High-resolution, small animal radiation research platform with x-ray tomographic guidance capabilities

Int J Radiat Oncol Biol Phys. 2008 Aug 1;71(5):1591-9. doi: 10.1016/j.ijrobp.2008.04.025.


Purpose: To demonstrate the computed tomography, conformal irradiation, and treatment planning capabilities of a small animal radiation research platform (SARRP).

Methods and materials: The SARRP uses a dual-focal spot, constant voltage X-ray source mounted on a gantry with a source-to-isocenter distance of 35 cm. Gantry rotation is limited to 120 degrees from vertical. X-rays of 80-100 kVp from the smaller 0.4-mm focal spot are used for imaging. Both 0.4-mm and 3.0-mm focal spots operate at 225 kVp for irradiation. Robotic translate/rotate stages are used to position the animal. Cone-beam computed tomography is achieved by rotating the horizontal animal between the stationary X-ray source and a flat-panel detector. The radiation beams range from 0.5 mm in diameter to 60 x 60 mm(2). Dosimetry is measured with radiochromic films. Monte Carlo dose calculations are used for treatment planning. The combination of gantry and robotic stage motions facilitate conformal irradiation.

Results: The SARRP spans 3 ft x 4 ft x 6 ft (width x length x height). Depending on the filtration, the isocenter dose outputs at a 1-cm depth in water were 22-375 cGy/min from the smallest to the largest radiation fields. The 20-80% dose falloff spanned 0.16 mm. Cone-beam computed tomography with 0.6 x 0.6 x 0.6 mm(3) voxel resolution was acquired with a dose of <1 cGy. Treatment planning was performed at submillimeter resolution.

Conclusion: The capability of the SARRP to deliver highly focal beams to multiple animal model systems provides new research opportunities that more realistically bridge laboratory research and clinical translation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cone-Beam Computed Tomography / instrumentation*
  • Cone-Beam Computed Tomography / methods
  • Equipment Design
  • Mice
  • Monte Carlo Method
  • Rabbits
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted / instrumentation*
  • Radiotherapy Planning, Computer-Assisted / methods
  • Radiotherapy, Conformal / instrumentation*
  • Rats
  • Robotics / methods
  • Rotation
  • Technology, Radiologic / instrumentation
  • Technology, Radiologic / methods