title: MRI-guided lung SBRT: Present and future developments.
abstract: Stereotactic body radiotherapy (SBRT) is rapidly becoming an alternative to surgery for the treatment of early-stage non-small cell lung cancer patients. Lung SBRT is administered in a hypo-fractionated, conformal manner, delivering high doses to the target. To avoid normal-tissue toxicity, it is crucial to limit the exposure of nearby healthy organs-at-risk (OAR). Current image-guided radiotherapy strategies for lung SBRT are mostly based on X-ray imaging modalities. Although still in its infancy, magnetic resonance imaging (MRI) guidance for lung SBRT is not exposure-limited and MRI promises to improve crucial soft-tissue contrast. Looking beyond anatomical imaging, functional MRI is expected to inform treatment decisions and adaptations in the future. This review summarises and discusses how MRI could be advantageous to the different links of the radiotherapy treatment chain for lung SBRT: diagnosis and staging, tumour and OAR delineation, treatment planning, and inter- or intrafractional motion management. Special emphasis is placed on a new generation of hybrid MRI treatment devices and their potential for real-time adaptive radiotherapy.
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK. Electronic address: martin.menten@icr.ac.uk.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Menten
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wetscherek
authors.affiliation: Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London, UK. Electronic address: m.fast@nki.nl.
authors.forename: Martin F
authors.initials: MF
authors.lastname: Fast
mesh_terms: D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*; D008279:Magnetic Resonance Imaging; D016634:Radiosurgery / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*
keywords: Adaptive radiotherapy; Hypo-fractionation; Lung cancer; MRI guidance; SBRT