Results of a multicentre dosimetry audit using a respiratory phantom within the EORTC LungTech trial

Evaluation of a new radiochromic film dosimeter, Gafchomic EBT4, for VMAT, SABR and HDR treatment delivery verification

“…The film verification of a typical SABR lung treatment showed agreement between TPS-planned and filmmeasured dose distributions using gamma criteria of 3% (global), 2 mm, with a mean passing rate over three film lots of 99.9% for EBT4 and 95.2% passing rate for EBT3, in simultaneous irradiation conditions. The latter compares well to published data of mean passing rates of the EORTC lungTech trial for a static lung SABR target of 92.0% and 96.0% for a smaller and larger target diameter, at 3%, 3 mm criteria using EBT3 (Lambrecht et al 2019). Similarly, for the IMRT prostate plan, EBT4 showed an improved mean gamma agreement passing rate of 100.0% at 3% (global), 3 mm criteria compared to a passing rate of 97.9% for EBT3.…”

Early results of a remote dosimetry audit program for lung stereotactic body radiation therapy

“…The lung phantom used in this study was similar to the popular CIRS thorax phantom used in other studies [15] , [17] , [18] , [19] . It is also an anthropomorphic phantom containing many heterogeneous regions.…”

“…For SBRT it is recommended that the measurements should be performed in phantoms including low-density lung material and heterogeneous regions to simulate the same physical radiation interactions that occur when treating actual patients. Several SBRT dosimetry audits and phantom studies have been already reported [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] .…”

“…Motion management was possible on this phantom by placing it on a moving platform. Other auditing networks for SBRT [15] , [17] , [18] , [19] used different anthropomorphic phantoms allowing heterogeneous inserts for the target and organs at risk (OAR).…”

Adoption of respiratory motion management in radiation therapy

“…Audit procedures are also frequently used for clinical trial credentialing, to ensure participating facilities are achieving a uniform minimum standard of treatment quality [19] , [20] , [21] , [22] , [23] . Dosimetry audits and clinical trial QA procedures involving simulated respiratory motion have shown worsened measurement outcomes with respect to their static equivalents [24] , [25] , [26] . While patterns of failure have been hypothesised to be related to the motion of the targets, rates of failure were not necessarily improved by the use of MM techniques, and no direct causes were established [24] , [25] .…”