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EP-3600549-B1 - SYSTEMS AND METHODS FOR DELIVERING RADIOTHERAPY

EP3600549B1EP 3600549 B1EP3600549 B1EP 3600549B1EP-3600549-B1

Inventors

  • SHENG, KE
  • BOUCHER, SALIME M.

Dates

Publication Date
20260506
Application Date
20180324

Claims (15)

  1. A radiotherapy system (100) comprising: a beam director (150) comprising a radiation source (158) configured to generate radiation for irradiating a patient, the beam director (150) having at least four degrees of freedom of movement; and a controller configured to operate the beam director to irradiate the patient in accordance with a radiation treatment plan, wherein the radiation treatment plan is generated and optimized based on a solution space that covers at least 60% of a 4π solid angle about the patient to define a plurality of beam orientations that are each different, and wherein the radiation treatment plan is generated based on the solution space being determined by the at least four degrees of freedom of movement of the beam director.
  2. The radiotherapy system (100) of claim 1, wherein the radiation source (158) comprises a linear accelerator.
  3. The radiotherapy system (100) of claim 1, wherein the radiotherapy system is configured to move the radiation source to each location of the solution space.
  4. The radiotherapy system (100) of claim 3, wherein the beam director (150) further comprises an articulated arm (154) extending from the base (152) and mechanically linked to the base (152).
  5. The radiotherapy system (100) of claim 4, wherein the articulated arm (154) comprises at least two joints configured to provide the beam director (150) the at least four degrees of freedom of movement.
  6. The radiotherapy system (100) of claim 4, wherein the beam director (150) further comprises a treatment head (156) that houses the radiation source (158), the treatment head (156) being mechanically linked to the articulated arm (154).
  7. The radiotherapy system (100) of claim 6, wherein the treatment head (156) further comprises a collimator (160) positioned adjacent to an output of the radiation source (158).
  8. The radiotherapy system (100) of claim 1, wherein the solution space covers at least 90% of a 4π solid angle about the patient.
  9. The radiotherapy system (100) of claim 1, wherein the controller is further configured to operate the beam director (150) to irradiate the patient from directions posterior in relation to the patient.
  10. The radiotherapy system (100) of claim 1, wherein the controller is further configured to operate the beam director (150) to irradiate the patient and deliver the radiation treatment plan while the patient is stationary.
  11. A computer implemented method for controlling a radiation therapy system (100) according claim 1, the method comprising; generating, based on a dose prescription, a radiation treatment plan optimized from a solution space that covers at least 60% of a 4π solid angle about the patient to define a plurality of beam orientations that are each different, the radiation treatment plan determined by a beam director (150) of a radiotherapy system (100) having at least four degrees of freedom of movement.
  12. The method of claim 11, wherein the method further comprises executing an optimization algorithm to generate the radiation treatment plan, the optimization algorithm configured to select beam configurations based on the solution space determined by the beam director (150).
  13. The method of claim 12, wherein the method further comprises executing the optimization algorithm to optimize a dosimetry and an efficiency of delivering beams in the radiation treatment plan.
  14. The method of claim 11, wherein the solution space covers at least 90% of the 4π solid angle about the patient.
  15. The method of claim 11, wherein the method further comprises generating the radiation treatment plan using a variable source-to-axis distance ("SAD").

Description

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH This invention was made with government support under R44CA183390, and R43CA183390 awarded by the National Institutes of Health. The government has certain rights in this invention. BACKGROUND The present disclosure relates, in general, to external beam radiation therapy systems and methods, and more particularly to external beam radiation therapy systems and methods having a beam director with at least four degrees of freedom. Conventional external beam radiation therapy, also referred to as "teletherapy," is commonly administered by directing beams of ionizing radiation produced by a linear accelerator ("LINAC") toward a defined target volume in a patient. Radiation dose with a specific profile can be built up in the target by shaping the beams into treatment fields using collimators and other devices, and irradiating the patient for certain amounts of time using the shaped beams. In preparing a radiation treatment plan, planning images, such as computed tomography ("CT"), are used to select beam configuration that optimize therapeutic effects and reduce radiation-induced side effects. In addition, medical imaging can also be used concurrently with the delivery of radiation therapy in a technique called image-guided radiation therapy ("IGRT"). Using positional information from the images to supplement the radiation treatment plan, IGRT can improve the accuracy of the delivered radiation. This allows for radiation dose imparted to targeted regions to be escalated to achieve better outcomes, with reduced risk to healthy tissues. Intensity modulated radiation therapy ("IMRT") is an external beam radiation therapy technique that utilizes computer planning software to produce a three-dimensional radiation dose map specific to locations, shapes and motion characteristics target and non-target structures in a patient. To do so, IMRT utilizes multiple beams that may be independently controlled in intensity and energy. Specifically, each beam includes a number of sub-beams or beamlets whose individual intensity can be varied to modulate the beam. Using this technique, specific regions within a targeted tumor, as well as other target and non-target structures in the patient's anatomy, can receive different radiation dose intensities. The quality of radiation therapy delivered to a patient depends at least in part upon the spatial arrangement and intensity modulation of beams. When beam orientations are optimized, the quality of therapy can be significantly improved. However, optimized plans often require non-coplanar beams, which can be difficult to deliver using conventional LINACs. This is because these machines utilize gantries that have only one degree of rotational freedom. To address this, treatment plans often include patient couch repositioning. However, coordinating gantry and couch motion, along with imaging, can complicate treatment and introduce the potential for significant problems. For example, collisions, patient movement and difficulties with monitoring of the patient using imaging, can interfere with treatment and lead to possible equipment damage and patient injury. In addition, mechanical constraints on couch and gantry movements only provide a limited number of additional beam orientations. In many cases, such limited beam configurations can prevent clinicians from reaching the optimal plan quality and therefore the best treatment option. Therefore, there is a need for improved systems and methods for delivering radiotherapy treatment. US 2007/0071168 A1 relates to an apparatus and method for optimizing a workspace of a radiation treatment delivery system. US 2010/0104068 A1 describes a method and apparatus for radiation treatment planning. SUMMARY A radiotherapy system and method for delivering radiotherapy are provided. Features and advantages of the present disclosures may be appreciated from descriptions below. In one aspect of the present disclosure, a radiotherapy system is provided. The radiotherapy system includes beam director comprising a radiation source configured to generate radiation for irradiating a patient, the beam director having at least four degrees of freedom of movement. The radiotherapy system also includes a controller configured to operate the beam director to irradiate the patient in accordance with a radiation treatment plan, wherein the radiation treatment plan is generated based on a solution space determined by the at least four degrees of freedom of movement of the beam director. In another aspect of the present disclosure, a method for delivering a radiation treatment plan to a patient using a radiotherapy system is provided. The method includes generating, based on a dose prescription, a radiation treatment plan optimized from a solution space determined by a beam director of a radiotherapy system having at least four degrees of freedom of movement. The method also includes receiving imaging information acquired