NCS Report 22: Code of practice for the quality assurance and control for intensity modulated radiotherapy

Auditing local methods for quality assurance in radiotherapy using the same set of predefined treatment plans

“…Another limitation is that, for comparison purposes, the audit team defined the evaluation criteria according to national guidelines which may not be exactly the same as the ones used locally. Despite national guidelines [2,3], the evaluation criteria varied slightly among institutes but the impact on the results of this work is negligible. Finally, small differences exist in the implementation of the gamma analysis between QA vendors.…”

“…The 2D measurements from the array and film were compared with the 3D dose distribution from the TPS using a 3D global gamma analysis [23], normalised to the maximum computed dose in the phantom. For the simple and complex IMRT and VMAT plans, the gamma pass rates were calculated using gamma parameters 3 mm and 3% [2,3,23], while for the stereotactic plan these settings were 1 mm and 5% [24]. A dose threshold of 10% of the measured maximum dose and a pass criterion of 95% or higher was used.…”

“…Several reports have been written regarding recommendations on quality assurance (QA) for IMRT and VMAT plans [1][2][3][4][5]. Still, local implementations of plan-specific QA methods may vary because of differences in hardware, software and evaluation metric.…”

Time‐resolved dosimetry using a pinpoint ionization chamber as quality assurance for IMRT and VMAT a)

“…• Implementation of any QA method for the verification of IMRT and VMAT should be carried out in the context of existing guidelines and recommendations in literature. [1][2][3][4][5] As each QA method has some limitations, 5,28,29 it is recommended to first apply multiple QA methods as a safety net at the introduction of a TPS class solution for a specific treatment indication. In addition, it is preferable to use QA methods that allow direct comparison of the results.…”

“…This gives rise to concern about the safety of the dose delivery and it is commonly appreciated that patient-specific pretreatment quality assurance (QA) is required. [1][2][3][4] In particular, during the implementation of the new techniques into the clinic, these QA tests often include ionization chamber point dose measurements. 5 However, usually only the integral dose delivered during a treatment fraction is measured.…”