Elective neck irradiation on ipsilateral side in patients with early tongue cancer for high-risk group with late cervical lymph node metastasis.

A prospective study was performed to assess the efficacy of elective neck irradiation (ENI) on the ipsilateral side in patients with early tongue cancer among a high-risk group with late cervical lymph node metastasis. Patients in the high-risk group had T2-tumors, excluding superficials or T1-tumors > or =19 mm in maximal diameter with invasion or ulcer. Between February 1989 and October 1997, 70 patients with tongue cancer of Stages I and II were enrolled in the present study (ENI group: 31, non-ENI group: 39). In a combination therapy of external beam irradiation and brachytherapy, the standard dose of interstitial brachytherapy for primary tumors was approximately 60 Gy. Irradiation was initiated with a 9-MeV electron beam at a dose of 50 Gy on the ipsilateral side of the neck only when the day of brachytherapy approached. Three patients (9.7%) in the ENI group had neck lymph node metastasis as did 5 (12.8%) in the non-ENI group (p= 0.684). In patients with ulceration, the incidence of subsequent lymph node metastasis was significantly higher (p=0.029). Neck lymph node metastasis occurred in 2 (16.7%) of 12 patients with ulcers in the ENI group and in 2 (66.7%) of 3 with ulcers in the non-ENI group. Although we could not demonstrate the significant efficacy of ENI in the high-risk group in this study, ENI decreased the neck lymph node metastasis. In addition, our results suggested that ENI particularly inhibits cervical lymph node metastasis in tongue tumor patients with ulcers.