US 5,233,990 A · Method and apparatus for diagnostic imaging in radiation therapy

Abstract

An apparatus for diagnostic and verification imaging in radiation therapy that consists of attachments for standard radiotherapy equipment comprising an x-ray tube and an x-ray detector placed on opposite sides of a patient along the main axis of the beam produced by the treatment unit. The detector is placed on a plane orthogonal to the axis of the treatment beam and between the beam source and the patient, while the x-ray tube is placed on the other side of the patient, coaxially with the treatment beam and facing the detector. As a result of this configuration, the radiographic view of the x-ray beam, as seen on the detector, is equivalent to the view produced on the same detector by the therapeutic beam, varied only by parallax deviations that can be corrected by geometrical calculations. Accordingly, x-ray exposures and real-time verification of the position of a patient can be obtained with the same unit used for treatment and without requiring movement of either patient or equipment. In addition, the apparatus enables a user to produce diagnostic images that can be used directly to manufacture shielding blocks in conventional shielding-block cutters.

Claims10

Dependent claims

An imaging apparatus in combination with conventional radiation therapy equipment consisting of a gantry having a high-energy radiation source capable of emitting a high-energy radiation beam and having shielding blocks, said gantry being disposed for irradiation of a stationary patient positioned on a gurney at a fixed distance from the high-energy radiation source, said apparatus comprising the following components:

a low-energy radiation source capable of emitting a low-energy radiation beam and mounted on a side of the gantry opposite to the high-energy radiation source, such that the beam from said low-energy radiation source is coaxial with the beam from the high-energy radiation source;
and
a radiation detector mounted between the high-energy radiation source and the low-energy radiation source so as to be between the high-energy radiation source and the patient's gurney, said detector being positioned so that it can be exposed to both the high-energy beam and the low-energy beam;
wherein said low-energy radiation source and said detector are used to irradiate the patient and obtain diagnostic images of the patient before treatment with the high-energy beam and to obtain verification images of the patient's position for proper therapeutic irradiation during treatment.

1 more element

A method for producing corrected verification images of anatomical portions of a patient being treated with conventional radiation therapy equipment consisting of a gantry having a high-energy radiation source capable of emitting a high-energy radiation beam along a high-energy beam axis and having shielding blocks, said gantry being disposed for irradiation of a stationary patient positioned on a gurney at a fixed distance from the high-energy radiation source, a simulator of the radiation therapy equipment, and a shielding-block cutter, said method comprising the following steps:

(a) using the simulator of the radiation therapy equipment to produce diagnostic images of the patient from a field of view equal to the field of view of the high-energy radiation source;
(b) delineating the anatomical portions of the patient requiring treatment on said diagnostic images;
(c) using said shielding-block cutter to adapt the shielding blocks so that the high-energy source has a field of view limited to an area corresponding to the anatomical portions delineated on said diagnostic images;
(d) providing a low-energy radiation source mounted on a side of the gantry opposite to the high-energy radiation source, said low-energy radiation source being capable of emitting of low-energy radiation beam along a low-energy beam axis coaxial with the axis of the beam from the high-energy radiation source;
(e) providing a radiation detector mounted between the high-energy radiation source and the patient's gurney, said detector being positioned so that it can be exposed to both the high-energy beam and the low-energy beam;
(f) irradiating the patient with said coaxial low-energy radiation source during treatment to form verification images on said radiation detector;
(g) performing parallax corrections to the verification images so produced in order to obtain corrected verification images that are directly comparable to the diagnostic images produced during step (a);
and
(h) comparing the corrected verification images with the diagnostic images during treatment to ensure that the anatomical portions of the patient being irradiated by high-energy radiation treatment correspond to the anatomical portions delineated on the diagnostic images.

6 more elements

A method for producing diagnostic and verification images of anatomical portions of a patient being treated with conventional radiation therapy equipment consisting of a gantry having a high-energy radiation source capable of emitting a high-energy radiation beam along a high-energy beam axis and having shielding blocks, said gantry being disposed for irradiation of a stationary patient positioned on a gurney at a fixed distance from the high-energy radiation source, and a shielding-block cutter, said method comprising the following steps:

(a) providing a low-energy radiation source mounted on a side of the gantry opposite to the high-energy radiation source, said low-energy radiation source being capable of emitting a low-energy radiation beam along a low-energy beam axis coaxial with the axis of the beam from the high-energy radiation source;
(b) providing a radiation detector mounted between the high-energy radiation source and the patient's gurney, said detector being positioned so that it can be exposed to both the high-energy beam and the low-energy beam;
(c) irradiating the patient with said coaxial low-energy radiation source to form diagnostic images of the patient on said radiation detector from a field of view corresponding to the low-energy radiation source;
(d) delineating the anatomical portions of the patient requiring treatment on said diagnostic images;
(e) using said shielding-block cutter to adapt the shielding blocks so that the high-energy source has a field of view limited to an area corresponding to the anatomical portions delineated on said diagnostic images;
(f) irradiating the patient with said coaxial low-energy radiation source during treatment to form corresponding verification images on said radiation detector;
and
(g) comparing the verification images with the diagnostic images during treatment to ensure that the anatomical portions of the patient being irradiated by high-energy radiation treatment correspond to the anatomical portions delineated on the diagnostic images.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for diagnostic imaging in radiation therapy

Life of this patent

Method and apparatus for diagnostic imaging in radiation therapy

Life of this patent

Abstract

Claims10