The Role of Sentinel Node Lymphoscintigraphy in Identifying Patterns of Internal Mammary Node Drainage in Breast Cancer

Li Liu, MD
OncoLink Assistant Editor
Last Modified: October 25, 2000

Presenter: M. C. Smitt
Affiliation: Stanford University, Stanford, CA


Postmastectomy radiation therapy has recently been shown in randomized studies to improve overall survival for patients with node-positive breast cancer. It remains controversial whether or not to treat internal mammary node (IMN). Both Danish and Canadian studies of postmastectomy radiation therapy included IMN. In this study, the researchers from Stanford University examined whether sentinel node lymphoscintigraphy would help to identify patterns of IMN drainage.

Materials and Methods:

  • Lymphoscintigraphy was performed using four peritumoral injections of 1 mL technetium sulfur colloid.

  • 155 women underwent lymphoscintigraphy during 1997 and 1998.


  • 25 women (16%) demonstrated IMN drainage, with or without associated axillary sentinel node.

  • 8 patients had only IMN drainage.

  • The total number of IMN nodes identified was 30. Of them, 18 (60%) were in the 'lower' IMN region.

Authors' Conclusions

  • Sentinel node lymphoscintigraphy may identify patterns of IMN drainage.

  • Over half of all IMN sentinel nodes were located in the lower IMN region.
Clinical/Scientific Implications:
  • Understanding of the patterns of IMN drainage has potential implications for radiation planning.

  • Pathological correlation with sentinel node lymphoscintigraphy findings is critical and should be studied.