1. A method of preplanning for guided medical procedures, comprising the steps of: obtaining a first 3D diagnostic dataset for a region of interest of a subject, said first dataset being a non-stereotactic dataset, said first dataset providing sufficient contrast to identify target tissue in said region of interest; developing a treatment preplan to treat or remove said target tissue based on said first dataset exclusive of any stereotactic data, said treatment preplan including placement locations for a plurality of initial radiation beams and their respective dose intensities; obtaining a second 3D dataset for said region of interest, said second dataset being a stereotactic dataset; registering said first dataset to said second dataset, wherein a registered dataset, comprising a transformation matrix for mapping said first dataset into said second dataset, is created, and transforming said treatment preplan using said transformation matrix for transferring said preplan from said first dataset into a treatment plan based on said second dataset to generate a stereotactic treatment plan comprising a plurality of radiation treatment beams delivering said respective dose intensities and having respective placement positions based on said registered dataset to treat or remove said target tissue.