Enhanced sonographic imaging to diagnose lymph node metastasis: importance of blood vessel volume and density
Menée à l'aide d'un modèle murin, cette étude évalue la faisabilité d'une technique à base d'ultrasons de haute fréquence pour détecter des anomalies de volume et de densité des vaisseaux sanguins dans les ganglions lymphatiques et améliorer le diagnostic précoce des métastases ganglionnaires
Lymph node size is an important variable in ultrasound diagnosis of lymph node metastasis. However, the size criterion often leads to oversight of tumor-positive lymph nodes within the range of "normal" size, such that more accurate diagnostic criteria for lymph node metastasis are required. In this study, we show how diagnosis of lymph node metastasis can be improved by evaluating changes in blood vessel volume and density, using a novel contrast-enhanced high-frequency ultrasound (CE-HFUS) system with Sonazoid. An MRL/MpJ-lpr/lpr (MRL/lpr) mouse model of lymph node metastasis was used in which lymph nodes are similar in size to humans. Metastasis via lymphatic vessels to axillary lymph nodes (proper ALNs) was induced by injection of tumor cells into the subiliac lymph nodes. Within 21 days of injection, significant increases in blood vessel volume and density, but no increases in the size of the proper ALNs, were observed. The increase in blood vessel density was confirmed with immunohistochemical analysis, and was positively related to tumor cell proliferation as measured using bioluminescence imaging. Together, our results demonstrated that alterations in blood vessel volume and density precede alterations in lymph node size in the early stages of lymph node metastasis. Detection of these changes by ultrasonography may offer new criteria for early diagnosis of lymph node metastasis.
Cancer Research , résumé, 2013