The Story: “Don’t. Cross. The streams. It would be bad.” That’s basically what goes through a lot of minds when it comes to arranging photon streams for multiple brain mets in a single radiosurgery (SRS) treatment. But have no fear. Varian’s HyperArc takes specialized dosimetry techniques and puts them in an end-to-end software package that lets you generate highly conformal SRS treatments for multiple targets using a single isocenter. At its heart, the technique was initially developed to create dose distributions identical to those of the Gamma Knife, all via linear accelerator. First, concentric “rings” around each of the targets are used as optimizing structures to create steep dose gradients. Nest, an axial and (usually) two off-axis vertex arcs are used to rapidly deliver the dose. Last, kick back and listen to the MU’s tick.
Bottom Line: HyperArc is a slick software upgrade that allows you to do single isocenter, multitarget SRS using the TrueBeam package. Beam on.