ESTRO 2024 - Abstract Book

S4268

Physics - Intra-fraction motion management and real-time adaptive radiotherapy

ESTRO 2024

Ray Pilot system allows tracking prostate motion, guaranteeing that the position of the prostate is within the established tolerance. As a result, we can deliver extreme hypofractionation treatments guaranteeing safety and precision.

Keywords: Ray Pilot, Adaptative, Real-Time

References:

1. Electromagnetic Real-Time positioning in Radiotherapy of prostate cancer-initial clinical results.

E. Castellanos, M. Hjelm Ericsson, B. Sorcini, U. Green, S. Nilsson, B. Lennernäs,

Radiotherapy and Oncology, 2012

2.Treatment outcome and compliance to dose-intensified linac-based SBRT for unfavorable prostate tumors using a novel real-time organ-motion tracking

Raffaella Lucchini, Denis Panizza, Riccardo Ray Colciago , Veronica Vernier, Martina Camilla Daniotti, Valeria Faccenda and Stefano Arcangeli

Radiation and Oncology 2021

1585

Digital Poster

Online dose adaptation based on accumulated dose with zero PTV margin in rectal cancer radiotherapy

Lukas Schröder 1 , Lisa Wiersema 1 , Anja Betgen 1 , Corrie Marijnen 1 , Uulke van der Heide 1 , Jan-Jakob Sonke 1 , Erik van der Bijl 2 , Tomas Janssen 1 1 The Netherlands Cancer Institute, Radiation Oncology, Amsterdam, Netherlands. 2 Radboud University Medical Center, Radiation Oncology, Nijmegen, Netherlands

Purpose/Objective:

Current practice in online adaptive radiotherapy is to daily adapt the treatment plan to the geometry of the day. This allows for a reduction of uncertainties and therefore smaller PTV margins. In this work we introduce online dose adaptive radiotherapy, where the treatment plan is adapted not only to the geometry of the day but also to the accumulated dose delivered in previous fractions. To illustrate the concept we consider rectal cancer patients that were previously treated with 5 x 5 Gy conventional online adaptive radiotherapy. We retrospectively recreate treatment plans for the first 4 fractions, however with 0 mm PTV margins. The final fraction is used to compensate for potential underdosage to the CTV. Since this approach further personalizes the treatment by including treatment-