Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

C. CHAMPION; M. A. QUINTO; J. M. MONTI; M. E. GALASSI; P. F. WECK; O. A. FOJÓN; J. HANSSEN; R. D. RIVAROLA

PHYSICS IN MEDICINE AND BIOLOGY

IOP PUBLISHING LTD

Lugar: Londres; Año: 2015 vol. 60 p. 7805 - 7828

0031-9155

Water is a common surrogate of DNA for modelling the charged particleinduced ionizing processes in living tissue exposed to radiations. The present study aims at scrutinizing the validity of this approximation and then revealing new insights into proton-induced energy transfers by acomparative analysis between water and realistic biological medium. In this context, a self-consistent quantum mechanical modelling of the ionization and electron capture processes is reported within the continuum distorted wave-eikonal initial state framework for both isolated water molecules and DNA components impacted by proton beams. Their respective probabilityof occurrence?expressed in terms of total cross sections?as well as their energetic signature (potential and kinetic) are assessed in order to clearly emphasize the differences existing between realistic building blocks of living matter and the controverted water-medium surrogate. Consequences in radiobiology and radiotherapy will be discussed in particular in view oftreatment planning refinement aiming at better radiotherapy strategies.