When evaluating margin status to consider APBI for early stage invasive breast cancer, given the specification for at least 2 mm margins, do you look at the DCIS margin or only the invasive margin?
Additionally, when evaluating margin status for APBI IMRT 30 Gy in 5 fractions which specifies at least 5 mm margins, do you look at the DCIS margin or only the invasive margin?