The objective of this study was to investigate the effect of field output factors (FOFs) according to the current protocol for small‐field dosimetry in conjunction to treatment planning system (TPS) commissioning. The calculated monitor unit (MU) for intensity‐modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans in Eclipse™ TPS were observed. Micro ion chamber (0.01 CC) (CC01), photon field diode (shielded diode) (PFD), and electron field diode (unshielded diode) (EFD) were used to measure percentage depth doses, beam profiles, and FOFs from 1 × 1 cm² to 10 × 10 cm² field sizes of 6 MV photon beams. CC01 illustrated the highest percentage depth doses at 10 cm depth while EFD exhibited the lowest with the difference of 1.6% at 1 × 1 cm². CC01 also produced slightly broader penumbra, the difference with other detectors was within 1 mm. For uncorrected FOF of three detectors, the maximum percent standard deviation (%SD) was 5.4% at 1 × 1 cm² field size. When the correction factors were applied, this value dropped to 2.7%. For the calculated MU in symmetric field sizes, beam commissioning group from uncorrected FOF demonstrated maximum %SD of 6.0% at 1 × 1 cm² field size. This value decreased to 2.2% when the corrected FOF was integrated. For the calculated MU in IMRT‐SRS plans, the impact of corrected FOF reduced the maximum %SD from 6.0% to 2.5% in planning target volume (PTV) less than 0.5 cm³. Beam commissioning using corrected FOF also decreased %SD for VMAT‐SRS plans, although it was less pronounced in comparison to other treatment planning techniques, since the %SD remained less than 2%. The use of FOFs based on IAEA/AAPM TRS 483 has been proven in this research to reduce the discrepancy of calculated MU among three beam commissioning datasets in Eclipse™ TPS. The dose measurement of both symmetric field and clinical cases comparing to the calculation illustrated the dependence of the types of detector commissioning and the algorithm of the treatment planning for small field size.

中文翻译：

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在eclipse™治疗计划系统中，基于IAEA / AAPM行为准则的校正后的现场输出因子对小现场剂量的影响对计算出的监测器单元的影响。

这项研究的目的是结合治疗计划系统（TPS）的调试，根据当前的小剂量剂量学协议，调查磁场输出因子（FOF）的影响。在Eclipse™TPS中观察了计算出的用于强度调制放射治疗（IMRT）和体积调制电弧治疗（VMAT）计划的监测器单元（MU）。使用微离子室（0.01 CC）（CC01），光子场二极管（屏蔽二极管）（PFD）和电子场二极管（非屏蔽二极管）（EFD）测量1×1范围内的深度剂量百分比，束轮廓和FOF 6 MV光子束的cm ²至10×10 cm ²场大小。CC01说明了在10 cm深度处最高的深度剂量百分比，而EFD则显示了最低百分比，在1×1 cm ²处相差1.6％。CC01还产生了稍宽的半影，与其他探测器的差在1毫米之内。对于三个检测器的未校正FOF，在1×1 cm ^2的场尺寸下，最大百分比标准偏差（％SD）为5.4％。当应用校正因子时，该值下降到2.7％。对于以对称场尺寸计算的MU，未经校正的FOF的光束调试组在1×1 cm ²场尺寸下显示出最大％SD为6.0％。当整合校正后的FOF时，该值降低到2.2％。对于IMRT-SRS计划中计算出的MU，校正后的FOF的影响将计划目标体积（PTV）中小于0.5 cm ³的最大％SD从6.0％降低到2.5％。对于VMAT-SRS计划，使用校正后的FOF进行光束调试也降低了％SD，尽管与其他治疗计划技术相比，它的影响不大，因为％SD仍低于2％。在这项研究中，已证明使用基于IAEA / AAPM TRS 483的FOF可以减少Eclipse™TPS中三个光束调试数据集中计算出的MU差异。对称场和临床病例的剂量测量结果与计算结果进行了比较，说明了探测器调试类型和小场尺寸治疗计划算法的依赖性。