OC-020 Sentinel lymph node biopsy for early stage oral cancer; experience of 3 Dutch Head and Neck centers. (March 2019) - Den Toom, I.; Boeve, K.; Van Es, R.; De Keizer, B.; Van Weert, S.; Willems, S.; Witjes, M.; Bloemena, E.; Leemans, R.; De Bree, R.