Physics Bucharest 2017

Flattening Filter

Wang Y, JACMP2012

In the FF

• Photons are absorbed → reduced efficiency • Photons are scattered (head scatter 3-10% of photon fluence) → increased contamination radiation • Neutrons are produced (high MV) → increased contamination radiation

Flat profile

Only flat at one depth

• •

Patients and tumors aren’t flat