Regarding the different protocols used for external cancer radiotherapy (X or. rays, electron, proton or ions beams) or radioimmunotherapy (Auger electron emitting radionuclides), the initial energy deposited in integrated biological systems (biomolecular and sub-cellular targets) represents a decisive parameter for the primary and more delayed radiation damage. A short-range energy distribution governs mainly (i)) the early survival probability of secondary electrons, (ii)) the spatio-temporal distribution of short-lived reactive radicals inside nascent tracks, (iii)) the primary biomolecular alterations triggered by low energy secondary electrons. The thorough understanding of these fundamental processes requires a real-time investigation of primary radiation events, typically in the temporal range 10(-14) - 10(-11) s. Laser-plasma accelerators based High Energy Radiation Femtochemistry (HERF) represents a newly emerging interdisciplinary field which can be driven in strong synergy with the generation of ultrashort particle beams in the MeV energy domain. The innovating developments of HERF would favour the investigation of prethermal radiation processes in aqueous and biochemically relevant environments. In this way, the quantum character of a very-short lived low-energy electron state (p-like configuration) represents a promising sub-nanometric probe to explore early radiation processes in native tracks. The specific properties of ultra-short electron beams accelerated by TW laser are very useful for future developments of spatio-temporal radiation biophysics in complex biological systems such as living cells.