Estimation of the shielding ability of a tungsten functional paper for diagnostic x‐rays and gamma rays

Abstract

Tungsten functional paper (TFP) is a novel paper‐based radiation‐shielding material. We measured the shielding ability of TFP against x‐rays and gamma rays. The TFP was supplied in 0.3‐mm‐thick sheets that contained 80% tungsten powder and 20% cellulose (C6H10O5) by mass. In dose measurements for x‐rays (60, 80, 100, and 120 kVp), we measured doses after through 1, 2, 3, 5, 10, and 12 TFP sheets, as well as 0.3 and 0.5 mm of lead. In lead equivalence measurements, we measured doses after through 2 and 10 TFP sheets for x‐rays (100 and 150 kVp), and 0, 7, 10, 20, and 30 TFP sheets for gamma rays from cesium‐137 source (662 keV). And then, the lead equivalent thicknesses of TFP were determined by comparison with doses after through standard lead plates (purity >99.9%). Additionally, we evaluated uniformity of the transmitted dose by TFP with a computed radiography image plate for 50 kVp x‐rays. A single TFP sheet was found to have a shielding ability of 65%, 53%, 48%, and 46% for x‐rays (60, 80, 100, and 120 kVp), respectively. The lead equivalent thicknesses of two TFP sheets were 0.10 ± 0.02, 0.09 ± 0.02 mmPb, and of ten TFP sheets were 0.48 ± 0.02 and 0.51 ± 0.02 mmPb for 100 and 150 kVp x‐rays, respectively. The lead equivalent thicknesses of 7, 10, 20, and 30 sheets of TFP for gamma rays from cesium‐137 source were estimated as 0.28, 0.43, 0.91, and 1.50 mmPb with an error of ± 0.01 mm. One TFP sheet had nonuniformity, however, seven TFP sheets provided complete shielding for 50 kVp x‐rays. TFP has adequate radiation shielding ability for x‐rays and gamma rays within the energy range used in diagnostic imaging field.

Dosimetric evaluation of skin collimation with tungsten rubber for electron radiotherapy: A Monte Carlo study

“…6 However, an irradiation field shaped at the applicator has the disadvantage of a large penumbra compared with that shaped by a skin collimator. 7 In a previous study, we reported that shielding materials containing tungsten, such as tungsten functional paper (TFP) [7][8][9][10][11][12] and tungsten-containing rubber (TCR), [13][14][15] can provide sufficient radiation shielding against therapeutic electron beams and diagnostic xrays and γ-rays. In electron therapy, TCR offers the advantages of being nontoxic to the human body and being easy to shape the irradiation field.…”

Dosimetric characteristics of a thin bolus made with real time variable shape tungsten rubber for photon radiotherapy

“…We have developed tungsten-containing materials such as tungsten containing rubber [11][12][13] and tungsten functional paper [14][15][16][17][18][19], while those do not adhere well to the body surface. Real time variable shape rubber containing tungsten (STR; Hayakawa Rubber Co., Ltd. Hiroshima, Japan), which has a density of 7.3 g/cm 3 , can be manually formed to any shape by hand when warmed to approximately 60°C, and its shape maintains at body or room temperature [20][21][22][23].…”

A novel radiation-shielding undergarment using tungsten functional paper for patients with permanent prostate brachytherapy

“…The lead-based undergarments pose several issues, including the cost and the toxicity to the human body and the environment [ 10 ]. The European Union directive Restriction of the Use of Certain Hazardous Substances (in electrical and electronic equipment), prohibited the use of lead in electrical appliances after 1 July 2006.There is therefore a strong demand for lead-free product development in health-care and industrial applications [ 11 ].…”

“…It is easy to cut, fold and stick onto other materials. The TFP is lead-free, so is less harmful to the body than lead-containing materials and can be applied to a patient’s body surface [ 11 , 12 ]. It is also recyclable [ 10 ].…”