Lymphoscintigraphic details of sentinel lymph node detection in 82 patients with squamous cell carcinoma of the oral cavity and oropharynx

Lymphoscintigraphy for sentinel node (SN) detection has been studied extensively in melanoma and breast cancer. In head and neck squamous cell carcinoma (HNSCC), however, experience in this field is relatively meagre. The purpose of this study was to document and evaluate lymphoscintigraphic findings in HNSCC patients. Eighty-two patients with clinical T1-T4 NO SCC of the oral cavity or oropharynx received peritumoral injections of 25-75 MBq 99m Tc-colloidal albumin (CA). Dynamic lymphoscintigraphy was performed in lateral projection for 20 min, followed by 2 min static imaging in anterior projection. In 26 patients, additional static images were obtained 2-6 h after injection of the tracer. In four of 82 patients, both early and late imaging revealed no tracer transport. In 78 of 82 patients, one (60), two (14) or three (4) SNs could be visualized, either by dynamic scintigraphy (73) or delayed static imaging (5). In 48 of 78 (62%) patients, the SN was visualized within the first minute of dynamic imaging. In particular, SNs of tumours of the mobile tongue were visualized within the first minute. No effect of T-stage or 99m Tc-CA dose on the transport time of the tracer towards the SN was seen. The distribution of the SNs in the various levels of the neck relative to the primary tumour sites within the oral cavity was in concordance with the patterns of lymph node metastases reported traditionally for patients with SCC in the oral cavity. This study demonstrates the different variables affecting SN identification with lymphoscintigraphy using 99m Tc-CA in HNSCC patients.