Dose implications of fluoroscopy-guided positioning (FGP) for lumbar spine examinations prior to acquiring plain film radiographs.

Fluoroscopy is increasingly being used as a positioning device prior to obtaining plain film radiographs. This is particularly true for those examinations where the type of projection and habitus of the patient present difficulties. An example is the examination of the lumbar spine; especially the L5/S1 projection. The purpose of this study was to determine the effect of fluoroscopy-guided positioning (FGP) on patient dose. The study assessed the difference in dose-area product (DAP) between conventional film-screen radiography (FSR) and a FGP assisted series of the lumbar spine. DAP values were monitored on 102 patients (50 FSR, 52 FGP) over 7 (4 FSR, 3 FGP) study sites. The median values for all FGP and FSR procedures were 8.3 Gy cm(2) and 12.5 Gy cm(2), respectively. The differences in doses were attributed to lower mAs and tighter collimation used in FGP assisted procedures. The study has demonstrated that it is possible to achieve lower DAP values using FGP. What now has to be asked is whether FGP should be acknowledged and further introduced into clinical practice. If so, there is a need for careful monitoring and reporting of dose so that strict protocols can be set in place to ensure the ALARA principle is enforced.