The influence of reference radiation photon energy on high-LET RBE: comparison of human peripheral lymphocytes and human-hamster hybrid A(L) cells

Schmid, T. E.; Greubel, C.; Dollinger, G. and Schmid, E. (2017): The influence of reference radiation photon energy on high-LET RBE: comparison of human peripheral lymphocytes and human-hamster hybrid A(L) cells. In: Radiation and Environmental Biophysics, Vol. 56, No. 1: pp. 79-87

Abstract

The relative biological effectiveness (RBE) based on the induction of dicentrics in any cell type is principally an important information for the increasing application of high-LET radiation in cancer therapy. Since the standard system of human lymphocytes for measuring dicentrics are not compatible with our microbeam irradiation setup where attaching cells are essential, we used human-hamster hybrid A(L) cells which do attach on foils and fulfil the special experimental requirement for microbeam irradiations. In this work, the dose-response of A(L) cells to photons of different energy, 70 and 200 kV X-rays and Co-60 gamma-rays, is characterized and compared to human lymphocytes. The total number of induced dicentrics in A(L) cells is approximately one order of magnitude smaller. Despite the smaller alpha and beta parameters of the measured linear-quadratic dose-response relationship, the alpha/beta-ratio versus photon energy dependence is identical within the accuracy of measurement for A(L) cells and human lymphocytes. Thus, the influence of the reference radiation used for RBE determination is the same. For therapy relevant doses of 2 Gy (Co-60 equivalent), the difference in RBE is around 20% only. These findings indicate that the biological effectiveness in A(L) cells can give important information for human cells, especially for studies where attaching cells are essential.

• Item Type: Journal article
• Faculties: Medicine
• Subjects: 600 Technology > 610 Medicine and health
• ISSN: 0301-634X
• Language: English