Radiation Therapy?

I had a 4 cm tumor removed with my breast.  My pathology report showed that there was "vascular/lymphatic invasion", but my sentinel node biopsy (which removed 7 nodes) did not show any node involvement. I have done 4 treatments of A/C and am doing 4 treatments of taxol.  My question is, would I also benefit from radiation therapy and if not, why not?  My surgeon did not have an opinion.  She just gave me several radiation oncologists to consult with.  My chemo oncologist said there wasn't anything left to radiate.
Thanks.

[CCF-RN,MSN-rf]

Dear quinny:  I am assuming that you have had a mastectomy.  In the case of mastectomy, there are cases in which radiation is recommended but these are usually very aggressive cancers that may have close margins, lymph node involvement, or some other "high risk" reason.  In most cases, it is belived that mastectomy + chemotherapy is adequate, although there is some controversy.  As a point of discussion, you could meet with the radiologist to discuss benefits vs. risks.  Since all therapy has some risk, there needs to be good reason to proceed with additional therapy.