The Study Of Dextran-DTPA-Gd For Sentinel Lymph Node Of Rabbit VX2 Tongue Carcinoma With Interstitial Mmagnetic Resonance Lymphography

PURPOSE: To evaluate the feasibility of the interstitial magnetic resonance lymphography(IMRLG)by using Dextran-DTPA-Gd for studying sentinel lymph node( SLN) and detecting the cervical lymph node metastasis in rabbit VX2 tongue cancer.METHODS: VX2 tumor tissues were transplanted to the left ventral s ubmucosa of the tongue of 16 healthy New Zealand rabbits. After 21 days transplantation, 0.2ml Dextran-DTPA-Gd was injected into the bila teral submucosa of the tongue,then the MR images by using 3D enha ncement magnetic resonance lymphography at 15,30,45,60 mins and 4,24 hs after injection were obtained. The signal intensities after enhancing were measured to calculate the enhancing rates(E%) of lymph nodes at same time. The further evidences were provided for positioning SL N, observing the lymphatic drainage lines and the density and morphol ogy of the neck and the cervical lymph nodes. The Methylene blue w as injected into the same areas of tongue after 24 hours IMRLG,and t hen the dissection and histopathological examination of Methylene blue-labeled SLNs were performed. SPSS19.0 software package was used f or statistical analysis.RESULTS: 14 rabbits were successfully transplanted VX2 tumor tissue s(14/16) and 12 rabbits were detected with lymphatic metastasis. The d ifferences of enhancing rates between the metastatic lymph nodes and t he normal nodes was obvious in each rabbit at the same time(P<0.05).15 lymph nodes were diagnosed as the metastatic lymph nodes by IM RLG in 30 lymph nodes of the 12 rabbits, while the 13/15 metastatic lymph nodes were affirmed by pathological diagnosis without significan t difference(P>0.05). The SLN can be positioned readily by IMRL G and Methylenc blue, which results obtained have a good consistency.CONCLUSIONS: Dextran-DTPA-Gd could effectively position the cerv ical lymph node and was feasible in localization of the SLNs of tongu e carcinoma metastasis. It also provide brief evidence in diagnosing the status of the regional lymph node metastasis.