Clinical usefulness of real-time tissue elastography in the evaluation of cervical lymph node metastases in patients with oral cancer S. Taira, Y. Nikkuni, T. Hayashi, et al.
Jpn J Head Neck Cancer 2008: 34: 518–525 .
The EUB-8500 with the newly-developed “real-time tissue elastography” technology enables the tissue elasticity to be displayed. Real-time tissue elastography may thus be useful for characterizing pathological tissue in cervical lymph node metastases in oral cancer. Therefore, the authors studied its clinical usefulness in diagnosing cervical lymph node metastases in oral cancer using an ultrasound diagnostic system equipped with the real-time tissue elastographic function.
Twenty-six lymph nodes in 15 patients with oral cancer were enrolled in this study. Based on the Tsukuba Elastography Score, the authors classified real-time tissue elastographic images of lymph nodes into five patterns: pattern 1- red, yellow and green areas are equally distributed; pattern 2 – small blue spots are seen in the red, yellow and green areas; pattern 3 – red, yellow, green and blue areas were equally distributed; pattern 4 – red, yellow and green spots were seen in the blue area; and pattern 5 – blue area only. The patterns of images were compared with the histopathological diagnosis obtained from surgery. Metastatic nodes showed patterns 3, 4 or 5, whereas non-metastatic nodes showed pattern l or 2.The differences in tissue elasticity between metastatic nodes and non-metastatic nodes were clearly identified. If the patterns 3, 4 or 5 were assumed as metastases, the precision in diagnosis was as follows: sensitivity of 92%, specificity of 86%, accuracy of 88%, positive predictive value of 85% and negative predictive value of 92%. Additionally, metastatic nodes with a minimum axial diameter of 0.5 cm could be precisely detected using elastography.
These results indicated that real-time tissue elastography is a promising diagnostic modality that allows characterization and differentiation of benign and malignant lymph nodes with a high sensitivity, specificity and accuracy, offering complementary information to conventional ultrasonographic imaging.