Room: Stars at Night Ballroom 4
Accounting for temporal anatomic changes that occur during dose delivery is one of the key scientific and clinical challenges of modern cancer radiotherapy (RT). These anatomic changes reduce image quality and targeting accuracy, which in turn lead to geometric and dosimetric errors. Management of intrafraction motion is becoming ever more important as the RT community adopts increasingly potent RT regimens (dose escalation, hypofractionation, SBRT), and modalities (protons, carbon ions). The task of intrafraction motion management consists of two, in principle, independent components (i) real-time position monitoring and (ii) real-time patient and/or beam adaptation. Clinical as well as investigational solutions integrate one (or sometimes multiple) system(s) from each group (e.g., surface photogrammetry and deep-inspiration breathhold, optical+kV x-ray imaging and beam tracking). Because most of these technologies were originally developed in the conventional (photon) RT setting, their adaptation and deployment in the particle therapy setting involves unique challenges.
The purpose of this session is to
â€¢ summarize the current state-of the-art motion management techniques
â€¢ understand the outstanding problems that need to be addressed
â€¢ examine ongoing scientific and technological advances that are expected to be clinically
translated in the near future.
This session will be divided into five parts, followed by a panel discussion (20 mins each = 120 mins total);
(i) Position Monitoring â€“ State of the Art: Current technologies for position monitoring will be discussed. These include optical marker-based systems (RPM, Polaris), abdominal pressure belt, surface photogrammetry (VisionRT, C-RAD), internal radiopaque (gold seeds, coils) or electromagnetic (Calypso) fiducials, and combinations thereof (external optical + internal radioopaque markers).
Speaker â€“Laura Cervino
(ii) Position Monitoring â€“ Future Roadmap: The talk will focus on multi-cycle, real-time volumetric motion models using 4DCT, cine CT, and CBCT. Advantages, limitations and in-phantom and in-patient validation of these models will be discussed. Finally, MRI-based motion monitoring in integrated MRI+linac systems will be briefly described.
Speaker â€“ Amit Sawant
(iii) In-room patient/beam adaptation â€“ State of the Art: We will describe techniques for abdominal compression, breath-hold (patient-controlled and device controlled) techniques, respiratory gating, and real-time beam tracking using Cyberknife and gimballed linac (Vero).
(iv) In-room patient/beam adaptation â€“ Future Roadmap: This talk will discuss patient-specific Audiovisual feedback for breathing regularization, and real-time MLC tracking. Early results from prospective clinical trials for these technologies will be presented
Speaker â€“ Paul Keall
(v) Intrafraction Motion Management for Particle therapy: The unique challenges presented by intrafraction motion for particle beams will be discussed. The adaptation of currently available motion management techniques for particle therapy will be described and future strategies will be discussed.
Speaker â€“ Lei Dong
(vi) Panel Discussion â€“ All speakers.
Funding Support, Disclosures, and Conflict of Interest: Amit Sawant receives research funding and support from the National Institutes of Health, Varian Medical Systems and VisionRT Ltd.
Not Applicable / None Entered.
Not Applicable / None Entered.