Design of commissioning process for Halcyon™ linac with a new rigid board: A clinical experience.

• Verification of reference beam profiles (RBPs) for preconfigured Halcyon. • Comparison of RBPs and accurate measured beam profiles (MBPs) with novel rigid board. • Measurements of beam profiles with water tank on the board bridged Halcyon bore. • Supplied RBPs can be used as golden beam data due to good agreement with MBPs. • This work should be useful for new Halcyon users. This study performed the accurate measurements of beam profiles with a new rigid board, which was consistent with the supplied reference beam profiles (RBPs) for clinical Halcyon model. Percentage depth doses (PDDs), lateral and diagonal dose profiles were measured and compared with RBPs. A water tank was set on the rigid board bridged Halcyon bore without sagging and source-to-surface distance was 90.0 cm. Field sizes were from 2.0 to 28.0 cm squares and depths of lateral and diagonal dose profiles were 1.3, 5.0, 10.0, and 20.0 cm. For the PDD, the depth of maximum dose (d max), PDD value at depth of 10.0 cm (PDD 10), and absolute dose difference (DD) between RBP and measured beam profiles (MBP) were evaluated. For lateral and diagonal dose profiles, DDs for the whole and divided areas (central, shoulder, and extended areas) defined by third derivative, and distance-to-agreement (DTA) in the penumbra area were evaluated. For PDDs, the differences of d max and PDD 10 and DD beyond the d max were within 1.0 mm, 0.3%, and 1.0%, respectively. For lateral and diagonal dose profiles, the DDs reached approximately 5.0% in the whole area because of penumbra area, while the DDs in the central, shoulder, and extended areas were within 1.0%, 2.0%, and 1.0%, respectively. The DTAs in the penumbra area were within 0.8 mm. The supplied RBPs can be used clinically owing to the good agreement with the accurate MBPs with rigid board. [ABSTRACT FROM AUTHOR]