A Comparison of Cs-137 γ Rays and 320-kV X-Rays in a Mouse Bone Marrow Transplantation Model

• Published in: Dose-response 2020-04, Vol.18 (2), p.1559325820916572-1559325820916572
• Main Authors: Gott, Katherine M., Potter, Charles A., Doyle-Eisele, Melanie, Lin, Yong, Wilder, Julie, Scott, Bobby R.
• Format: Article
• Language: English
• Subjects: 320-kV X-rays; Bone marrow; Cs-137 γ rays; Cytotoxicity; Original; Radiation; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; spleen; Stem cell transplantation; X-rays
• ISSN: 1559-3258; 1559-3258
• DOI: 10.1177/1559325820916572

US homeland security concerns regarding the potential misuse of some radiation sources used in radiobiological research, for example, cesium-137 (137Cs), have resulted in recommendations by the National Research Council to conduct studies into replacing these sources with suitable X-ray instruments. The objective of this research is to compare the effectiveness of an X-RAD 320 irradiator (PXINC 2010) with a 137Cs irradiator (Gammacell-1000 Unit) using an established bone marrow chimeric model. Using measured radiation doses for each instrument, we characterized the dose–response relationships for bone marrow and splenocyte ablation, using a cytotoxicity-hazard model. Our results show that the X-RAD 320 photon energy spectrum was suitable for ablating bone marrow at the 3 exposure levels used, similar to that of 137Cs photons. However, the 320-kV X-rays were not as effective as the much higher energy γ rays at depleting mouse splenocytes. Furthermore, the 3 X-ray levels used were less effective than the higher energy γ rays in allowing the successful engraftment of donor bone marrow, potentially as a result of the incomplete depletion of the spleen cells. More defined studies are warranted for determining whether bone marrow transplantation in mice can be successfully achieved using 320-kV X-rays. A higher X-ray dose then used is likely needed for transplantation success.