1st TrueBeam in Austria goes clinical

On Jan 2, 2013, we started clinical treatments on TrueBeam "Blue" (S/N 1275). The machine is a TrueBeam STx (HD120 MLC) with the covers of a TrueBeam:

Members of the team in front of TrueBeam Blue

The first patient received an isocentric breast treatment with tangential fields, using Irregular Surface Compensators (ISC, a dynamic HD120-MLC technique).

The TrueBeam console screenshot shows the integrated image of the lateral field on the right:

TrueBeam screenshot after 1st patient treatment

Before treatment, isocenter was verified with paired kV-kV-images.

The second patient received a RapidArc treatment with a single arc. After CBCT, 3D-3D-match and applying the shift, isocenter was verified a second time with paired kV-kV-images (daily imaging will be kV-kV only).

First Flattening Filter Free Treatment

On Jan 17, FFF energies were used clinically for the first time. In a prostate treatment (including lymph nodes), the unflattened 10FFF energy resulted in better plan quality and shorter treatment time compared to the flattend 10 MV plan. With the 10FFF energy and its dose rate limit of 2400 MU/min, Gantry was allowed to run nearly at full speed during the whole arc, which resulted in a treatment time of 1.07 minutes.

The rightmost insert in the screenshot is the integrated fluence image of the RapidArc treatment. This is used for pretreatment verification of FFF-beams:

TrueBeam screenshot after 1st FFF treatment

The plan was QA'ed with EPIQA 3.0.5 before treatment. Gamma agreement index was 99.42%@2%/2mm, and 98.72%@2%/1mm.