Dual-source cone-beam CT for HDR brachytherapy in-suite imaging: Simulation studies of limited angle image...

C-arm cone-beam computed tomography (CBCT) in-suite imaging is often used in a brachytherapy suite. However, due to the limited rotation angle of the C-arm gantry and the dimension of the flat panel imager (FPI), CBCT images are often truncated and not suitable for treatment planning. In this simulation study, we present the design of a novel ultra-compact mobile dual-source CBCT (dCBCT) that can scan large field of view with half system rotation. Enabled by deep learning image reconstruction, it can perform ultra-short scans and stereoscopic imaging before and during high dose rate (HDR) treatments.

The dCBCT comprises two x-ray sources and a flat panel imager mounted on a C-arm gantry. The dual-sources configuration enables real-time stereoscopic imaging, also avoids data truncation problem of conventional C-arm CBCT. Simulation studies were performed to prove the concept of ultra-short scan of dCBCT. Deep Image Prior (DIP) image reconstruction without and with a Prior was also developed to reduce the scan angle.

The simulation studies of dCBCT show that it can achieve a sufficient reconstruction field of view with 180° rotation. DIP reconstruction reduces scanning angle to 135° without sacrificing image quality. With body profile as constraint, ultra-short scan with merely 90° system rotation can be achieved.

Powered by deep-learning based limited-angle image reconstruction, dCBCT can scan full body with a short scan, allowing rapid 3D and real-time planar imaging in brachytherapy suite.