Initial CT findings in early tongue and oral floor cancer as predictors of late neck metastasis.

Detecting the risk factors for late neck metastasis (LNM) in early tongue and oral floor cancer is important for establishing an accurate prognosis, as well as for increasing survival rates. Patients with either stage I or II tongue and oral floor cancer underwent either a resection of the primary tumor or interstitial radiotherapy without neck dissection. We measured the short- and long-axis diameters of lymph nodes on initial CT images. Of the 38 patients, 20 had LNM and 18 did not. CT images showed a total of 161 lymph nodes. Twenty-five "occult lymph nodes" developed into LNM, whereas the remaining 136 "reactive lymph nodes" did not. Comparison between "occult" and "reactive" lymph nodes revealed significant differences in the short-axis diameters (p=0.01). The measure of short-axis diameters of neck lymph nodes on initial CT images is a useful predictor of LNM in patients with early tongue and oral floor cancer.