Negative pion depth-dose profile examined by means of HeLa cell-survival curves.
HeLa cells were irradiated at liquid nitrogen temperature with negative pions from Nimrod at the Rutherford Laboratory and then assayed for survival of colony-forming ability. Complete dose-response curves were obtained from repeated determinations at 14 different positions along the depth-dose profile and survival curves were fitted to the data by computer programme. A depth-damage profile was thus established in terms of the final slopes of these survival curves. This confirmed the expected RBE value of 1.84 at the ionization peak. Although a value of unity was found in the main plateau region, the "entrance" positions showed significantly higher values.
D002470:Cell Survival / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004601:Elementary Particles; D006367:HeLa Cells / Q000528:radiation effects; D006801:Humans; D011829:Radiation Dosage; D012062:Relative Biological Effectiveness