3514-3515 / 3581
Proton Benefit
• Proton penumbra not steeper than photons
– Dose distribution in high dose region not superior
than photons
– OAR near target with max dose constraint not
spared
• Advantage manifested in intermediate and low
dose levels
• Model based advantage most likely in OAR
with considerable volume effects:
+Lung, Liver, Parotids
- Spinal Cord, Rectum, Brainstem