Effect of 14 MeV Monoenergetic Neutrons on HeLa and P388F Cells in Vitro

Summary

The effects of 14 meV monoenergetic neutrons were compared with those of 300 kV x-rays. Cell survival data were used to compute dose-response curves from which values of oxygen enhancement ratio (OER) and relative biological effectiveness (RBE) have been derived. The OER for HeLa cells was 1·51 with neutrons and 2·39 with x-rays; giving a gain factor of 1·58. The RBE for HeLa cells varied between a value of 4·3 at the 90 per cent level of cell survival to 2·3 at the 3 per cent level. The RBE can be assumed to fall to a constant value of 1·95 at lower levels of survival. A constant value of 1·9 was determined for the RBE for P388F mouse lymphoma cells.