TECHNIQUES FOR REDUCING INTERVENTIONAL NEURORADIOLOGIC SKIN DOSE - TUBE POSITION ROTATION AND SUPPLEMENTAL BEAM FILTRATION

PURPOSE: To limit the side effects of interventional neuroradiologic r adiation, such as epilation, by applying a technique involving tube po sition rotation and by adding a supplemental inexpensive primary beam filter; and to show the dose effect of modifying technical factors. ME THODS: Combined skin dose from fluoroscopy and digital subtraction ang iography was measured with an array of 16 thermoluminescent dosimeters during interventional neuroradiologic procedures in 12 control subjec ts, in 18 patients whose procedures included addition of an inexpensiv e primary beam filter (0.5 mm aluminum/0.076 mm copper), and in 10 pat ients in whom the tube position was rotated, additional primary beam f iltration was used, and close attention was paid to technique. RESULTS : Maximum thermoluminescent dosimetric measurements obtained with exis ting machine filtration ranged from 0.31 to 2.70 Gy in the control gro up (mean, 1.51 +/- 0.88); 0.25 to 2.42 Gy in the group with additional filtration alone (mean 0.96 +/- 0.64; average dose reduction, 36%); a nd 0,13 to 1.23 Gy in the group with additional filtration, tube posit ion rotation, and close attention to technique (mean, 0.58 +/- 0.34; a verage dose reduction, 63%). Differences were statistically significan t. CONCLUSIONS: Greater than 50% skin dose reductions were documented during interventional neuroradiologic procedures by combining tube pos ition rotation, supplemental primary beam filtration, and technical mo difications.