Imaging for early stage breast cancer

IGRT with CBCT for prone APBI

343 CBCT verifications at 70 patients in prone position manual matching between planning and CBCTs using breast/chest wall interface

planning CT

CBCT

AP SI ML systematic 0.38 0.21 0.28 random 0.43 0.29 0.37 margin 1.26 0.73 0.96

the interfraction variations detected are comparable

to those reported for APBI with a supine setup

the currently applied margin to the CTV of 1.5 cm

adequately compensates for the detected setup

variability

Derived quantities from shifts in cm

Jozsef et al. IJROBP 81:568-574. 2011