About Bragg peak effect of protons all are true except:
Ref. Grainger and Allison's Diagnostic Radiology. Page. 30
 
Bragg Peak

The Bragg peak is a pronounced peak on the Bragg curve which plots the energy loss of ionizing radiation during its travel through matter.
For protons, α-rays, and other ion rays, the peak occurs immediately before the particles come to rest
Electromagnetic radiation
Produce ionization in biological system
The dose of a single beam is two to four times greater than the path dose
Beam therapy for AV malformation of the brain