3D conformal radiation therapy is a radiation technique that uses radiation beams to conform the radiation being administered to a tumor.  In some ways, this conformal technique is similar to IMRT.  With conformal planning techniques, high doses of radiation may be given to a smaller target area, causing less damage to healthy tissue.  After a 3-dimensional image is taken of your tumor, the image is analyzed by a computer program that designs radiation beams to fit the exact measurements of the tumor.  During treatment, these directed beams are emitted from several different directions to maximize radiation exposure to the tumor alone.