APPLICATIONS OF TECHNOLOGY:
- Carbon ion-beam cancer treatment
- Adaptable to proton ion-beam cancer treatment
- Heavy ion-beam accelerators
- Substantially smaller magnet
- Reduces weight of gantries 80%
- Enables carbon ion-beam equipment to fit in a proton-beam facility footprint
- Significantly lower cost
A team of Berkeley Lab physicists and engineers led by David Robin and Shlomo Caspi has designed a superconducting magnet that, at a fraction of the size and weight of conventional magnets, can bend a beam of heavy carbon ions around a 90° curve. The compact magnets made possible by this Berkeley Lab technology enable development of much smaller and less expensive carbon-ion beam equipment, which can be installed within planned or existing proton-therapy sites. Because this invention could drive down the high cost of treating inoperable tumors with pulses of accelerated carbon ions, it has potentially enormous practical implications for cancer therapy.
Critical to the new magnet design is the placement of a pair of overlapping solenoid coils, which are wrapped at a tilt, in two opposing directions, around the 90° curve of the donut-shaped (toroidal) beamline. When the coils are chilled to superconducting temperatures and a current is applied, they create magnetic fields strong enough to bend the ion beam. To determine how to precisely guide the stream of accelerating, heavy carbon ions around the curve through the toroid, the Berkeley Lab team used intensive computer modeling to simulate the required magnetic fields and to ascertain the optimal placement for the opposing coils as they wrapped around the toroid.
Carbon-ion therapy has been held back by its cost and the massive size of the gantries required to focus a high-energy carbon-ion beam precisely on the tumor site. Gantry size is directly related to the enormous weight of focusing magnets used to guide the beam from the accelerator to the patient. The Berkeley Lab technology reduces the weight of the largest of these magnets by 80 percent.
The use of carbon-ion beams to kill tumor tissue has been a promising avenue of cancer research since the initial experiments were conducted at Berkeley Lab’s Bevatron from 1977-1992. However, due to the extraordinarily high cost of carbon ion-beam facilities (~$250 million) only a handful have been built worldwide since the Bevatron was closed; none are in the United States.
Carbon-ion beam therapy has numerous clinical advantages over proton therapy, which targets tumors with a beam of lighter-weight hydrogen ions. Both forms of ion-beam therapy work by destroying the DNA of target cancer cells, but the heavier carbon ions can be focused more sharply, causing less damage to surrounding, healthy tissues. Carbon ions deposit more energy to the target, and thus can be delivered in smaller doses, in fewer visits. Clinical tests indicate that carbon-ion beams are more effective than proton beams for the treatment of tumors that thrive in a low-oxygen environment. Such “hypoxic” tumors are highly resistant to X-rays, making them ideal candidates for-ion beam therapy.
DEVELOPMENT STAGE: Early stage research.
STATUS: Patent pending. Available for licensing or collaborative research.
FOR MORE INFORMATION:
D. Robin, D. Arbelaez, S. Caspi, C. Sun, A. Sessler, W. Wan, and M. Yoon,
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 659, Issue 1, 11 December 2011, Pages 484-493.
Caspi, S, Dietderich, D.R., Ferracin, P., Finney, N.R., Fuery, M.J., Gourlay, S.A., Hafalia, A.R., “Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids,” IEEE Transactions on Applied Superconductivity, Vol. 17, part 2, pp. 2266-2269, 2007.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
REFERENCE NUMBER: IB-3054