What Is 3D-CRT?
Three-dimensional conformal radiation therapy (3D-CRT) uses sophisticated computers and computer assisted tomography scans (CT or CAT scans) to create detailed, three-dimensional representations of the tumor and surrounding organs. Tumors usually have an irregular shape. Three-dimensional conformal radiation therapy allows your radiation oncologist to customize the radiation beams exactly to the size and shape of your tumor.
The tools used to shape these radiation beams are multileaf collimators or blocks. Because the radiation beams are very precisely directed, nearby normal tissue receives less radiation exposure. This technique also permits the delivery of a larger dose of radiation to the cancer.