Biological response to radiation therapy.

In an investigation by the Swedish Cancer Society, the present status, critical issues and future aspects and potentials were described by an expert group for each of nine major areas of radiation therapy research. This article deals with biological response to radiation. Separate sections deal with molecular responses to radiation, the stem cell and clonogenic cell concepts and the importance of cell proliferation, cell and tissue responses to doses above and below 1 Gy, respectively, the potential role of intercellular signalling pathways, the so-called bystander effect and radiation biology-based therapy planning and treatment optimization.