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. The capability of the SARRP to deliver highly focused beams to multiple animal models provides new research opportunities that more realistically bridge laboratory research and clinical translation. This paper describes the design and operation of the SARRP for precise radiation delivery. Different delivery procedures are presented which enable the system to radiate through a series of points, representative of a complex shape. A particularly interesting case is shell dose irradiation, where the goal is to deliver a high dose of radiation to the shape surface, with minimal dose to the shape interior. 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.

We created an image-guided robot system to assist with skull base drilling by integrating our Steady Hand Robot with a Medtronic StealthStationreg Navigation System via its Stealthlink portal. The objective of this procedure is to create a opening in the skull base to allow access for neurosurgical interventions such as aneurysm clipping or tumor biopsy. The motivation for introducing an image-guided robot is to improve safety by preventing the surgeon from violating critical structures during the drilling procedure. Our approach is to attach the cutting tool to the robot end-effector and operate the robot in a cooperative control mode, where robot motion is determined from the forces and torques applied by the surgeon. We employ "virtual fixtures" to constrain the motion of the cutting tool so that it remains in the safe zone that was defined on a preoperative CT scan. This paper presents the system design and the results of phantom experiments performed with a synthetic skull.