Determination of machine‐specific tolerances using statistical process control analysis of long‐term uniform scanning proton machine QA results

Abstract

The 3σ of the dose output, flatness, and symmetry differences in all four rooms were comparable to the TG224 tolerance (±2%). For the uniform scanning system, if the measured range is compared against the requested range, it may not always be possible to achieve the range difference within ±1 mm (TG224) for all the ranges.