Megavoltage cone beam digital tomosynthesis (MV-CBDT) for image-guided radiotherapy: a clinical investigational system.
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.
Pang
G
G
Odette Cancer Centre, Toronto, Canada. geordi.pang@sunnybrook.ca
Bani-Hashemi
A
A
Au
P
P
O'Brien
P F
PF
Rowlands
J A
JA
Morton
G
G
Lim
T
T
Cheung
P
P
Loblaw
A
A
D002138:Calibration; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation*; D006801:Humans; D019047:Phantoms, Imaging; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*