EP-4299115-B1 - RADIOTHERAPY DEVICE COMPRISING A TILTING MECHANISM

EP4299115B1EP 4299115 B1EP4299115 B1EP 4299115B1EP-4299115-B1

Inventors

WIBERG, KRISTIAN
CARLANDER, Erik
NYMAN, MARKUS
ALEXIS, HENRIK

Dates

Publication Date: 20260513
Application Date: 20230628

Claims (13)

A radiotherapy device comprising a tilting apparatus for tilting a source of radiation, the tilting apparatus comprising: a plurality of guide rails comprising a first and a second guide rail, wherein the first and second guide rails are linear; a plurality of carriages comprising a first carriage and a second carriage, the first carriage being translatable along the first guide rail and the second carriage being translatable along the second guide rail; and a support structure for supporting the source of radiation, wherein the support structure is rotatably coupled to each of the first and second carriages; wherein the first and second guide rails oblique with respect to one another and are angled with respect to one another such that translation of the carriages along the guide rails causes tilting of the support structure.
The radiotherapy device of claim 1, further comprising a gantry configured to rotate the tilting apparatus about a gantry rotation axis.
The radiotherapy device of claim 2, wherein the support structure is tiltable between a first and a second configuration, wherein, in the first configuration, the source of radiation is positioned to emit radiation along a first beam axis, and in the second configuration the source of radiation is positioned to emit radiation along a second beam axis.
The radiotherapy device of claim 3, wherein the first and second beam axes meet at a common isocentre.
The radiotherapy device of claim 3 or claim 4, wherein the first beam axis is orthogonal to the gantry rotation axis, and the second beam axis meets the gantry rotation axis at an acute angle.
The radiotherapy device of any preceding claim, further comprising the source of radiation coupled to the support structure.
The radiotherapy device of any preceding claim, wherein the guide rails are fixedly coupled to the gantry to rotate therewith.
The radiotherapy device of any preceding claim, further comprising an actuator configured to translate the carriages along the guide rails, optionally wherein the actuator is a linear actuator coupled to at least one of the first and second carriage.
The radiotherapy device of any preceding claim, the plurality of guide rails further comprising a third and a fourth guide rail; the plurality of carriages further comprising a third and a fourth carriage, the third carriage being translatable along the third guide rail and the fourth carriage being translatable along the fourth guide rail; wherein the support structure is further rotatably coupled to each of the third and fourth carriages; and wherein the first and third guide rail are substantially parallel with respect to one another, and the second and fourth guide rail are substantially parallel with respect to one another.
The radiotherapy device of claim 9, wherein the first and second guide rail are positioned on a first side of the support structure, and the third and fourth guide rail are positioned on a second, opposite side of the support structure.
The radiotherapy device of any of claims 2 to 10, wherein the first carriage is rotationally coupled to the support structure to define a first rotational axis and the second carriage is rotationally coupled to the support structure to define a second rotational axis, and wherein translation of the carriages along the guide rails changes a relative distance, in a radial direction, between the first and second rotational axes, wherein the radial direction is perpendicular to the gantry rotational axis.
A tilting apparatus for tilting a source of radiation in the radiotherapy device of any preceding claim, the tilting apparatus comprising: a plurality of guide rails comprising a first and a second guide rail, wherein the first and second guide rails are linear; a plurality of carriages comprising a first carriage and a second carriage, the first carriage being translatable along the first guide rail and the second carriage being translatable along the second guide rail; and a support structure for supporting the source of radiation, wherein the support structure is rotatably coupled to each of the first and second carriages; wherein the first and second guide rails are oblique with respect to one another and are angled with respect to one another such that translation of the carriages along the guide rails causes tilting of the support structure.
A method of tilting a source of radiation of a radiotherapy device according to any of claim 1 to 11, the device comprising the source of radiation and drive means comprising one or more linear actuators configured to translate the carriages along the guide rails to cause tilting of the support structure, the method comprising: while the device is in a coplanar configuration, driving the one or more linear actuators to translate the carriages along the guide rails in a first direction to tilt the source of radiation into a non-coplanar configuration; and while the device is in the non-coplanar configuration, driving the one or more linear actuators to translate the carriages along the guide rails in a second, opposite direction to thereby bring the radiation source back to the coplanar configuration.

