Deutsches Krebsforschungszentrum

Deutsches Krebsforschungszentrum Stiftung Des Oeffentlichen Rechts

Deutsches Krebsforschungszentrum Stiftung Des Offentlichen Rechts

Precisis Ag

Gernot Echner

Otto Pastyr

Wolfgang Schlegel

Steffen Seeber

Klaus Schewiola

Karl-Heinz Hover

Martin Baumann

Walter Ganter

Stefan Ueltzhöffer

Jurgen Richter

Simone Barthold

Karl-Heinz H&ouml;ver

Armin Runz

Günther Hartmann

The invention relates to a leaf assembly () for a multi-leaf collimator, comprising a leaf frame () and a plurality of leaves () for shielding beams () from a selected area, wherein the leaves () are arranged sideways and adjacently in the leaf frame () for shielding beams () being emitted from a radiation source () located above the assembly (), wherein each leaf () is mounted in the leaf frame () displaceably in an adjusting direction () being oriented perpendicularly related to said beams (), and wherein the leaf frame () provides a linear guidance () for each leaf () within the adjusting direction (), being designed in a such a way that the leaf frame () is adapted to allow for lateral movement of the leaves () superposing said linear guidance (), thus allowing mutual abutting of the leaves (). Furthermore, the invention relates to a multi-leaf collimator comprising two leaf assemblies () according to the invention, wherein the assemblies () are arranged to face each other within the adjusting direction (). The invention is based on the objective of designing a leaf assembly () for a multi-leaf collimator and a multi-leaf collimator in such a way that the occurrence of leak-age radiation may be diminished.

Leaf assembly for a multi-leaf collimator and multi-leaf collimator

The invention relates to a leaf module () for a multi-leaf collimator (), comprising a leaf unit () and a leaf drive unit (), wherein the leaf unit () comprises a leaf () for shielding beams from a selected area, and the leaf unit () is mounted displaceably in an adjusting direction (), wherein the leaf drive unit () is designed to displace the leaf unit () linearly in the adjusting direction (), and wherein the leaf drive unit () comprises at least one drive mechanism (), being designed in such a way that the drive mechanism () operates based on pneumatic actuation. Furthermore, the invention relates to a multi-leaf collimator () comprising a plurality of leaf modules () according to the invention. The invention is based on the objective of designing a leaf module () and a multi-leaf collimator () as compactly as possible, while achieving a simple, reliable and variable adjustability of the leaf unit (). The invention is regarded to be particularly suitable for implementation in Cobalt-60 or mid- to low-end linac radiotherapy apparatuses.

Leaf module for a multi-leaf collimator and multi-leaf collimator

A leaf module for a multi-leaf collimator comprises a leaf unit and a leaf drive unit. The leaf unit comprises a leaf for shielding beams from a selected area. The leaf unit is mounted displaceably in an adjusting direction with relation to the leaf drive unit. The leaf drive unit is designed to displace the leaf unit linearly in the adjusting direction. The leaf drive unit comprises at least one drive mechanism which operates based on piezoelectric actuation, being designed such that the leaf drive unit thoroughly encloses the leaf unit within a plane being oriented substantially perpendicularly related to the adjusting direction. The multi-leaf collimator can comprise a plurality of leaf modules while being shaped as compact as possible. Both precise and stable adjustability of the leaf unit is achieved with the leaf module.

A multi-leaf collimator includes leaf drives and two sets of displaceable leaves arranged side by side and facing each other to impress a high-energy beam with the shape of an irregularly formed treatment object. Each of the leaves assumes a position oriented along the shape of the treatment object by means of a leaf drive and each are equipped with a gear rod-like drive engagement in the direction of the displacement. A leaf-side pivotable gear segment is located, together with a motor-side gear segment, on a segment disk that engages with the gear rod-like drive engagement. A pinion drivable by a motor engages with the motor-side gear segment. The segment discs are arranged side by side for each set of leaves as a package on one axis. The motor-side gear segments of two segment disks located next to each other are staggered so that they will not abut each other.

Multi-leaf collimator with leaf drive

The invention relates to a method and device for operating collimator () for limiting a beam of high-energy radiation () which, starting from an essentially point-shaped radiation source (), is directed onto an object () to be treated and which is used especially for stereotactic, conformal radiation therapy of tumors, wherein the collimator () has an iris diaphragm () as a beam-limiting means. For such a collimator (), a high degree of shielding for minimal overall height and with a variable opening size of the diaphragm opening () is achieved, in that the iris diaphragm () has at least three diaphragm leaves (, or, or, or) which have touching side surfaces () enclosing the same angle (&#x3b1;), wherein the diaphragm leaves (, or, or, or) open up a beam-limiting opening () such that a sliding movement () along the side surfaces () takes place by a number of diaphragm leaves (, or, or, or) which is reduced by at most one.

