Rotatable gantry radiation treatment system

1. A radiation treatment apparatus, comprising:

a gantry frame;

a rotatable gantry structure rotatably coupled to the gantry frame, the rotatable gantry structure being rotatable around a rotation axis passing through an isocenter, the rotatable gantry structure comprising a first beam member extending between first and second ends of the rotatable gantry structure; and

a radiation treatment head movably mounted to the first beam member in a manner that allows (i) translation of the radiation treatment head along the first beam member between the first and second ends, and (ii) gimballing of the radiation treatment head relative to the first beam member, the gimballing comprising pivotable movement in at least two independent pivot directions defined with respect to the first beam member, wherein the rotatable gantry structure is rotably coupled and radiation treatment head is movably mounted to provide non-coplanar radiation treatment of a tissue volume positioned near or around the isocenter, wherein the first beam member is movable away from the rotation axis to increase a distance between the radiation treatment head and the rotation axis, and wherein the first beam member is movable toward the rotation axis to decrease the distance between the radiation treatment head and the rotation axis.

2. The radiation treatment apparatus of claim 1 , the rotatable gantry structure further comprising first and second ring members corresponding to the first and second ends, respectively, and wherein the first and second ring members are rotatable around the rotation axis, the first beam member being fixably coupled to the first and second ring members.

3. The radiation treatment apparatus of claim 1 , wherein a transverse isocentric plane being defined that passes through the isocenter in a direction orthogonal to the rotation axis, wherein the at least two independent pivot directions include a first pivot direction around a first pivot axis generally parallel to the transverse isocentric plane and a second pivot direction around a second pivot axis nonparallel to the first pivot axis.

4. The radiation treatment apparatus of claim 1 , further comprising an imaging system comprising an imaging source and an imaging detector, wherein the imaging source and imaging detector are fixably mounted on the gantry frame at opposing positions relative to the isocenter.

5. The radiation treatment apparatus of claim 4 , wherein the imaging system comprises a first imaging source, a second imaging source, and first and second imaging detectors respectively opposite the first and second imaging sources, wherein the first imaging source and the second imaging source are mounted to obtain stereo images of the isocenter at a non-zero angle relative to each other.

6. The radiation treatment apparatus of claim 1 , the rotatable gantry structure comprising second and third beam members distal from the rotation axis and extending between the first and second ends, wherein the second and third beam members are disposed generally opposite each other relative to the rotation axis, and wherein the radiation treatment apparatus further comprises an imaging system including an imaging source mounted on the second beam member and an imaging detector mounted on the third beam member.

7. The radiation treatment apparatus of claim 1 , further comprising a patient couch operative coupled in the radiation treatment apparatus in manner to provide movement of the couch relative to the radiation treatment head.

8. The radiation treatment apparatus of claim 7 , further comprising a controller operatively coupled with the patient couch and the radiation treatment head to control movement of the patient couch and gimbaling of the radiation treatment head.

9. A radiation treatment apparatus, comprising:

a gantry frame;

a rotatable gantry structure rotatably coupled to the gantry frame, the rotatable gantry structure being rotatable around a rotation axis passing through an isocenter, the rotatable gantry structure comprising a first beam member extending between first and second ends of the rotatable gantry structure;

a radiation treatment head movably mounted to the first beam member in a manner that allows (i) translation of the radiation treatment head along the first beam member between the first and second ends, and (ii) gimballing of the radiation treatment head relative to the first beam member, the gimballing comprising pivotable movement in at least two independent pivot directions defined with respect to the first beam member, wherein the rotatable gantry structure is rotably coupled and radiation treatment head is movably mounted to provide non-coplanar radiation treatment of a tissue volume positioned near or around the isocenter, wherein the rotatable gantry structure being a first rotatable gantry structure;

a second rotatable gantry structure rotatably coupled to the gantry frame, the second rotatable gantry structure being rotatable around tje rotation axis concentrically with, and independently of, the first rotatable gantry structure;

the second rotatable gantry structure comprising second and third beam members each distal from the rotation axis and extending between opposing ends thereof, the second and third beam members being disposed generally opposite each other relative to the rotation axis; and

an imaging system comprising an imaging source positioned on the second beam member and an imaging detector positioned on the third beam member.

10. The radiation treatment apparatus of claim 9 , the imaging source being a first imaging source and the imaging detector being a first imaging detector, wherein the imaging system comprises:

a second imaging source; and

a second imaging detector opposite the second imaging source, wherein the first imaging source and the second imaging source are mounted to obtain stereo images of the isocenter at a non-zero angle relative to each other.

11. The radiation treatment apparatus of claim 9 , a transverse isocentric plane being defined that passes through the isocenter in a direction orthogonal to the rotation axis, wherein the imaging source is translatable along the second beam member between the first and second ends, and wherein the imaging detector is translatable along the third beam member between the first and second ends, wherein the imaging system is configured to image the tissue volume at a plurality of different imaging angles relative to the transverse isocentric plane.