2017_IGRT course book

Limitation of MV imaging for set-up

• EPID field images (i.e. not orthgonal) underestimate bony set-up errors by 20% to 50%

• Difference probably insignificant for tangential whole breast irradiation

• Loco-regional treatment or more advanced techniques (SIB? IMRT?) could benefit from a more accurate set up.

EPID kV CBCT

Topolnjak IJROBP 2010