Method and device for defining a beam of high-energy rays

An irradiation device for radiation treatment and a collimator () are used to define a beam of high-energy rays () with beam limitation by means of an iris diaphragm () having adjusting elements (), and a mechanism that is used to direct the beams (') limited by the collimator () to the object to be treated () from all sides, wherein the parameters for direction, surface area, intensity and time of irradiation can be specified with the help of a control mechanism. An exact three-dimensional irradiation profile is produced, while keeping the costs and efforts regarding mechanical engineering, computation and irradiation time low. This is achieved by using at least one further iris diaphragm () located in coaxial alignment in the optical path, whereby the leaves () of the iris diaphragms () are arranged in a staggered manner and in a rotational sense around their axis (), so that the beam limited by the collimator () has the cross-section of a polygon (), the number of corners of which complies with the number of the leaves of all iris diaphragms (), so that the leaves () allow for linear adjustment movements (), the control mechanism being suitable to enable the irradiation of an irregular space through the overlaying and adjoining of many irradiated spaces ().

Irradiation device and collimator

The invention relates to a collimator () for defining a beam of energetic rays () which is emitted from an essentially punctiform radiation source () and is oriented onto an object () to be treated. The collimator is especially used for the stereotactic conformation radiotherapy of tumors. The collimator () is embodied in such a way that an irregular object () can be scanned by rays (') which are defined by an opening in the collimator. The invention also relates to a program for controlling the collimator. In order to define the contours (&#x2033;) of the objects () to be irradiated in a simple but highly accurate manner, especially with a precise definition of the irradiation fields, the collimator comprises a plurality of different sized openings (&#x2033;). One of the openings (&#x2033;) can be selectively displaced in a polydirectional manner on a strip () having a spherical surface, and the central axis () thereof is oriented towards the radiation source (). The other collimator openings (&#x2033;) are shielded form the rays (). A control system () acts on the drives () of a drive device () in such a way that large openings (&#x2032;) are used to scan large irradiation surfaces () of the object to be treated (), and small openings (&#x2033;) are used for precise definition at the edge of the irradiation surfaces () of the object to be treated (), especially in the event of irregular contours (&#x2033;).

Collimator for high-energy radiation and program for controlling said collimator

The invention relates to a collimator ( ) for limiting a bundle of high-energy rays ( ), which is emitted by a substantially point-like radiation source ( ) and directed towards a treatment object ( ) and used in particular for the stereotactic conformation radiotherapy of tumors. According to the invention the collimator ( ) comprises a plurality of diaphragm leaves ( &prime;) which are arranged opposite each other and which are made of a radiation-absorbing material and which, by means of drive mechanisms, can be moved into the optical path in such a way that the contours and/or exposure period of said optical path can be freely defined, the front edges ( &prime;) of the diaphragm leaves ( &prime;) being parallel to the optical path at all times. Avoiding penumbral shadows with this kind of collimator ( ) is made considerably easier if the diaphragm leaves ( &prime;) consists of a rear partial element ( &prime;) which can be linearly displaced and a front partial element ( &prime;) which is hinged to same. Drive means adjust the front partial element ( &prime;) in accordance with the prevailing position of the rear partial element ( &prime;) in such a way that the front edges ( &prime;) are parallel to the optical path at all times.

Collimator for limiting a bundle of high-energy rays

A contour collimator for radiation therapy has a plurality of diaphragm elements that are movable with respect to each other by means of drive units. The diaphragm elements of the invention are supported only on the side near the drive units for ease of movement. This allows larger contour collimators to be constructed having relatively heavy diaphragm elements while retaining relatively small motors.

Contour collimator for use in radiotherapy

The invention relates to a displacement-detecting element ( ) comprising a measuring resistance ( ), voltage source ( ) and a displacement-dependent voltage pick off ( ). The measuring resistance ( ) is embodied in the form of a strip. The length of the resistor ( ) corresponds to at least the maximal length of displacement ( ) of the component to be detected. The invention also relates to a multileaf collimator ( ) having such a displacement-detecting element ( ). The aim of the invention is to produce a displacement-detecting element (a) for detecting the position of the leaves ( ) in a multileaf collimator ( ) in a precise and faultless manner. The displacement detecting element ( ) is designed for detecting the displacement ( &prime;) of the leaves ( ) in a multileaf collimator ( ) in the following manner: the measuring resistance ( ) or the voltage pick off point ( ) are connected in a rigid manner to the leaves ( ) in order to detect the displacement and another functioning element ( or ) is arranged in a fixed manner. At least one of these functioning elements ( ) is disposed in an area ( &Prime;) of the leaves ( ), which is not exposed to main radiation ( ).

Displacement detecting element

The radiation system has several radiation sources aimed toward a central point. These radiation sources are on arc element that pivots on an axis. The center can hence be irradiated from different sides. The radiation sources preferably have irregularly adjustable diaphragms. The system is suitable for irradiating any part of the human body. It is easy to manufacture and simple to used.

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Wiesenbach, Germany

Gernot Echner