TURBO: A novel beam delivery system enabling rapid depth scanning for charged particle therapy

Charged particle therapy (CPT) is a well-established modality of cancer treatment and is increasing in worldwide presence due to improved accelerator technology and modern techniques. The beam delivery system (BDS) determines the overall timing and beam shaping capabilities, but is restricted by the energy variation speed: energy layer switching time (ELST). Existing treatment beamlines have a ±1% momentum acceptance range, needing time to change the magnetic fields as the beam is delivered in layers at various depths across the tumour volume. Minimising the ELST can enable the delivery of faster, more effective and advanced treatments but requires an improved BDS. A possibility for this could be achieved with a design using Fixed Field Alternating Gradient (FFA) optics, enabling a large energy acceptance to rapidly transport beams of varying energies. A scaled-down, novel system – Technology for Ultra Rapid Beam Operation (TURBO) – is being developed at the University of Melbourne, to explore the potential of rapid depth scanning. Initial simulation studies, beam and field measurements, project plans and clinical considerations are discussed.