Medical physics
Real-time intrafraction 3D spine tracking using gantry-mounted kV imaging for single fraction high dose functional radiosurgery
By Xing S, Meyer S, Zhang L and 5 others.
Abstract
Background
Spinal nerve root ablation of 70-90 Gy with single fraction stereotactic radiosurgery (SRS) delivered in short partial arcs (30-60 degrees) is an emerging treatment for managing chronic thoracoabdominal wall pain. The proximity of the target to spinal cord and the high per fraction dose demand intrafraction motion monitoring with sub-millimeter accuracy. Pre-treatment cone-beam CT (CBCT) and intermittent room-mounted triggered kV imaging do not provide continuous internal anatomical verification during beam delivery. Gantry-mounted real-time tracking solutions have been mostly validated for full arc stereotactic body radiation therapy (SBRT) at substantially lower doses.
Purpose
We report comprehensive evaluations of a gantry-mounted, real-time 3D kV spine tracking system based on template matching of continuously acquired fluoroscopic images. Tracking performance was assessed under the demanding conditions of short-arc, high-dose functional SRS. We also present its first clinical use during spinal nerve root ablation for chronic thoracoabdominal wall pain.