title: In reply to Furweger et al. (Int J Radiat Oncol Biol Phys DOI: 10.1016/j.ijrobp.2009.11.030).
authors.forename: Lijun
authors.initials: L
authors.lastname: Ma
authors.forename: Arjun
authors.initials: A
authors.lastname: Sahgal
authors.forename: David
authors.initials: D
authors.lastname: Larson
mesh_terms: D006801:Humans; D009068:Movement; D019047:Phantoms, Imaging; D016634:Radiosurgery / Q000379:methods*; D012371:Robotics / Q000379:methods*; D013131:Spine / Q000601:surgery*