Room: Stars at Night Ballroom 1
Katia Parodi - Advances in ion imaging and range verification
When charged particles traverse through a medium, many interactions occur which cause the particles to slow down and eventually stop. Ion beam range is a source of uncertainty and several imaging techniques have been developed to better estimate particle range as well as verify particle range in order to maximize the benefit of dose sparing offered by particle therapy. This lecture provides an overview of the different physical interactions that lead to secondary emissions such as positrons, prompt gammas (PG) and acoustic waves that can be imaged for the purpose of verifying particle beam range.
1. Understand the implications of particle range uncertainty
2. Understand the different types physical interactions that lead to secondary emissions
3. Understand the different techniques that can be used for range verification (PET, PG gamma imaging, ion acoustic imaging).
Xuanfeng Ding - Spot-scanning Proton Arc therapy: from a concept to reality.
Proton arc therapy based on the passive scattering technique has been experimentally explored by Sandison et al in 1997. In the past ten years, the particle beam therapy society has entered the era of pencil beam scanning (PBS) technique where proton beam therapy is able to paint the target spot by spot and layer by layer just like a 3D printing machine in patientâ€™s body. Since then, the concept of proton arc therapy based on PBS technique has drawn significant interest. Multiple approaches have been proposed in order to implement proton arc therapy in clinic such as Distal End Tracking (DET) and mono-energetic proton arc therapy. While dosimetric quality was significantly improved based on these treatment planning simulation studies, the feasibility of proton arc delivery and treatment plan robustness were not addressed. In 2016, we proposed a new optimization algorithm, Spot-scanning Proton Arc (SPArc) therapy, based on the iterative approach integrating with robust optimization engine. Such proposed approach generated the first proton arc plan with a robust plan quality which has also the potential to be implemented into the existing proton system. In Aug. 2018, with the collaboration of Ion Beam Application Inc. (IBA, Belgium), the first SPArc treatment was successfully delivered on a phantom in Beaumont Proton Therapy Center. The goal of this talk is to review the development process of such technique from a concept into an actual treatment delivery using a continuous rotational gantry.
1. Understand the motivation for proton arc therapy
2. Understand the potential clinical advantages of using SPArc technique to mitigate the interplay effect in mobile tumor treatment, improving dose conformability and treatment delivery efficiencies.
Hugo Bouchard - Multi-energy CT for dose calculation in particle therapy
The accuracy of particle therapy dose calculation relies on the accuracy of patient composition data. A major source of uncertainty in is the conversion of x-ray CT number from a single energy CT (SECT) to stopping power ratio (SPR) of the particle relative to water. Currently, the most reliable and widely used method is the stoichiometric calibration of Schneider et al (1996 Phys. Med. Biol. 41 111â€“24). With the commercial availability of dual energy CT (DECT)and spectral CT scanners, more accurate methods of estimating tissue properties have been developed for use in estimating SPR for analytical type dose calculation algorithms. Further improvements can be made with transport based dose calculation algorithms such as Monte Carlo techniques which benefit from the elemental composition data that is afforded by multi-energy CT data to improve the accuracy particle therapy dose calculation.
1. Understand the technique of multi-energy CT for deriving material composition data
2. Understand the benefit and use of multi-energy CT for Monte Carlo dose calculation.
Funding Support, Disclosures, and Conflict of Interest: X. Ding received funding from Ion Beam Applications (IBA, Belgium).