OP133: Tongue carcinoma: Were lympha goes? A one center study on lymphatic mapping

Purpose Neck treatment in cN0 tongue squamous cells carcinoma is still debated. Sentinel node (SN) technique could help the decision making, but is still unclear which kind of neck dissection must be performed in SN+ cases. Moreover, the pattern of cervical metastases has wide intra-individual variation and up to 5% of nodal metastases are found to be contralateral. In 2006 we published the lymphatic mapping study on 14 N0 patients affected by advanced tongue cancer. Contralateral drainage occurred in 11 patients and in two of them metastatic nodes were found on the contralateral side only. Metastases were found only in radioactive lymph nodes. The limits of this technique were the need of lymphoscintigraphy of specimens as to compare preoperative and postoperative imaging and the impossibility to visualize the lymphatic ways during surgery. Our purpose is to overcome these limits comparing lymphoscintigraphy with Tc-99 and near-infrared fluorescence imaging using indocyanine green die. Material and methods The study population will include 14 patients with cT4 cN0 M0 SCCs. The lymphatic drain of each patient is studied 12 h before surgery with a static scintigraphy and then with intraoperative injection of indocyanine green. Neck dissection is performed in two steps: first is performed a green indocyanine guided lymphatic dissection checked by a radioactive probe that are send separately for histopathological examination and then completion of bilateral neck dissection and en-block tumor resection. Results We expect to find that the scintigraphic positive lymph nodes are the same identified by the green indocyanine, and that the metastases are found only in the guided dissection specimens. Conclusion This study could provide a reliable tool to intraoperatively visualize the lymphatic draining of tongue tumor in order to achieve tailored patient treatment, identifying and removing the only and real lymphatic ways at risk to be involved by metastases.