Compare the Dosimetric Performance of AAA and Axb In Eclipse v18.1
Abstract
Purpose
To compare the dosimetric performance of the Anisotropic Analytical Algorithm (AAA) and Acuros XB (AXB) in IMRT plans recommended by the TG-119 protocol.
Methods
Test plans were generated following the TG-119 IMRT Commissioning Tests Instructions for Planning, Measurement, and Analysis. Each plan was calculated in Eclipse v18.1 using AAA and AXB with identical monitor units. Measurements were performed using a Delta4 phantom with 6X and 10X beams on a Novalis Tx linear accelerator, and with 6X FFF and 10X FFF beams on a TrueBeam STx linear accelerator. Dosimetric analysis was carried out using gamma evaluation (global and local) with criteria of 3%/2 mm, 3%/1 mm, and 2%/1 mm.
Results
Both algorithms demonstrated comparable dosimetric performance. Under the 3%/2 mm gamma criterion, passing rates exceeded 95% for both global and local analyses, except for two local gamma evaluations (10X with AXB and 6X FFF with AAA). Similarly, for the 3%/1 mm criterion, only the 6X FFF measurement with AAA fell below 95%. When applying the more stringent 2%/1 mm criterion, three passing rates below 90% were observed with AAA compared to a single case with AXB.
Conclusion
AAA and Acuros XB demonstrated comparable dosimetric performance for IMRT plans recommended by the TG-119 protocol. Both algorithms achieved gamma passing rates consistent with accepted clinical standards. Differences observed under more stringent gamma criteria did not compromise the dosimetric quality of the plans, indicating that the implementation of Acuros XB during the commissioning process can be performed without degrading the quality of treatments previously commissioned with AAA.