ABSTRACT
Objective To monitor the protective qualities of personal protective appliances and to ensure the health and safety of radiological working personnel.Methods The lead-equivalent thickness of personal protective appliances and materials was measured by means of standard lead slices.The lead equivalent thickness represents in terms of mm Pb.Results 77 pieces of products and samples were measured altogether.The results indicate that the specific lead equivalents of lead-rubber plates were between 0.20-0.39 mm Pb/mm for 37 pieces of lead-rubber plates and the values of 6 pieces of samples were less than 0.25 mm Pb/mm,which did not accord with the requirement of the relational standard.27 pieces of personal protection appliances were measured altogether.They were 12 pieces of protective clothes,4 pieces of protective headgears,5 pieces of protective neckpieces,4 pieces of protective gloves and 2 pieces of protective masks.13 pairs of lead-glass spectacles among them were measured altogether.The measured results for personal protective appliances and lead-glass spectacles showed that actually measured lead-equivalent were higher than the nominal lead-equivalent.Conclusions The protective qualities are reliable for personal protection materials and appliances to be made in home and imported abroad.But the protective qualities of interventional protection gloves should be improved and made them better.
ABSTRACT
Objective To explore the application of CT value in calculating the proton incident energy in proton treatment planning system. Methods Bethe-Block formula and the formula for calculating the proton range were analyzed to study the correlation of the range of proton beam ( 70-250 MeV ) between a variety of radiation equivalent material and water. Procedure of Monte Carlo SRIM2008 was used to verify the possibility of a constant proportional coefficient of range ( Ci ). The proportional coefficient ( Ci ) of range in radiation-equivalent material and the CT value were fitted by using Origin 8.0 software to study the functional relation of CT value and Ci. The actual range of proton was equivalent to a range of water and incident proton energy could be calculated. Results There was a constant range of Ci of proton beam (70-250 MeV) between a variety of radiation equivalent material and water. There was a functional relation between CT value and Ci ( r = 0.999). The actual range of proton in radiation equivalent material can be equivalent to a range of the water. Conclusions CT values and a range of proportional coefficient ( Ci ),and the actual required range of the tumor could be used to accurately calculate the water equivalent range,and the incident proton energy to the position of Bragg peak. A new exploration for using CT technology in proton treatment planning system could be obtained.