Head and Neck Squamous Cell Carcinoma: Improving the Detection of Metastatic Cervical Lymph Nodes on a Combined PET/CT Scan

2017-01-09T01:48:15Z (GMT) by Rebecca Sin May Lim
Objective: The presence of cervical lymph node metastasis is an important prognostic factor for patients with head and neck squamous cell carcinomas (HNSCC). Accurate assessment of lymph node metastasis in these patients is essential for appropriate management and for prognostic and management purposes. Here, we evaluated the effectiveness of the maximum standardized uptake value (SUVmax) on positron emission tomography (PET) in assessing lymph node metastasis in head and neck squamous cell carcinomas prior to surgery.   
       Methods: A retrospective review of 74 patients with HNSCC who underwent PET/CT prior to neck dissection were examined. Pre-operative PET/CT scans were reviewed by a single, experienced nuclear medicine physician and SUVmax of the largest node in each nodal basin documented. These were compared with the histology results of the neck dissection.
       Results: A total of 364 nodal basins including 86 basins with metastatic nodes were evaluated. A nodal SUVmax ≥3.16 yielded a sensitivity of 74.4% and specificity of 84.9% in detecting metastatic nodes. The ratio between nodal SUVmax and liver SUVmax was found on receiver operating characteristic (ROC) to be effective in detecting metastatic nodes with an area under ROC curve of 0.90. A nodal SUVmax /Liver SUVmax ratio ≥0.90 yielded a sensitivity of 74.1% and specificity of 93.4%.
       Conclusions: Nodal SUVmax and nodal SUVmax/ liver SUVmax are both useful in the pre-operative detection of metastatic nodes. The latter is likely to be more useful as it corrects for inter-scanner variability.