Corrección automática del posicionamiento del paciente durante el tratamiento de radioterapia

Abstract

In the usual clinical procedure, for the application of a radiotherapy treatment, a dosimetry planning is previously performed from a x-ray volumetric scanning (Computed Tomography), placing on the patient several fiduciary marks, that will serve as external reference. In the treatment stage, the problem is to place the patient correctly in the accelerator so that the radiotherapy treatment precisely corresponds to the planned doses. This verification is achieved by comparing a Digitally Reconstructed Radiography from planning stage and a portal image obtained from the accelerator. Then the couch and the patient are moved longitudinally and transversally, using the fiduciary marks on the patient skin as a reference. The paper proposes an automatic method, based on image registration techniques, to accurately compute the couch movement required to locate the patient in the planned position. This method shows a perfect matching with the displacements estimated by the facultative during the corresponding treatments.