title: An x-ray image guidance system for small animal stereotactic irradiation.
abstract: An x-ray image-guided small animal stereotactic irradiator was developed and characterized to enable tumor visualization and accurate target localization for small field, high dose irradiation. The system utilizes a custom collimation system, a motorized positioning system (x, y, θ), a digital imaging panel and operating software, and is integrated with a commercial x-ray unit. The essential characteristics of the irradiator include small radiation fields (1-10 mm), high dose rate (>10 Gy min(-1)) and submillimeter target localization. The software enables computer-controlled image acquisition, stage motion and target localization providing simple and precise automated target localization. The imaging panel was characterized in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and spatial resolution. Overall localization accuracy and precision were assessed. SNR, CNR and spatial resolution are 24 dB, 21 dB and 2.8 lp mm(-1), respectively, and localization accuracy is approximately 65 µm with 6 µm precision. With the aid of image guidance, system performance was subsequently used to evaluate radiation response in a rat orthotopic lung tumor effectively sparing normal tissues and in a mouse normal lung. The capabilities of 3D treatment and cone-beam computed tomography are presented for 3D localization and delivery as a work in progress.
authors.affiliation: Department of Radiation Oncology, UT Southwestern Medical Center at Dallas, Dallas, TX 75235, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Song
authors.forename: R
authors.initials: R
authors.lastname: Pidikiti
authors.forename: S
authors.initials: S
authors.lastname: Stojadinovic
authors.forename: M
authors.initials: M
authors.lastname: Speiser
authors.forename: S
authors.initials: S
authors.lastname: Seliounine
authors.forename: D
authors.initials: D
authors.lastname: Saha
authors.forename: T D
authors.initials: TD
authors.lastname: Solberg
mesh_terms: D000818:Animals; D008168:Lung / Q000000981:diagnostic imaging / Q000528:radiation effects; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery; D051379:Mice; D023421:Models, Animal; D016634:Radiosurgery / Q000295:instrumentation / Q000662:veterinary*; D051381:Rats; D015203:Reproducibility of Results; D012984:Software; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000662:veterinary*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000662:veterinary*