Private Sub RadGridView1_CreateCell(sender As Object, e As GridViewCreateCellEventArgs)
    If e.CellType Is GetType(GridCommandCellElement) Then
        e.CellElement = New MyGridCommandCellElement(e.Column, e.Row)
    End If
End Sub

Public Class MyGridCommandCellElement
    Inherits GridCommandCellElement
    Public Sub New(column As GridViewColumn, row As GridRowElement)
        MyBase.New(column, row)
    End Sub
    Public Overrides Sub Detach()
        If Me.CommandButton IsNot Nothing Then
            Me.CommandButton.Image = Nothing
        End If
    End Sub
End Class