Abstract: The apparatus for determining the position of radioactive seeds in a pre-loaded brachytherapy needle includes a pickup unit into which the loaded needle is inserted. A scintillating (phosphor) screen responsive to radiation from the seeds produces a light output of selected wavelength, which is then picked up by an optical array positioned along the screen. The resulting optical signals are then transmitted to a display assembly. The optical signals are focused and then applied to a CCD device. The output of the CCD device is processed by a microprocessor to produce a visual display of the radioactive seeds within the needle.

Abstract: The syringe includes a barrel (12) and first and second piston-like elements (16,18) which are adapted for fluid tight movement therein, wherein the first and second pistons (16,18) are connected by a flexible, thin cord (36). A hollow needle (28) is mounted on and extends from the front surface (24) of the first piston (16). The needle (28) communicates with the space between the first and second pistons (16,18). A plunger (32) is attached to the rear surface (31) of the second piston (18) and extends from the rear of the syringe in conventional fashion. In the forwardmost position of the first piston (16), the needle (28) extends outwardly from the front end of the syringe barrel (12) but in the rearmost position, the needle (28) is within the barrel (12).