What is the tolerance for daily check of linac output constancy?

The tolerance for daily checks of linear accelerator (linac) output constancy is indeed 3%. This percentage ensures that the output of the linac remains consistent and within acceptable limits on a daily basis, which is vital for delivering precise doses to patients in radiation therapy. Maintaining this level of accuracy is critical for the safety and effectiveness of treatment, as variations outside of this range could lead to underdosing or overdosing patients, impacting treatment outcomes.

Regular checks of this magnitude support quality assurance protocols, enabling the detection of any potential drift or malfunction in the linac's performance. The 3% tolerance provides a balance between allowing for minor fluctuations due to environmental factors or equipment wear and ensuring that any significant issues are addressed promptly to maintain treatment integrity.

In contrast, other percentages such as 1%, 2%, or 5% do not reflect the standard practice for daily checks of output constancy in radiation therapy, where a tighter tolerance of 1% may be applied for more critical situations or equipment, while 5% is generally considered too lenient for daily outputs, failing to adequately safeguard patient treatment accuracy.