that information to the control area 20 where it can be observed and monitored by the operator 40 not shown fig6 is a flow diagram of the gamma system visual inspection device 10 of the present invention in step s 100 an indexing error occurs in the electronic monitor in step s 102 the mechanical indicator 22 shows the indexing error however as shown in step s 104 the operator 40 cannot enter the treatment room during the operation of the rotating gamma system 12 due to the radiation that is applied to the patient 14 in step s 106 the video camera 16 and the lights 18 of the gamma system visual inspection device 10 provide a visual picture of the mechanical indicator 22 in the control area 20 fig7 is a block diagram of the gamma system visual inspection device 10 of the present invention the rotating gamma system 12 is used to perform radiosurgery on lesions in the brains of patients 14 as well as in other medical procedures the source carrier 30 and the collimator carrier 32 are located within the rotating gamma system 12 and rotate independently of one another the rotation of the source carrier 30 and the collimator carrier 32 is electronically controlled by a rotation monitor 34 which is operated by the operator 40 in the control area 20 shown hereinabove with specific reference to fig5 the electronic encoder 24 electronically tracks.