Dear whizmedico: There is no non-invasive way to determine definitively if internal mammary nodes are involved with cancer. A CAT scan of the chest may or may not demonstrate enlarged internal mammary lymph nodes. Randomized trials have shown that involved internal mammary nodes (IMN) have a similar prognostic value to axillary nodes, yet there was no survival benefit to extending mastectomy to include dissection of these nodes. Further, radiation to the IMN’s have been associated with increased cardiotoxicity. Therefore, even in cases where there is known IMN involvement, risk benefit ratios must be considered when contemplating therapy.
Thank you for clearing my doubts.