Background: On-site physical quality assurance (QA) was performed in the participating centers of the CHARTWEL-Bronchus trial to ensure that physical and technical treatment parameters correspond with the requirements of this trial.
Material And Methods: Questionnaires were sent to the clinics to obtain information on the equipment and in-house QA policies. In addition, two phantoms with drillings for an ionization chamber were shipped with detailed instructions for CT-based treatment planning of a fixed field (RW3 phantom) and a standardized isocentric 3-field technique (Rando humanoid phantom).