Method and system for stereotactic intensity-modulated arc therapy

Abstract

A method of irradiating a target in a patient comprising directing a beam of radiation from an external source of radiation 24 at the target in the patient from numerous directions in a broad solid angle by longitudinally rotating the external source of radiation 24 around a central axis and simultaneously or sequentially, in either order, latitudinally rotating the external source of radiation 24; a globe gantry 21 comprising (i) a front opening ring 22 with its origin on the central axis of the globe gantry 21, (ii) at least one arc-shaped, gantry support arm 23, which has a front end and a rear end and is part of a circle, (iii) an external source of radiation 24, which is mounted on at least one arc-shaped, gantry support arm 23 and is movable along the gantry support arm to vary the latitude of the beam angle, (iv) a rear rotational axle 25 with an axis along the central axis of the globe gantry 21, (v) a support base 27, and (vi) a rear housing 26 comprising a source of power, mechanisms for moving components of the globe gantry 21, and controllers for controlling the movement of the components of the globe gantry 21 and the irradiation of the target in the patient; a system 20 comprising the globe gantry 21; and a method of irradiating a target in a patient using the system.

1 . A method of irradiating a target in a patient, which method comprises directing a beam of radiation from an external source of radiation at the target in the patient from numerous directions in a broad solid angle by longitudinally rotating the external source of radiation around a common isocenter concentrically and simultaneously or sequentially, in either order, latitudinally rotating the external source of radiation, whereupon the beam of radiation irradiates the target in the patient. 
     
     
         2 . The method of  claim 1 , wherein the intensity of the beam of radiation, the shape of the aperture of the beam of radiation, or both the intensity and the shape of the aperture of the beam of radiation is/are varied during irradiation throughout different points of longitudinal and/or latitudinal rotation or during maintenance of the external source of radiation at a single, static location. 
     
     
         3 . The method of  claim 1 , wherein the speed of longitudinal rotation of the external source of radiation, the speed of latitudinal rotation of the external source of radiation, or both the speed of longitudinal rotation and the speed of latitudinal rotation of the external source of radiation is/are varied. 
     
     
         4 . The method of  claim 1 , which further comprises continuously or discontinuously moving the patient during irradiation. 
     
     
         5 . A globe gantry for longitudinally and latitudinally rotating at least one external source of radiation concentrically around an isocenter placed in a target to be irradiated, which globe gantry has a central axis intersecting the isocenter and which comprises the following components:
 (i) a front opening ring with its origin on the central axis of the globe gantry,   (ii) at least one arc-shaped, gantry support arm, which has a front end and a rear end and is part of a circle,   (iii) an external source of radiation, which is mounted on at least one arc-shaped, gantry support arm and can move along the arc-shaped, gantry support arm to make latitudinal rotation about the isocenter.   (iv) optionally, a beam stopper, which is mounted on at least one arc-shaped, gantry support arm on the opposite side of the globe gantry from the external source of radiation,   (v) a rear rotational axle with an axis along the central axis of the globe gantry,   (vi) a support base, and   (vii) a rear housing comprising a source of power, mechanisms for moving components of the globe gantry, and controllers for controlling the movement of the components of the globe gantry and the irradiation of the target in the patient, wherein the front opening ring is attached to the front end of the at least one arc-shaped, gantry support arm, wherein the rear rotational axle is attached to the rear end of the at least one arc-shaped, gantry support arm, wherein the front opening ring and the rear rotational axle are supported by the support base and the rear housing, and wherein the front opening ring and the rear rotational axle can rotate around the central axis causing the external source of radiation to rotate longitudinally.   
     
     
         6 . The globe gantry of  claim 5 , wherein the external source of radiation is a linear accelerator or a radioisotope teletherapy device. 
     
     
         7 . The globe gantry of  claim 5 , wherein the external source of radiation can move along the length of the at least one arc-shaped, gantry support arm on which it is mounted at a variable speed. 
     
     
         8 . The globe gantry of  claim 5 , wherein the external source of radiation is fixed on at least one arc-shaped, gantry support arm, and the arc-shaped, gantry support arm and the rear rotational axle are translated to cause the external source of radiation to rotate latitudinally at variable speed. 
     
