Defining Target Volumes for Stereotactic Ablative Radiotherapy of Early-stage Lung Tumours: A Comparison of Three-dimensional 18F-fluorodeoxyglucose Positron Emission Tomography and Four-dimensional Computed Tomography

Conventional three-dimensional 18F-FDG PET-derived target volumes for lung stereotactic ablative radiotherapy did not correspond well with those derived from four-dimensional CT, including those in routine clinical use (MIPMOD ITV). Caution is required in using three-dimensional PET for motion encompassing target volume delineation.