Lymphatic drainage and efficiency of computed tomography in the detection of lymph node metastasis in NO stage patients with squamous cell carcinoma of the mouth and oropharynx

Clinical examination alone is not sufficient to precisely evaluated lymph node involvement in head and neck cancer. The results of computed tomography on the neck and lymphoscintigraphy were evaluated in 21 patients with carcinoma of the mouth and oropharynx staged NO. Nine patients were treated by homolateral and 12 by bilateral neck dissection. Sensitivity and specificity of computed tomography were 16% and 73% for homolateral side and 0% and 90% for contralateral side, respectively. Lymphatic drainage was observed in 76.2% of the cases. No-migration was associated with cases involving the retromollar region and tonsillar fossa, where injection of the 99m Tc-Dextran 500 is more difficult. Bilateral migration occurred only in carcinomas of the floor of the mouth, with involvement of the midline. From these results it was concluded that computed tomography was less efficient than clinical examination. Nevertheless it must be considered that conventional computed tomography was used. We are currently undertaking similar studies with helical computed tomography. Lymphoscintigraphy showed promising results, and the same method to evaluated sentinel lymph nodes in patients with carcinoma of the mouth is being used. (author)