What margin do you give around the internal mammary vessels when treating IMN nodes for breast cancer?

I typically use 8mm-1 cm around the vessels, excluding sternum and lung. I contour the vessels in the 1st-3rd intercostal spaces. MA20 used 1 cm around the vessels with coverage by the 80% IDL.

The only exception to this approach is if patients had radiographically enlarged internal mammary nodes. I...