What must the constancy of linac output be compared to when checked daily?

The constancy of linear accelerator (linac) output should be compared to benchmark values established during commissioning due to their critical role in ensuring consistent and accurate radiation delivery. These benchmark values are determined during the initial setup and configuration of the linac, representing the expected performance characteristics under specified conditions. Regular comparison to these established benchmarks allows for the detection of any deviations in output, which could indicate potential issues with the equipment or changes in its performance over time.

Maintaining daily checks against these benchmarks helps ensure that any necessary adjustments or repairs can be made promptly, thereby safeguarding the quality of patient care. This practice is fundamental in the field of medical dosimetry, where precision in dosimetry calculations is vital for effective treatment.

While patient treatment records, manufacturer's guidelines, and daily operational logs provide valuable information, they do not serve as reliable references for assessing output constancy in the same way as benchmark values. Each of these elements plays a role in the overall workflow and quality assurance processes but does not specifically focus on the output consistency of the linac.