The tumor bed: very important for PBI !
•
Surgical clips guide tumor
bed delineation on CT
•
Integrate MRI or US in
addition to CT/surgical
clips.
•
The expansion of CTV to
PTV varies (0.5– 1.5 cm).
•
Tumor is often eccentric
in a lumpectomy
specimen: optimal
margin?
•
The seroma could also
induce errors!