The gamma probe is used to detect the highest gamma counts transcutaneously in the area of expected lymphatic drainage (this may be multiple basins). The area between the primary tumor and expected drainage areas should be examined for high gamma counts as well to evaluate for in-transit disease.
The node(s) with the highest gamma count should be removed.
Any additional node(s) that have gamma counts that are at least 10% of the highest gamma count should be removed.
Any grossly positive or firm lymph node should be removed, given the clinical suspicion for metastatic disease.
Any in-transit nodes should also be identified and excised.
For cervical lymph node biopsies, a small cervical incision is made directly over the area of highest gamma activity in the neck.
For axillary lymph node biopsies, a small incision is made directly over the area of highest gamma activity in the axilla. This is generally a transverse curvilinear incision 1 to 2 cm below the axillary hair line.
For inguinal lymph node biopsies, a small transverse incision is made along the area of highest gamma activity in the groin.
Educational aid only. Verify every dose, indication, and guideline against current institutional protocol. This is not a substitute for clinical judgment.
