OPTIMISATION OF SCATTER RADIATION TO STAFF DURING CT-FLUOROSCOPY: MONTE CARLO STUDIES.

Studies have shown that there is high radiation exposure to medical staff during computed tomography fluoroscopy (CTF)-guided procedures. This study aims to investigate staff dose reduction techniques considering the CTF gantry positioning in the room and room dimensions in addition to the conventional use of thyroid collars, aprons and eye goggles. A Toshiba Aquilion One 640 slice CT scanner and CTF room were modelled using SimpleGeo. Standing and supine adult mesh phantoms were used to represent the staff and patient. The models were spatially put together on one platform using VOXEL2MCNP. Based on this, MCNPX input files were generated for the studies. CTF gantry and staff positions, and CTF room size were varied for different scenarios. Effective, eye lens and thyroid dose to staff were estimated for each scenario. Additional means of possible dose reduction with respect to positioning of the CTF device and room layout are discussed.