The RGS Orbiter

The Company has an exclusive worldwide distribution agreement with American Radiosurgery. Inc. American Radiosurgery, Inc produces the Rotating Gamma System® RGS Orbiter™, the first gamma knife type device that can treat tumors of the head as well as the rest of the body. The Rotating Gamma System, RGS Orbiter™ is a newly designed Cobalt-60 based radiosurgery Gamma System and capable of treating small and mid-size lesions of the total body of the patient. The patient is fixed to the treatment table with an immobilization device to avoid any patient movement during treatment. In case of a skull treatment, the patient’s head is immobilized via a standard stereotactic head frame. When other parts of the patient are treated the fixation device is an inflatable body shell. The precision of treatment achievable in the skull region is therefore about 0.5 mm when the stereotactic frame is used; the precision in other body locations using the inflatable immobilization is about 2mm. The treatment head houses 42 sources of Cobalt-60 arranged in one line over a circular segment of +/- 25 degrees as seen from the isocenter around the patient’s length axis, if the table is in the home position. The source isocenter distance is 469 mm. The table is in its “home” position when the long axis of the table is aligned within the center plane of the “C arm” structure. The table can rotate around a vertical axis (“B axis”) through the isocenter of + /- 90 degrees. The table also can be moved in the 3 linear coordinate axis x, y, and z. During treatment the treatment head of the machine, containing the 42 sources moves from the head “home” position, this is the “0 degree” top vertical position to the lowest position at 180 degrees around the horizontal “C” axis and back to the “0” position. This movement is a semi-circle arching with speeds between 0 and 6 degrees per second. Therefore 6 different mechanical movements are involved:

1)  Moving of the treatment head in semi-circles from 0 to 180 degrees and back. The numbers of executed semi circles are dependent on the total treatment time.

2)  Rotational movement of the patient table around the vertical axis.

3)  X, Y and Z movement of the table.

4)  Beam “on” and Beam “off” movement.

All mechanical movements are computer controlled and depending on the chosen treatment plan one or all possible mechanical movements are executed during treatment to simulate a 360-degree rotational treatment, half of the treatment time the patient table would be in the – 90-degree position and half of the treatment time in the + 90-degree position, while the treatment head moves “down” and “up” in the semi-circle. The RGS Orbiter consists of the gamma-ray treatment unit, the control system, protection, and safety system, the stereotactic localization system, and the treatment planning system. The treatment planning system connects to the diagnostic imaging devices and allows downloading of the treatment parameter to the RGS Vertex Orbiter. The treatment unit consists of the source unit, the collimating mechanisms, the treatment table, and the shielding structure. RGS Orbiter control system is an integration of user interface, electrical hardware, and control software. Its function is to provide accurate and consistent treatment based on the predefined treatment parameters while ensuring the safety of the patient and the operating personnel. The Radiation Protection and Operation Safety System include a video system, intercom system, radiation alarm system, interlocks and control panel. Target delineation and accurate positioning rely on the stereotactic localization system.