Funding for this research was provided by:
Received: 11 February 2021
Accepted: 12 July 2021
First Online: 21 July 2021
: This retrospective study was exempt from requiring ethics approval. Bavarian state law (Bayrisches Krankenhausgesetz/Bavarian Hospital Law § 27 Absatz 4 Datenschutz (Dataprotection)) allows the use of patient data for research, provided that any person’s related data are kept anonymous. German radiation protection laws request a regular analysis of outcomes in the sense of quality control and assurance, thus in the case of purely retrospective studies no additional ethical approval is needed under German law.
: Not applicable.
: The Department of Radiation Oncology of the University Hospital, LMU Munich has research agreements with Elekta, Inc. and ViewRay, Inc.