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Purpose:The aim of this study was to create AAPM TG119 benchmark plans for Helical Tomotherapy(HT)commissioning and generate a local confidence limit for HT treatment technique.Methods:Similar as the TG119 report,two preliminary tests were developed to assess the reliability of the HT dose delivery.The first preliminary test is to treat a simple cylindrical target to calibrate the rotational output as described in TG148.The second preliminary test contains five targets,one located at the center of rotation and four off-axis targets,with target doses from 40 to 200 cGy for testing the on-axis and off-axis delivery accuracy.For the complex clinic mock tests,one HT IMRT plan was generated for each of the five IMRT cases described in TG119.Dose prescription and planning objectives were set according to the TG 119 goals.All plans were delivered to a cylindrical water-equivalent phantom.For each plan,the point dose measurements were done using an ion chamber at high and low dose region and the dose distributions were measured in the coronal and sagittal planes using EBT3 film.All data were analyzed following the TG119 reports to generate the confidence limit values.Results:The resulting HT plans show significantly more homogeneous target dose and greater sparing of critical structures when compared to TG119 results.Ion chamber results showed average differences between measured and calculated point doses of-0.09%±0.57%at high dose region and 0.24%±0.72%at low dose region with corresponding confidence limit of 1.21%and 1.66%,respectively.The gamma passing rate averaged over all mock tests for film measurements was 90.91 ± 3.82%at 2 mm/2%,96.96 ± 1.85%at 3 mm/3%and 99.20 ± 0.65%at 4 mm/4%,leading to the confidence limit of 83.4%,93.3%and 97.9%,respectively.Conclusion:In spite of the differences in the preliminary tests and the phantom for measurements,our confidence limit values are well within the TG119 baseline values,which proves that we has commissioned HT treatment technique with adequate accuracy.