A sentinel node is the first lymph node the cancer cells metastasize to. At the biopsy, the sentinel node is resected and examined for pathology. If lymph node metastases are not deceted by light microscopy, an immunohistochemistry is perfomed to exclude sub- micrometastases. If there is no metastasis, the surgeon will limit the operation as if there is not tumor spreading (N0).
Dynamic sentinel node staging
In dynamic sentinel node staging, radioactive istopes are injected into the base of the primary tumor. The isotopes are then transported in the lymphatic system from the tumor to the first lymph node where they gather. This lymph node is identified with a gamma camera and peroperatively with a gamma detector. The sentinel node can be resected via a small incision.
The benefit of dynamic sentinel node staging is that the morbidity is low for the operative procedure. It is assumed that the sensibility and specificity is also higher than in anatomical sentinel node staging.
A close cooperation between the department of nuclear medicine and the surgeon is neccessary.
- Examine for lymph node metastasis.