3-Dimensional Conformal Radiotherapy
3-Dimensional Conformal Radiotherapy is a form of radiation therapy where the fields used are designed so that the radiation dose is mostly delivered to the tumor, while the surrounding tissues receive little to no radiation dose. This type of conformal radiation therapy attempts to deliver a tumorcidal dose to the tumor while minimizing the damage to the surrounding healthy tissues.
In order to achieve this goal, the radiation beams are blocked by the MLC so that the projection of the tumor volume onto the plane of the radiation field conforms to the field aperture. It is important to note that the intensity of the open part of the radiation portal in 3D conformal therapy is uniform.
The development of such a 3-dimensional treatment plan requires 3-dimensional information about the patient's body. This information is supplied by the CT-simulations process. Once the physician has outlines the volumes of interest on the 3D CT scans, a fully 3-dimensional, conformal radiation therapy plan can be developed.