Cellular damage and repair following heavy-ion irradiation

In this chapter, work done on the repair and expression of heavy-ion caused damage in mammalian cells in culture is summarized. Two distinct cellular processes occur with dose fractionation schemes: cells can repair sublethal damage, and can also be made more vulnerable by a preexposure of radiation, an effect called potentiation. Two different processes of potentially-lethal damage (PLD) repair have been observed. In actively growing hamster V79 cells, the repair of the PLD that can be expressed by hypertonicity treatment is rapid, with a half time of 15 minutes. In confluent mouse cells, the repair time of PLD may be as long as 24 hours. This investigation substantiates a current concept that an apparent single-hit inactivation process cannot exclude the existence of repair processes