EORTC radiotherapy group quality assurance: mechanical checks and beam alignments of megavoltage equipment.

In 1987 mechanical checks of megavoltage units and simulators were included in the on-site physics program of the EORTC. The results reported were obtained in 16 different centres and concern 23 accelerators, 14 cobalt units and 14 simulators. In general, the deviations observed for accelerators and simulators are smaller than for cobalt units. A single score, based on the deviations observed for the mechanical checks, is attributed to each centre.