What is the acceptable range for x-ray beam flatness?

The acceptable range for x-ray beam flatness being 3% indicates that the variation in beam intensity across the treatment area should not exceed this percentage. Beam flatness is critically important in medical dosimetry because uniformity of the radiation dose is essential for effective treatment and minimizing damage to surrounding healthy tissues.

A flatness deviation greater than 3% could lead to areas within the treatment field receiving insufficient radiation to achieve effective tumor control, while other areas may receive excessive radiation, increasing the risk of side effects. Maintaining beam flatness within this range ensures a consistent dose distribution, which is vital for the safety and efficacy of radiation therapy.

In practice, adherence to the 3% standard aligns with common clinical protocols and guidelines established by various professional organizations, highlighting its importance in the routine calibration and quality assurance of radiation therapy equipment.