the lead scientist on the project at Lawrence Livermore. “We are excited about applying this new technology to the field of cancer treatment, to make proton therapy widely available as a treatment option.”
“We have taken proton therapy and achieved major advances toward what we were told was impossible – to scale it down to a size and price that will bring it in reach of every major cancer center,” said Ralph deVere White, director of UC Davis Cancer Center and associate dean for cancer programs. “Our research partnership with Lawrence Livermore National Laboratory has fulfilled the mission for which it was created: to deliver translational research in order to advance health care.”
Conventional radiation therapy kills cancer cells using high-energy X-rays. These X-rays deliver energy to all the tissues they travel through, from the point they enter the body, until they leave it. Doctors therefore have to limit the dose delivered to the tumor to minimize damage to surrounding healthy tissue.
Unlike high-energy X-rays, proton beams deposit almost all of their energy on their target, with a low amount of radiation deposited in tissues from the surface of the skin to the front of tumor, and almost no “exit dose” beyond the tumor. This property enables doctors to hit tumors with higher, potentially more effective radiation doses than is possible with gamma radiation…
The compact system is expected to fit in standard radiation treatment suites and to cost less than $20 million. The compact system will be mounted on a gantry that rotates about the patient.
Caporaso’s team overcame the size obstacle by using dielectric wall accelerator technology developed through defense research. The Livermore scientists have demonstrated in principle that this technology will enable proton particles to be accelerated to an energy of at least 200 million electron volts within a light-weight, novel, insulator-based structure about 6.5 feet long. It also won’t use any bending magnets, and will be able to change the protons’ energy and intensity between each burst that occurs many times per second.
Currently available proton therapy machines use cyclotrons or synchrotrons nearly 10 feet in diameter and weighing up to several hundred tons. This equipment includes the enormous gantry and bending magnets necessary to focus and direct the beams onto patients.
In addition to overcoming size and cost obstacles, the compact system will improve on existing full-scale systems by including the capability to vary the energy, intensity and “spot” size of the proton beam. Radiation will be produced in rapid pulses, creating small “spots” of dose throughout the tumor. Currently only one proton facility in the world, the Paul Scherrer Institute in Switzerland, is able to deliver this intensity-modulated proton therapy (IMPT). IMPT is generally considered the best way to destroy tumors while minimizing damage to surrounding healthy tissue.
Press release: First compact proton therapy machine for cancer treatment enters development …
Press release: TomoTherapy Inc. and Lawrence Livermore National Laboratory to Develop Proton Therapy System …
Flashbacks: Activate the Proton Beam ; The Physics of Proton Therapy; In the Works: Proton Treatment from MIT