Imaging for early stage breast cancer

IORT – intracavitary devices (Intrabeam, Xoft)

central source position – far from target

spherical target volume only

no geographical miss

symmetric margin – target is conformed to spherical applicator, but no imaging

4.5 cm

large dose inhomogeneity within target (68%/1 cm)

large dose gradient at target edge (58%/1 cm)

no dose modulation potential – skin retraction and tungsten-filled sheets for shielding

Xiao et al. Int J Med Phys 4:184-195. 2015