Dosimetric evaluation of lead and tungsten eye shields in electron beam treatment

Enhanced epidermal dose caused by localized electron contamination from lead cutouts used in kilovoltage radiotherapy

“…3 Electron contamination from lead eye shields is also a known problem and commercial eye shields now have a protective low Z layer to soak up the contaminant dose. 4 An issue that has been largely neglected to date is the question of electron contamination from the custom lead cutouts that are placed directly on the patient's skin to define the treatment area, as shown in Fig. 1.…”

Evaluation of lens dose from anterior electron beams: comparison of Pinnacle and Gafchromic EBT3 film

“…In this case, a pencil shield is positioned on the surface of the patient or with an offset, hanging in air from the electron applicator, with a thickness of 1 cm and a variable diameter $\ge 1.0\hspace{0.17em}\text{cm}$. The second is the internal eye shield designed to reduce the dose to the entire extent of the eye when treating the eyelid or canthus 11 , 12 , 13 . Here, lead or tungsten hemispherical shields are placed directly onto the eye in treatments with low‐energy electrons (up to 9 MeV).…”

A novel approach in electron beam radiation therapy of lips carcinoma: A Monte Carlo study

“…10,11 In order to reduce the dose enhancement at the shield-tissue boarder, it is recommended to enclose the internal shield by a suitable thickness of a low atomic number material. 5,9,12,13 Recently, results of Monte Carlo (MC) simulations studying the dependences of the electron backscatter on the beam obliquity, energy, and thickness of Pb using the EGSnrcbased MC code have been published. 14 However, studies of lead electron backscatter are mostly focused on the shielding principles especially in commercial eye shields.…”

“…14 However, studies of lead electron backscatter are mostly focused on the shielding principles especially in commercial eye shields. 12,13,15 Chow et al studied the dosimetric dependence of the lead shielding for protection of the eye in electron radiotherapy with different energies. 14 Weaver et al carried out electron backscatter evaluation, due to using commercial eye shields in the electron beam treatment.…”