title: Megavoltage cone beam digital tomosynthesis (MV-CBDT) for image-guided radiotherapy: a clinical investigational system.
abstract: Cone beam digital tomosynthesis (CBDT) is a new imaging technique proposed recently as a rapid approach for creating tomographic images of a patient in the radiotherapy treatment room. The purpose of this work is to investigate the feasibility of performing megavoltage (MV) CBDT clinically. A clinical investigational MV-CBDT system was installed on an existing LINAC. After the installation, the treatment machine can be operated in two distinct modes: (1) normal clinical treatment mode; (2) CBDT mode, in which tomographic images of the patient can be obtained using MV-CBDT. Various calibration and phantom measurements were performed on the system, followed by a patient study. Our phantom measurements have shown that: (1) for the same imaging dose, MV-CBDT has the same signal-difference-to-noise ratio as megavoltage cone beam computed tomography (MV-CBCT); (2) MV-CBDT has a better spatial resolution than MV-CBCT in the planes of reconstruction but a worse spatial resolution in the direction perpendicular to the planes of reconstruction. MV-CBDT patient images were also obtained and compared to that of MV-CBCT. We have demonstrated that it is clinically feasible to perform MV-CBDT in the treatment room for image-guided radiotherapy.
authors.affiliation: Odette Cancer Centre, Toronto, Canada. geordi.pang@sunnybrook.ca
authors.forename: G
authors.initials: G
authors.lastname: Pang
authors.forename: A
authors.initials: A
authors.lastname: Bani-Hashemi
authors.forename: P
authors.initials: P
authors.lastname: Au
authors.forename: P F
authors.initials: PF
authors.lastname: O'Brien
authors.forename: J A
authors.initials: JA
authors.lastname: Rowlands
authors.forename: G
authors.initials: G
authors.lastname: Morton
authors.forename: T
authors.initials: T
authors.lastname: Lim
authors.forename: P
authors.initials: P
authors.lastname: Cheung
authors.forename: A
authors.initials: A
authors.lastname: Loblaw
mesh_terms: D002138:Calibration; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation*; D006801:Humans; D019047:Phantoms, Imaging; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*