Analysis of time-dose factors in clinically positive neck nodes treated with irradiation alone in squamous cell carcinoma of the head and neck.

This is a retrospective analysis of time-dose factors in 139 patients with 238 evaluable clinically positive lymph nodes treated with external beam radiation therapy alone to the primary lesion and neck for squamous cell carcinoma of the head and neck at the University of Florida from October 1964 through April 1980. Lymph node control by lymph node size was 8/8 (100%) for less than 1.0 cm, 51/62 (82%) for 1.0 cm, 68/82 (83%) for 1.5-2.0 cm, 24/40 (60%) for 2.5-3.0 cm, 24/38 (63%) for 3.5-6.0 cm, and 0/8 (0%) for greater than or equal to 7.0 cm. Lymph node control was also influenced by dose, overall treatment time, and fractionation schedule; these factors were interrelated and appeared to increase in importance as the size of the lymph node increased.