System, apparatus and methods specialized for breast and related tissue radiation therapy and imaging of a prone patient but also usable for supine patient if desired or needed. At a point in time when the integral output voltage has reached a predetermined level, or at a point in time determined by timing of a predetermined period, the integral output voltage is reduced in absolute value by flowing into or out of the condenser a constant current supplied by a constant current source. The requestor is communicated whether permission is granted. When this indication indicates that the multicast packet was not received, the multicast packet is retransmitted to the plurality of mobile devices and to the group of MSs.