Description

This disclosure relates to a radiotherapy device, and in particular to a radiotherapy device comprising a tilting apparatus for tilting a source of radiation. Background Radiotherapy can be described as the use of ionising radiation, such as X-rays, to treat a human or animal body. Radiotherapy is commonly used to treat tumours within the body of a patient or subject. In such treatments, ionising radiation is used to irradiate, and thus destroy or damage, cells which form part of the tumour. A radiotherapy device typically comprises a gantry which supports a beam generation system, or other source of radiation, which is rotatable around a patient. For example, for a linear accelerator (linac) device, the beam generation system may comprise a source of radio frequency energy, a source of electrons, an accelerating waveguide, a beam shaping apparatus, etc. When delivering a beam of radiation to a tumour or other target region of a patient, it is desirable to deliver the radiation from multiple angles to minimise the effect of the radiation on healthy tissue. One way of achieving this is to rotate the radiation source about the patient, for example about a longitudinal axis of the patient, such that radiation can be delivered to the target region from many angles in a plane perpendicular to the patient's longitudinal axis. Treatments that employ rotation of the radiation source solely in this manner, i.e. in a single geometric plane with respect to the patient, are known as 'coplanar'. Additional beam angles may be achieved by tilting the radiation source outside of the plane perpendicular to the patient's longitudinal axis, such that radiation is delivered at an oblique angle relative to the patient's longitudinal axis. Thus, radiation can be delivered from more than one geometric plane with respect to the patient. This increases the number of angles at which radiation can be delivered to the patient, thereby minimising the effect on healthy tissue. Such approaches are sometimes referred to as "non-coplanar". An exemplary radiotherapy system comprising a mechanism configured to tilt a source of radiation is described in publication US 2012/189102 A1. However, many challenges present themselves when designing and constructing a radiotherapy device capable of both coplanar and non-coplanar treatment. In each of the coplanar and non-coplanar angles, the therapeutic radiation beam should be directed toward a single isocentre to meet safety and regularly requirements. Prior designs for devices capable of delivering both coplanar and non-coplanar treatment are typically extremely large and heavy. Both the cost and complexity of these known prior systems is high. Complex counterweight systems may be required. Some prior designs have made use of a large curved rail along which the radiation source may be moved outside the plane of the gantry in order to deliver radiation from non-coplanar angles, however a disadvantage of this approach is that such designs require a significant increase in the height of the device in comparison with traditional coplanar devices, and therefore such devices do not make optimal use of available space, and may be too large to fit into a hospital's radiotherapy bunker. The present invention seeks to address these and other disadvantages encountered in the prior art. Summary An invention is set out in the claims. A radiotherapy device is provided comprising a tilting apparatus for tilting a source of radiation. The tilting apparatus comprises a plurality of guide rails comprising a first and second guide rail. The first and second guide rails are linear. The tilting apparatus further comprises a plurality of carriages comprising a first carriage and a second carriage, the first carriage being translatable along the first guide rail and the second carriage being translatable along the second guide rail. The apparatus further comprises a support structure for supporting the source of radiation, wherein the support structure is rotatably coupled to each of the first and second carriages. The first and second guide rails are oblique with respect to one another and are angled with respect to one another such that translation of the carriages along the guide rails causes tilting of the support structure. In some embodiments the device further comprises a gantry configured to rotate the tilting apparatus about a gantry rotation axis. In some embodiments the support structure is tiltable between a first and a second configuration, wherein, in the first configuration, the source of radiation is positioned to emit radiation along a first beam axis, and in the second configuration the source of radiation is positioned to emit radiation along a second beam axis. In some embodiments the first and second beam axes meet at a common isocentre. In some embodiments the first beam axis is orthogonal to the gantry rotation axis, and the second beam axis meets the gantry rotation axis at an acute angle. In som