The recent publication of the new code of practice IAEA/AAPM TRS-483 introduces output correction factors to correct detector response changes in relative dosimetry of small photon beams. In TRS-483, average correction factors are reported for several detectors in high-energy photon beams at 6 and 10 MV with and without flattening filter. These correction factors were determined by Monte Carlo simulation or experimental measurements using several linacs of different brands and vendors. The goal of this work was to validate the output correction factors reported in TRS-483 for 6 MV photon beams of a TrueBeam STx® linac. The validation was performed using Monte Carlo simulations of four radiation detectors employed in the dosimetry of small photon beams and whose output correction factors were determined using a different radiation source than TrueBeam STx®. The results show that Monte Carlo calculated output correction factors, and those reported in the code of practice TRS-483 fully agree within $\sim$1%. The use of generic correction factors for a TrueBeam STx® and the detectors studied in this work is suitable for small field dosimetry static beams within the uncertainties of Monte Carlo calculations and output correction factors reported in TRS-483.

IAEA / AAPM TRS-483新实践准则的最新发布引入了输出校正因子，以校正小光子束相对剂量测定中检测器响应的变化。在TRS-483中，报告了使用和不使用滤光片时在6和10 MV下高能光子束中几个探测器的平均校正因子。这些校正因子是通过蒙特卡罗模拟或使用不同品牌和供应商的几种直线加速器进行的实验测量确定的。这项工作的目标是验证TrueBeam STx直线加速器的6 MV光子束在TRS-483中报告的输出校正因子。验证是使用小光子束剂量学中使用的四个辐射探测器的蒙特卡洛模拟进行的，其输出校正因子是使用与TrueBeamSTx®不同的辐射源确定的。结果表明，蒙特卡洛计算了输出校正因子，而实践准则TRS-483中报告的校正因子完全符合$〜$1％。TrueBeamSTx®和本研究中使用的检测器的通用校正因子的使用适合在蒙特卡洛计算和TRS-483中报告的输出校正因子不确定性范围内的小剂量剂量静态束。