Evaluation of time-dose factors in glottic tumors.

Sixty patients with localized squamous cell carcinoma of the vocal cord without nodal or metastatic disease were treated with four fractions per week. No serious complications occurred with the dose and fractionation schedule as outlined. Voice quality after treatment has been satisfactory. After a minimum of two years follow-up the control rates for T1 and T2 tumors are 80% and 81.5%, respectively. All radiation therapy failures were cured surgically. A dose-response curve was constructed for T1 lesions, utilizing the Ellis' formula to derive the NSD, from data from different therapy centers. There appears to be no differences in the parameters studied between four and five fractions per week treatment schedules. A ret dose of approximately 1800 appears somewhat low for optimal control rates in T1 and T2 tumors.