Physics Bucharest 2017

OFF-AXIS RATIOS

OAR OAR OAR  

x

y

• Multiply orthogonal factors • Interpolate – Between depths – Between field sizes • Radial non-flatness is over-accentuated – Non-flatness due to • Scatter • Deliberate effect to compensate for beam softening at depth • Apply radial correction

ESTRO physics course, June 2017