Modulated electron radiation therapy(MERT)

which delivers conformal dose to shallow tumors and protects distal structures and surrounding tissues

but

the photon multileaf collimator(MLC) is no longer suitable for MERT.In this paper

the PENELOPE code is used to simulate an electron-specific MLC(EMLC) for the optimal choice of the material and geometry of leave.The results demonstrate that tungsten is more suitable for EMLC than lead

iron

copper;and 2 cm thickness is sufficient to resist most of the electrons with relatively less bremsstrahlung;leaf with straight end shape produces less dose penumbra and moreover the width of 1 cm is the most suitable choice for leaf width.