A method for use in a treatment planning process includes determining a modulability factor, and determining a treatment parameter using the modulability factor. A system for use in a treatment planning process includes a processor, wherein the processor is configured for determining a modulability factor, and determining a treatment parameter using the modulability factor. A method for use in a treatment planning process includes determining a visibility factor, and determining a treatment parameter using the visibility factor. A system for use in a treatment planning process includes a processor, wherein the processor is configured for determining a visibility factor, and determining a treatment parameter using the visibility factor.