RADIOTHERAPY SYSTEM PROVIDED WITH A PROGRAM FOR THE CALCULATION OF THE INTENSITY OF AN ELECTRONS BEAM

摘要

A system for radiotherapy is described. The system includes an accelerator of an electron beam, an imaging apparatus, a control unit and a radiation dose sensor connected to the control unit equipped with a program configured to execute the steps: (i) setting a first intensity of the electron beam, according to a predefined image of a target zone, the intensity to be emitted in a first radiation; (ii) operating said accelerator to emit the first radiation being a fraction of the first intensity; (iii) detecting a real intensity during the first radiation by the radiation dose sensor; (iv) acquiring an image of the zone; (v) calculating an intermediate intensity according to the image acquired in the step (iv) and according to the real intensity; and (vi) comparing the first intensity with the intermediate intensity to calculate a final beam intensity for a subsequent second radiation

主权项

1. A system for radiotherapy provided with a program for calculation of intensity of an electron beam, the system comprising
a mobile electron accelerator, comprising a conveyor adapted to convey an electron beam with a presettable intensity on a zone of or internal to a patient, and forming a target radiotherapy, an image acquisition apparatus, configured to detect said zone, an integrated control unit, comprising a bidimensional or tridimensional image display and a computer, said computer being connected to said electron accelerator and to said image acquisition apparatus, and an active sensing device of a radiation dose deposited by said electron beam, placeable between a distal end of said conveyor and said zone, and connectable with said integrated control unit, said computer being provided with a program for calculation of an intensity of said electron beam by which said zone can be irradiated, said program performing the following steps when executed on said computer: (i) setting a first intensity of said electron beam, according to functioning and geometric characteristic parameters of said electron accelerator and/or calculated by Monte Carlo method, and according to at least one predefined image of said zone, said intensity being emitted by said electron accelerator in a first radiation; (ii) operating said electron accelerator to emit a first electron beam in said first radiation, corresponding to a fraction of said first intensity set in said step (i); (iii) detecting a real intensity of said first electron beam during said first radiation, by said radiation sensing device placed in correspondence of said zone; (iv) acquiring at least one image of said zone (Z) by said image acquisition apparatus; (v) calculating an intermediate intensity of said electron beam, according to said at least one image acquired in said step (iv) and according to said real intensity of said first electron beam detected in said step (iii); and (vi) comparing said first intensity of said step (i) with said intermediate intensity of said step (v) to calculate a final intensity of said electron beam, with which said zone can be irradiated in a second radiation following said first radiation, wherein calculation of said final intensity in said step (vi) is performed by equationf(i,j,k)=g(i,j,∑l=1kρlΔzkΔz)where ƒ(i, j, k) is a matrix representing said final intensity of said step (vi) that can be emitted in said second radiation, index k represents a depth of medium passed through, g(i, j, l) is an original matrix of data related to said first intensity set in said step (i), ρl is electronic density of the water and Δz is a voxel dimension of said at least one image acquired in said step (iv) along an axis of said electron beam, wherein i and j represent a starting point of a radiation path on said zone (Z).