A dedicated information system comprising computers and software intended to reduce human error by monitoring linear accelerator parameters to verify that the proper radiotherapy treatment is being delivered, and to provide a permanent record. It permits a computer verification of all treatment parameters prior to the commencement of a patient's treatment. Patient information, treatment machine parameters and the dose prescription relating to that patient's treatment are entered into a patient file and stored. Comparisons are made by the record and verify system and system interlocks to ensure that treatment is not permitted if any parameters are outside the predetermined tolerances.