<qa>  What was the purpose of the study?The aim of our study was to evaluate the value of two different altered fractionation schedules hyperfractionation and accelerated fractionation with concomitant boost in comparison with conventional fractionation in primary definitive radiotherapy for squamous cell carcinomas of the larynx, oropharynx or hypopharynx. The study began and was conducted while the only teletherapy unit in our department was the cobalt-60 machine. During that period we were expecting the installation of new sophisticated equipment. We assumed that the results of this study would be also able to show whether or not it would be rational to use the altered fractionation regimens on the new machines. 