On the trail of CBCT-guided adaptive rectal boost radiotherapy, does daily delineation require a radiation oncologist?

Introduction: Dose-escalation radiotherapy for rectal tumours is increasingly considered as a non-operative approach, with online-adaptive radiotherapy (oART) supporting this approach by correcting inter-fraction tumour position errors. However, using cone-beam computed tomography (CBCT)-guided oART requires daily target volume delineation by different operators, leading to inter-operator delineation variability and potential dosimetric issues. This study aims to compare and quantify the inter-operator and inter-professional delineation variability of the rectal boost volume on CBCT, including volumes by an automatically delineated oART treatment planning system.

Lung and Liver Stereotactic Body Radiation Therapy During Mechanically Assisted Deep Inspiration Breath-Holds: A Prospective Feasibility Trial.

Purpose: Radiation therapy for tumors subject to breathing-related motion during breath-holds (BHs) has the potential to substantially reduce the irradiated volume. Mechanically assisted and noninvasive ventilation (MANIV) could ensure the target repositioning accuracy during each BH while facilitating treatment feasibility through oxygen supplementation and a perfectly replicated mechanical support. However, there is currently no clinical evidence substantiating the use of MANIV-induced BH for moving tumors.

Markerless liver online adaptive stereotactic radiotherapy: feasibility analysisCervantes.

. Radio-opaque markers are recommended for image-guided radiotherapy in liver stereotactic ablative radiotherapy (SABR), but their implantation is invasive. We evaluate in thisstudy the feasibility of cone-beam computed tomography-guided stereotactic online-adaptive radiotherapy (CBCT-STAR) to propagate the target volumes without implanting radio-opaque markers and assess its consequence on the margin that should be used in that context.

Cone-beam computed tomography-guided online-adaptive radiotherapy for inoperable right colon cancer: First in human.

We report the case of a medically inoperable patient with localised colon cancer. Due to symptomatic bleeding, definitive radiotherapy (5 daily fractions of 5 Gy) has been performed using cone-beam computed tomography-based online-adaptive radiotherapy (ART). Online-ART enables compensation of interfraction motion of abdominal organs by performing daily delineation of organs at risk (OARs) and target volumes.