     
         9 . The globe gantry of  claim 5 , the orientation of the central axis of which can be changed from horizontal to substantially vertical or vertical, in which case the rear housing can rotate longitudinally and pivot between horizontal and vertical positions along with the globe gantry. 
     
     
         10 . The globe gantry of  claim 5 , which comprises at least two arc-shaped, gantry support arms, which are separated by longitudinal angles of 180° or at least two pairs of adjacent arc-shaped, gantry support arms, which pairs are separated by longitudinal angles of 180°. 
     
     
         11 . A system for irradiating a target in a patient, which system comprises the following components:
 (i) the globe gantry of  claim 5 ,   (ii) a patient platform, which is positioned along the central axis of the globe gantry and which comprises a first end and a second end,   (iii) a patient platform support, which supports the patient platform, and optionally,   (iv) a shield, which separates the patient from the rest of the system.   
     
     
         12 . The system of  claim 11 , wherein the patient platform can be independently moved in either direction along the length of the patient platform or z-dimension, in either direction along the width of the patient platform or x-dimension, and/or in either direction above or below the patient platform or y-direction, and such movements are in synchrony with the longitudinal and latitudinal rotations of the external source of radiation. 
     
     
         13 . The system of  claim 11 , the components of which further comprise:
 (v) at least two straight support beams,   (vi) an x-ray tube, and   (vii) an x-ray detector array,   wherein the x-ray tube is mounted on at least one straight support beam on one side of the globe gantry, wherein the x-ray detector array is mounted on at least one straight support beam on the opposite side of the globe gantry from the x-ray tube, and can move along the lengths of the at least two straight support beams to which they are mounted, and   wherein the at least two straight support beams are parallel with the central axis of the globe gantry and are supported at the front end by a bearing mounted on the front ring of the globe gantry and at the rear end by a bearing that is coaxial with, but separate from, the rear rotational axle of the globe gantry, so as to rotate independently of the rotation of the globe gantry.   
     
     
         14 . The system of  claim 13 , wherein the x-ray detector array is one-dimensional or multi-dimensional. 
     
     
         15 . The system of  claim 13 , the components of which further comprise (viii) a computed tomography (CT) imaging system, a magnetic resonance imaging (MRI) system, or a positron emission tomography (PET)/computed tomography (CT) imaging system attached to or positioned adjacent to the front opening ring of the globe gantry, coaxially or non-coaxially, wherein the CT imaging system, the MRI system, or the PET/CT imaging system can provide onboard imaging guidance. 
     
     
         16 . A method of irradiating a target in a patient under imaging guidance using the system of  claim 15 , which method comprises:
 i) imaging the patient in the treatment position, using the x-ray tube and x-ray detector complex or using the CT, MRI, or PET/CT imaging system;   ii) developing a treatment plan to deliver a focal radiation dose by directing intensity-modulated beams of radiation from the external source of radiation at the target in the patient in a treatment position from numerous directions in a broad solid angle by longitudinally rotating the external source of radiation around a central axis and simultaneously or sequentially, in either order, latitudinally rotating the external source of radiation, while continuously or discontinuously moving the patient;   iii) delivering the treatment according to the treatment plan with the patient remaining on the patient platform of the same setup as with imaging in a); and   iv) during radiation treatment, imaging the patient using the x-ray tube and the x-ray detector array mounted on the straight support beams on opposite sides of the patient,   wherein, if a change or changes in patient anatomy is/are detected, one or more of the treatment delivery parameters is/are adjusted,   whereupon a target in the patient is irradiated in accordance with the treatment plan.   
     
     
         17 . The method of  claim 16 , wherein the treatment delivery parameters include the position of the patient support platform, the shape of the multi-leaf collimator, the longitudinal angle of the beam, the latitudinal angle of the beam, and the beam intensity. 
     
     
         18 . The system of  claim 11 , wherein the globe gantry comprises at least two arc-shaped, gantry support arms, which are separated by longitudinal angles of 180° or at least two pairs of adjacent arc-shaped, gantry support arms, which pairs are separated by longitudinal angles of 180°.