ESTRO PT 2018

Effect of Ionizing Radiation on Biomolecules

Indirect effects: Interaction of photons or electrons with water molecules Result: Formation of reactive oxygen species (ROS)

Radiolysis of water !

hν

O + + e -

H 2 O H 2

Hydroxyl radical: H 2

O + + OH -

O+ H

2 O H 3

Solvated electrons: e - + [H 2

0 + ] e -

aqu.

Hydroxyl radical: e -

2 O OH -

+ H

aqu.

Hydrogen peroxide:

OH - + OH -

H

O

2

2