Sentinel Lymph Node Biopsy in Head and Neck Cancer

Preoperative Evaluation and Patient Selection

The European Society of Nuclear Medicine recommends peritumoral injection of 99mTc-labeled colloid with preoperative lymphoscintigraphy to map drainage patterns and identify aberrant pathways, as established by the SENT trial protocol 1, 2
Advanced imaging (CT, MRI, ultrasound-guided FNA, or PET/CT) is necessary to confirm clinical N0 status, as gross lymphatic involvement distorts normal drainage patterns, according to the European Journal of Nuclear Medicine and Molecular Imaging 3, 4
Patients with T1 or T2 tumors, clinically N0 neck, and oral cavity or accessible oropharyngeal subsites are suitable for SLNB, as defined by the SENT trial inclusion criteria 4

A dual detection technique using both blue dye injection and gamma probe guidance is recommended, as it identified 57 of 59 positive nodes vs. 44 of 59 for blue dye alone, according to the SENT trial protocol 1, 4
Multiple sentinel nodes should be harvested, as there may be multiple first-echelon nodes that are not necessarily closest to the primary tumor, as established by the European Journal of Nuclear Medicine and Molecular Imaging 1, 4
Step-serial sectioning at 150-micron intervals with hematoxylin-eosin staining and pan-cytokeratin immunohistochemistry are necessary for pathologic evaluation to detect micrometastases, as recommended by the European Journal of Nuclear Medicine and Molecular Imaging 4

Clinically positive necks (N+), T3/T4 tumors, and hypopharynx and supraglottic larynx primaries are contraindications for SLNB, as established by the SENT trial protocol 4
A clinical decision algorithm for early-stage oral/oropharyngeal SCC with cN0 neck recommends confirming T1/T2 staging, obtaining advanced imaging, and proceeding with SLNB for other oral cavity/accessible oropharynx sites, according to the European Journal of Nuclear Medicine and Molecular Imaging 4

The European Association of Nuclear Medicine recommends sentinel lymph node biopsy (SLNB) for patients with T1-T2 oral/oropharyngeal squamous cell carcinoma and clinically negative necks confirmed by physical examination and imaging, offering accurate nodal staging while avoiding unnecessary neck dissections in approximately 70-75% of patients who ultimately have no nodal disease 5, 6
SLNB should be offered to patients with early-stage tumors (T1/T2 only) and clinically N0 neck confirmed by both physical examination and advanced imaging to exclude occult nodal disease that could distort lymphatic drainage 7, 8

The European Journal of Nuclear Medicine and Molecular Imaging suggests that SLNB is validated for oral cavity tumors (tongue, buccal mucosa, gingiva, hard palate) and accessible oropharyngeal subsites 9, 8
SLNB remains investigational for hypopharynx and supraglottic larynx due to poor access and close proximity of primary tumor to first-echelon nodes 9, 8

SLNB avoids overtreatment in 70-80% of cN0 patients who have no nodal disease, significantly reducing morbidity while maintaining oncologic safety, and minimizes surgical morbidity by avoiding formal neck dissection in node-negative patients 5, 6
The European Association of Nuclear Medicine recommends preoperative lymphoscintigraphy with 99mTc-labeled colloid to map drainage patterns, and a multidisciplinary team including nuclear medicine, surgery, and pathology expertise for optimal results 5, 6

The European Journal of Nuclear Medicine and Molecular Imaging suggests that essential components for optimal results include preoperative lymphoscintigraphy, intraoperative detection using both blue dye injection and gamma probe guidance, specialized pathologic examination, and a multidisciplinary team 5, 6