Future Developments in Charged Particle Therapy: Improving Beam Delivery for Efficiency and Efficacy

The physical and clinical benefits of charged particle therapy (CPT) are well recognized. However, the availability of CPT and complete exploitation of dosimetric advantages are still limited by high facility costs and technological challenges. There are extensive ongoing efforts to improve upon these, which will lead to greater accessibility, superior delivery, and therefore better treatment outcomes. Yet, the issue of cost remains a primary hurdle as utility of CPT is largely driven by the affordability, complexity and performance of current technology. Modern delivery techniques are necessary but limited by extended treatment times. Several of these aspects can be addressed by developments in the beam delivery system (BDS) which determines the overall shaping and timing capabilities enabling high quality treatments. The energy layer switching time (ELST) is a limiting constraint of the BDS and a determinant of the beam delivery time (BDT), along with the accelerator and other factors. This review evaluates the delivery process in detail, presenting the limitations and developments for the BDS and related accelerator technology, toward decreasing the BDT. As extended BDT impacts motion and has dosimetric implications for treatment, we discuss avenues to minimize the ELST and overview the clinical benefits and feasibility of a large energy acceptance BDS. These developments support the possibility of advanced modalities and faster delivery for a greater range of treatment indications which could also further reduce costs. Further work to realize methodologies such as volumetric rescanning, FLASH, arc, multi-ion and online image guided therapies are discussed. In this review we examine how increased treatment efficiency and efficacy could be achieved with improvements in beam delivery and how this could lead to faster and higher quality treatments for the future of CPT.

Unique Beam Scanning Device for Active Beam Delivery System in Proton Therapy

A new Beam Delivery System (BDS) has been proposed for a proton therapy project, partially funded, called AMIDERHA. That BDS is characterized by an active scanning system which irradiates target with a pencil beam. The feature of this project was the using of an accelerator Linac with variable final energies and the Robotized Patient Positioning System instead of the traditional gantry. The active BDS of AMIDERHA then does not include a gantry and a pencil beam scanning system with a relatively long Source to Axis Distance (SAD) could be used. In this condition, the using of a unique device capable of scanning the beam for both horizontal and vertical plane in the active BDS of the project is possible. In this contribution this new beam scanning device will be presented. Furthermore, a preliminary design of the device and the trajectory simulations for beam parameter optimization will also be discussed.