Advanced TP

Choice of optimal beam energy

4MV 6MV 8MV 10MV

≥18MV 15MV

Aspects

Cranial HN

 depth penetration  dose delivered to normal tissue  penumbra broadening

Thorax

Pelvic

Higher energy in low density regions

 higher energies means larger penumbra due to increase in lateral electron transport (≥10MV)  sufficiently accurate planning calculation algorithms are required for decisions on optimal beam energy