No abstract

TCR has adequate radiation shielding ability for electron beams and could be employed instead of lead.

This study investigates whether a novel tungsten-containing rubber shield could be used as substitute shielding material in interventional radiology to reduce the occupational exposure of operators to scattered radiation from a patient. The tungsten-containing rubber is a lead-free radiation-shielding material that contains as much as 90% tungsten powder by weight. Air kerma rates of scattered radiation from solid-plate phantoms, simulating a patient, were measured with a semiconductor dosimeter at the height of the operator’s eye (1,600 mm from the floor), chest (1,300 mm), waist (1,000 mm), and knee (600 mm) with and without tungsten-containing rubber shielding (1–5 mm thickness). The tungsten-containing rubber and a commercial shielding material (RADPAD) were affixed onto the phantom on the operator’s side, and reductions in air kerma rates were compared. Reduction rates for tungsten-containing rubber shielding with thicknesses of 1, 2, 3, 4, and 5 mm at each height level were as follows: 70.37 ± 0.40%, 72.17 ± 0.29%, 72.95 ± 0.31%, 72.58 ± 0.35%, and 73.63 ± 0.63% at eye level; 76.36 ± 0.19%, 77.13 ± 0.10%, 77.36 ± 0.14%, 77.62 ± 0.25%, and 77.66 ± 0.14% at chest level; 67.78 ± 0.31%, 68.12 ± 0.19%, 68.88 ± 0.28%, 68.97 ± 0.14%, and 68.85 ± 0.45% at waist level; and 0.14 ± 0.94%, 0.72 ± 0.56%, 1.08 ± 0.74%, 1.77 ± 0.80%, and 1.79 ± 1.82% at knee level, respectively. Reduction rates with RADPAD were 61.80 ± 0.67%, 60.33 ± 0.61%, 64.70 ± 0.25%, and 0.14 ± 0.66% at eye, chest, waist, and knee levels, respectively. The shielding ability of the 1 mm tungsten-containing rubber was superior to that of RADPAD. The tungsten-containing rubber could be employed to minimize an operator’s radiation exposure instead of the commercial shielding material in interventional radiology.

Background/Aim: Spatially fractionated radiotherapy (grid therapy) can control some bulky tumors which is challenging for conventional radiotherapy. This study aimed to investigate whether a novel tungsten contained rubber (TCR) grid collimator can be employed in electron grid therapy. Materials and Methods: The TCR grid collimator placed on a solid water phantom, and percentage depth doses (PDDs) and lateral dose profiles were measured for 9 MeV electron beam with Gafchromic EBT3 films. At the lateral dose profile, the ratios of the dose in the areas with and without shielding (valley-to-peak ratios) were evaluated. Results: The d max values with the 1, 2 and 3 mm TCR grid collimators were 1.2, 1.1 and 0.7 cm, respectively, while the valley-to-peak ratios at each d max were 0.566, 0.412 and 0.293, respectively. Conclusion: Only the 2 mm TCR grid collimator had adequate dosimetric features compared to the conventional grid collimator and could be substituted.