UNC PHYSICS AND ASTRONOMY COLLOQUIUM
F. Avraham Dilmanian, Ph.D.
Departments of Radiation Oncology, Neurology, and Radiology
Stony Brook University Medical Center, Stony Brook, New York
“Experimental radiation therapy projects with arrays of parallel, thin planes of synchrotron x rays and carbon ion beams”
The studies to be discussed are all based on the tissue-sparing effect of very small, or thin, beams of radiation. The effect, discovered first at Brookhaven National Laboratory (BNL) in the 1950s with 25-µm-diameter deuteron beams, was revisited in the early 1990s, also at BNL, this time with arrays of parallel, 25-37-µm thick planes of synchrotron x rays (called microbeams) at the National Synchrotron Light Source (NSLS). It was shown that single exposure of the rat cerebellum to such beam arrays at 75-µm beam spacing at 250 Gy dose does not produce any visible damage in three months using H&E histology. The study inspired a large series of studies both at the NSLS and at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Some of the milestones in the field that happened since then include a) a study at the NSLS showing that beams as thick as 0.68 mm (called minibeams) still retain much of their tissue-sparing effect, b) minibeams of carbon ion beams also spare tissues, c) minibeams of x rays and carbon ions aimed at the target from 90-degree angles cane be interleaved to produce a solid radiation field at the target, and d) irradiation of the rat spinal cord contusion injury with arrays of parallel synchrotron x rays temporarily improves their back-leg function. These topics together with the potential of the method in clinical medicine will be discussed.
Talk to be held at Radiation Oncology Department! This is not going to be a Physics Department Colloquia!!!