Radiation exposure during fluoroscopy: should we be protecting our thyroids?

Recent reports on thyroid cancer among Australian orthopaedic surgeons prompted the present study which sought to evaluate the effectiveness of lead shielding in reducing radiation exposure (RE) to the thyroid region during endo-urological procedures.

Radiation exposure to the thyroid region of the surgeon and scrubbed nurse was monitored for 20 consecutive operations over a 6-week period by thermoluminescent dosimeters (TLD). A TLD was placed over and underneath a thyroid shield of 0.5 min lead equivalent thickness to monitor the effect of shielding.

Eight percutaneous nephrolithotomies, seven retrograde pyelograms and ureteric stentings and five ureteroscopies for calculous disease were monitored. Total exposure time was 63.1 min. For the surgeon, the total cumulative RE over and under the lead shield was 0.46 and 0.02 mSv, respectively, equating to a 23-times reduction in RE if shielding was used. This effectively reduced RE to almost background levels, which was represented by the control TLD exposure (0.01 mSv).

Although RE without thyroid shields did not exceed current standards set by radiation safety authorities, no threshold level has been set below which thyroid carcinogenesis is unlikely to occur. Because lead shields are easy to wear and can effectively reduce RE to the thyroid region to near-background levels, they should be made easily available and used by all surgeons to avoid the harmful effects of radiation on the thyroid.