Technological Developments and Future Perspectives in Particle Therapy: A Topical Review

In the last decades, important technological progress has been made to enhance the quality and efficiency of particle therapy treatments. Continuous improvements in dose delivery, treatment planning and verification techniques have led to higher-dose conformity and better sparing of healthy tissue. At the same time, particle therapy treatments are complex and much more expensive than conventional radiotherapy, and only highly specialized facilities can offer these treatments. Cost reduction is thus a strong drive behind technological developments in the field. The number of treatment facilities offering proton and carbon therapy has strongly grown in the last decades, and the amount of research efforts and innovations have increased continuously. From a technological perspective, advances in hardware are often accompanied by innovations in software and computation, and vice versa. In this review we will present a basic overview of technological advances in particle therapy hardware (accelerators, gantries, applications of superconductivity, treatment verification techniques), software (Monte Carlo simulations, treatment planning calculations), and studies toward clinical applications. By combining a broad selection of topics into a single review and by covering both proton and carbon therapy, we aim at providing the reader a unique overview of the evolution of various technologies developed for particle therapy.