New X-Ray Method Could Improve Radiation Therapy -- MEDICA - World Forum for Medicine

The results on the improved method, which was tested in rats, were achieved by the U.S. Department of Energy’s Brookhaven National Laboratory and colleagues at Stony Brook University, the IRCCS NEUROMED Medical Center in Italy, and Georgetown University

The technique, microbeam radiation therapy (MRT), previously used a high-intensity synchrotron x-ray source such as a superconducting wiggler at Brookhaven’s National Synchrotron Light Source (NSLS) to produce parallel arrays of very thin planar x-ray beams (25 to 90 micrometers) instead of the unsegmented, broad beams used in conventional radiation treatment.

But, only certain synchrotrons can generate its very thin beams at adequate intensity, and such facilities are available at only a few research centers around the world. “The new development seeks a way out of this situation,” explained Brookhaven scientist Avraham Dilmanian, lead author of the new study. In the paper, the scientists report results that demonstrate the potential efficacy of significantly thicker microbeams, as well as a way to “interlace” the beams within a well-defined “target” inside the subject to increase their killing potential there, while retaining the technique’s hallmark feature of sparing healthy tissue outside that target.

First, they exposed the spinal cords and brains of healthy rats to thicker microbeams (0.27 to 0.68 millimeter) at high doses of radiation and monitored the animals for signs of tissue damage. After seven months, animals exposed to beams as thick as 0.68 millimeter showed no or little damage to the nervous system.

“This demonstrates that the healthy-tissue-sparing nature of the technique stays strong at a beam thickness that is within a range that could be produced by specialised x-ray tubes of extremely high voltage and current,” Dilmanian said. Such x-ray sources may allow the implementation of the method in hospitals.; Source: Proceedings of the National Academy of Sciences