Gamma probe accuracy in detecting the sentinel lymph node in clinically N0 squamous cell carcinoma of the head and neck.

The sentinel node, which is not always located at the first-echelon nodal area close to the primary tumor, is the initial recipient of possible metastasis. In order to verify the usefulness of the sentinel lymph node technique in the staging of head and neck cancers, we studied 31 untreated patients with squamous cell carcinoma of the upper airways by injecting them around the primary tumor with technetium 99m albumin microcolloid (99mTc) and submitting them to selective neck dissection with en bloc tumor removal. The nodes were examined after gamma-probe identification of the sentinel node(s). No patients were found to have microscopic tumor spread outside the level(s) containing the gamma-probe-identified sentinel node(s). In only 1 case was the metastatic node not the gamma-probe-positive one, but an adjacent one. Lymphoscintigraphy with 99mTc seems reliable in identifying the sentinel node(s) and might contribute to the reduction of surgical morbidity by reserving therapeutic neck dissection for cases with histologically confirmed nodal metastasis.