Precision Irradiation and Delivery of Complex Dose Volumes for Small Animal Research

Babak Matinfar, Carnegie Mellon University

Small animal research allows detailed study of biological processes, disease progression and response to therapy with the potential to provide a natural bridge to the clinical environment. The Small Animal Radiation Research Platform (SARRP) is a novel and complete system capable of delivering multidirectional (focal), kilo-voltage radiation fields to targets in small animals under robotic control using cone-beam CT (CBCT) image guidance.

This talk provides a complete overview of the SARRP and extends on the calibration and radiation delivery capabilities of the system. A novel technique for the calibration of the treatment beam is presented, which employs an x-ray camera whose precise position need not be known. Different radiation delivery procedures enable the system to radiate through a series of points, representative of a complex shape. For the first time, a particularly interesting case of shell dose irradiation is challenged. The goal in peripheral dose distribution is to deliver a high dose of radiation to the shape surface, with minimal dose to the shape interior. This goal is achieved by geometrically creating a spherical shell through intersecting cylinders in the SARRP configuration. The ability to deliver a dose shell allows mechanistic research of how a tumor interacts with its microenvironment to sustain its growth and lead to its resistance or recurrence.