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.
A method and system for simulating and verifying a radiation therapy beam prior to treatment. The system also permits the accurate positioning of the beam with respect to the patient. The system utilizes a contour on a prescription image which defines the location and shape of a desired radiation treatment area to generate a transmissive projection which projects the exact field contour onto the patient during simulation. The patient can then be marked with this field contour prior to treatment in the simulation apparatus. With the patient placed in the treatment apparatus the accurate positioning of the patient can be achieved by aligning the patient's skin markings with a light projected through a multi-leaf collimator onto the skin. Furthermore, the correct functioning of the multi-leaf collimator can be verified in this manner since incorrect leaf positions will show up in the light projected onto the patient's skin. The transmissive projection means may comprise, in the preferred embodiment, a liquid crystal display projection device under control of a host computer storing a digitized image of the field contour.
A three terminal ionization chamber includes a first electrode coupled to a bias voltage source spaced apart from a second electrode coupled to ground. A third terminal is provided which is positioned between the first and second electrodes. Measurement circuitry may be coupled to the third terminal to measure charge indicative of the amount of radiation incident to the chamber.
Radiation is generated toward a patient. A radiographic region of the radiation covers a predetermined field-of-view. Both of a stereotactic radiation producing filter and a radiographic radiation producing filter are transported in such a way that the stereotactic radiation producing filter and the radiographic radiation producing filter sequentially intercept the beam axis between the patient and a generation position for the radiation. When the stereotactic radiation producing filter is located on the beam axis, it forms the radiation into radiation required for stereotactic radiosurgery. When the radiographic radiation producing filter is located on the beam axis, it forms the radiation into radiation required for radioscopy. Radiation present within the radiographic region is detected with employment of a radiation detecting unit positioned opposite to the generation position of the radiation with respect to the patient. The radiation is generated when the stereotactic radiation producing filter is located on the beam axis and the radiographic radiation producing filter is located on the beam axis.
A method and apparatus for monitoring a scanning beam of penetrating radiation, such as a scanning proton beam used to irradiate tissue. The position of the beam is tracked in real time by interposing a scintillator film between a source and an object of irradiation. An imaging detector, in optical communication with the scintillator, provides an output that is indicative of the position of the radiation and its variation with time. The accumulated dose over a scan may also be monitored.
The invention relates to a device for performing and verifying therapeutic radiation. An x-ray beam (4) is arranged across from a target volume (3) of the beam source (11) for the high-energy beam (1) in such a way that the beams (1, 4) run in essentially opposite directions (5, 6). The invention also relates to a computer program and a control method for operating said device. The inventive device makes it possible to exactly verify areas (16, 16', 16'') that are subjected to different levels of radiation, the entire anatomy of the target volume (3), and the surroundings thereof in addition to the contour of the therapy beam (1). The x-ray beam (4) detects the anatomy and position of the patient (21) within the range of the target volume (3) before the high-energy beam (1) is applied and the shape of the applied high-energy beam (1) is then detected and areas (16, 16', 16'') that are subjected to different levels of radiation as well as at least one partial segment of the target volume (3) during the emission breaks of the high-energy beam (1). The detected data is used for correcting the treatment plan.
