System and method for intensity modulated radiation therapy

#The present invention relates to radiation therapy, and more particularly, to a system and method for efficiently delivering radiation treatment.

#Radiation emitting devices are generally known and used, for instance, as radiation therapy devices for the treatment of patients. A radiation therapy device generally includes a gantry which can be swiveled around a horizontal axis of rotation in the course of a therapeutic treatment. A linear accelerator is located in the gantry for generating a high energy radiation beam for therapy. This high energy radiation beam can be an electron beam or photon (X-ray) beam. During treatment, this radiation beam is trained on one zone of a patient lying in the isocenter of the gantry rotation.

#To control the radiation emitted toward an object, a beam shielding device, such as a plate arrangement or a collimator, is typically provided in the trajectory of the radiation beam between the radiation source and the object. An example of a plate arrangement is a set of four plates that can be used to define an opening for the radiation beam. A collimator is a beam shielding device which could include multiple leaves, for example, a plurality of relatively thin plates or rods, typically arranged as opposing leaf pairs. The plates themselves are formed of a relatively dense and radiation impervious material and are generally independently positionable to delimit the radiation beam.

#A better understanding of the present invention can be obtained when the following detailed description is considered in conjunction with the following drawings in which:

#FIG. 1A and FIG. 1B illustrate an intensity map and footprint, respectively;

#FIG. 2A and FIG. 2B illustrate sequential IMRT;

#FIGS. 4-12 illustrate a system and method for intensity modulated radiation therapy according to embodiments of the present invention.

#Turning now to the drawings and, with particular attention to FIG. 4, a radiation treatment apparatus embodying the present invention is shown therein and generally identified by reference numeral 2. The radiation therapy apparatus 2 may be a Mevatron or Primus linear accelerator available from Siemens Medical Systems. The radiation treatment apparatus 2 includes a beam shielding device (not shown) within a treatment head 4, a control unit in a housing 9 and a treatment unit 200 according to the present invention. The radiation treatment device 2 includes a gantry 6 which can be swiveled around a horizontal axis of rotation 8 in the course of a therapeutic treatment. The treatment head 4 is fastened to a projection of the gantry 6. A linear accelerator is located in the gantry 6 to generate the high powered radiation required for the therapy. The axis of the radiation bundle emitted from the linear accelerator and the gantry 6 is designated by 10. Electron, photon or any other detectable radiation can be used for the therapy.

#During the treatment, the radiation beam is trained on a zone 12 of an object 13, for example, a patient who is to be treated and who lies at the isocenter of the gantry rotation. The rotational axis 8 of the gantry 6, the rotational axis 14 of a treatment table 16, and the beam axis 10 intersect in the isocenter.