The Level I mail out audit is an independent measurement of linac output under reference conditions. Optically Stimulated Luminescent Dosimeters (OSLDs) are sent to a facility, irradiated, and returned to the ACDS for analysis. All clinical photon and electron beams are included in the audit. The current subscription provides a Level I audit for each facility every two years. The ACDS Level I audit is mutually recognised for equivalence to the Imaging and Radiation Oncology Core (IROC) OSLD audit.
Figure 1: The OSLD audit kit.