An x-ray image guidance system for small animal stereotactic irradiation

Phys Med Biol. 2010 Dec 7;55(23):7345-62. doi: 10.1088/0031-9155/55/23/011. Epub 2010 Nov 16.


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.

MeSH terms

  • Animals
  • Lung / diagnostic imaging
  • Lung / radiation effects
  • Lung Neoplasms / diagnostic imaging
  • Lung Neoplasms / surgery
  • Mice
  • Models, Animal
  • Radiosurgery / instrumentation
  • Radiosurgery / veterinary*
  • Rats
  • Reproducibility of Results
  • Software
  • Surgery, Computer-Assisted / instrumentation
  • Surgery, Computer-Assisted / veterinary*
  • Tomography, X-Ray Computed / instrumentation
  • Tomography, X-Ray Computed / veterinary*