A phase space model of a Versa HD linear accelerator for application to Monte Carlo dose calculation in a real-time adaptive workflow.

Purpose: This study aims to develop and validate a simple geometric model of the accelerator head, from which a particle phase space can be calculated for application to fast Monte Carlo dose calculation in real-time adaptive photon radiotherapy. With this objective in view, the study investigates whether the phase space model can facilitate dose calculations which are compatible with those of a commercial treatment planning system, for convenient interoperability.

Materials And Methods: A dual-source model of the head of a Versa HD accelerator (Elekta AB, Stockholm, Sweden) was created.

Daily adaptive radiotherapy for patients with prostate cancer using a high field MR-linac: Initial clinical experiences and assessment of delivered doses compared to a C-arm linac.

Introduction: MR-guided adapted radiotherapy (MRgART) using a high field MR-linac has recently become available. We report the estimated delivered fractional dose of the first five prostate cancer patients treated at our centre using MRgART and compare this to C-Arm linac daily Image Guided Radiotherapy (IGRT).

Methods: Patients were treated using adapted treatment plans shaped to their daily anatomy.

Automatic reconstruction of the delivered dose of the day using MR-linac treatment log files and online MR imaging.

Background And Purpose: Anatomical changes during external beam radiotherapy prevent the accurate delivery of the intended dose distribution. Resolving the delivered dose, which is currently unknown, is crucial to link radiotherapy doses to clinical outcomes and ultimately improve the standard of care.

Material And Methods: In this study, we present a dose reconstruction workflow based on data routinely acquired during MR-guided radiotherapy.