Increased cell survival and cytogenetic integrity by spatial dose redistribution at a compact synchrotron X-ray source

• Published in: PloS one Vol. 12; no. 10; p. e0186005
• Main Authors: Burger, Karin, Ilicic, Katarina, Dierolf, Martin, Günther, Benedikt, Walsh, Dietrich W M, Schmid, Ernst, Eggl, Elena, Achterhold, Klaus, Gleich, Bernhard, Combs, Stephanie E, Molls, Michael, Schmid, Thomas E, Pfeiffer, Franz, Wilkens, Jan J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 19.10.2017; Public Library of Science (PLoS)
• Subjects: Aberration; Animals; Bioengineering; Biology and Life Sciences; Brain cancer; Cancer; Cell Survival; CHO Cells; Chromosome aberrations; Chromosome Aberrations - radiation effects; Chromosomes; Collimation; Complications; Cricetulus; Dosimetry; Elastic scattering; Engineering and Technology; Feasibility studies; Gene expression; Health risks; HeLa Cells; Humans; Irradiation; Laser applications; Lasers; Light sources; Medicine and Health Sciences; Methods; Microbeams; Oncology; Physical Sciences; Physics; Prevention; Radiation exposure; Radiation therapy; Radiotherapy; Survival; Synchrotrons; Translation; Tungsten; X ray sources; X-Rays; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0186005

X-ray microbeam radiotherapy can potentially widen the therapeutic window due to a geometrical redistribution of the dose. However, high requirements on photon flux, beam collimation, and system stability restrict its application mainly to large-scale, cost-intensive synchrotron facilities. With a unique laser-based Compact Light Source using inverse Compton scattering, we investigated the translation of this promising radiotherapy technique to a machine of future clinical relevance. We performed in vitro colony-forming assays and chromosome aberration tests in normal tissue cells after microbeam irradiation compared to homogeneous irradiation at the same mean dose using 25 keV X-rays. The microplanar pattern was achieved with a tungsten slit array of 50 μm slit size and a spacing of 350 μm. Applying microbeams significantly increased cell survival for a mean dose above 2 Gy, which indicates fewer normal tissue complications. The observation of significantly less chromosome aberrations suggests a lower risk of second cancer development. Our findings provide valuable insight into the mechanisms of microbeam radiotherapy and prove its applicability at a compact synchrotron, which contributes to its future clinical translation.