Detection of cervical lymph node metastases in nasopharyngeal carcinomas: comparison with technetium-99m tetrofosmin single photon emission computed tomography and with magnetic resonance imaging.

To compare the effectiveness of techentium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) of the head and neck in evaluating cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC). Forty patients of biopsy-proven NPC with cervical LN metastases underwent head and neck Tc-99m TF SPECT and MRI to detect cervical LN metastases. Agreement positive results of Tc-99m TF SPECT and MRI could correctly detect all of the remaining 22 metastatic LN lesions. For 18 LN lesions with discordant results between Tc-99m TF SPECT and MRI, Tc-99m TF SPECT could correctly detect 1 metastatic and 10 benign LN lesions, while MRI could correctly detect 5 metastatic and 2 benign LN lesions. Tc-99m TF SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with MRI. The combined use of Tc-99m TF SPECT and MRI could significantly increase the accuracy compared with the single use of either Tc-99m TF SPECT or MRI to detect cervical LN metastases in NPC.