Treatment couch for small isocentric rotations

1. A treatment system for a patient, comprising:

a radiation delivery apparatus;

a gantry configured to rotate the radiation delivery apparatus about a horizontal axis, thereby defining an isocenter; and

a treatment couch to position the patient, comprising:

a couch top;

a pitch and roll stage configured to pitch and roll the couch top about pitch and roll axes;

a lateral and longitudinal translation stage to translate the couch top along lateral and longitudinal translation axes;

an angular stage to rotate the couch top about a first vertical rotation axis; and

a vertical stage to translate the couch top along a vertical translation axis; and

a controller programmed to perform a rotation of the treatment couch about a second vertical rotation axis by dynamically moving both the angular stage and the lateral and longitudinal translation stage to rotate the couch top about the first vertical rotation axis and translate the couch top along the lateral and the longitudinal translational axes, wherein the first vertical rotation axis is proximal to a first end of the couch top away from the radiation delivery apparatus, and the second vertical axis is proximal to a second end of the couch top near the radiation delivery apparatus.

2. The treatment system of claim 1 , wherein the controller is programmed to provide motion to the couch top on two or more axes simultaneously during a radiation treatment in order to compensate for tumor motions or follow a dynamic treatment plan.

3. The treatment system of claim 1 , wherein the angular stage comprises rotation mechanisms located outside of a radiation field of the radiation delivery apparatus for an entire longitudinal travel of the couch top.

4. The treatment system of claim 1 , wherein:

the vertical stage is fixed to a floor;

the angular stage is mounted on the vertical stage;

the lateral and longitudinal translation stage is mounted on the angular stage;

the pitch and roll stage is mounted on the lateral and longitudinal translation stage; and

the couch top is mounted on the pitch and roll stage.

5. The treatment system of claim 1 , wherein:

the vertical stage is fixed to a floor;

the lateral and longitudinal translation stage is mounted on the vertical stage;

the angular stage is mounted on the lateral and longitudinal translation stage;

the pitch and roll stage is mounted on the angular stage; and

the couch top is mounted on the pitch and roll stage.

6. The treatment system of claim 1 , wherein an individual axis includes one or more readout sensors.

7. The treatment system of claim 1 , wherein the second vertical rotation axis passes through the isocenter.

8. A treatment system for a patient, comprising:

a treatment couch to position the patient, comprising:

a couch top; and

one or more stages to:

pitch the couch top about a lateral axis or roll the couch top about a longitudinal axis;

translate the couch top along lateral and longitudinal directions;

rotate the couch top about a vertical axis; and

translate the couch top along vertical directions;

wherein:

the one or more stages include an angular stage to rotate the coach top about the vertical axis; and

the angular stage comprises:

a base;

a top rotatably coupled to the base; and

a drive mechanism to rotate the top relative to the base about the vertical axis, the drive mechanism comprising:

a motor mounted to the base, the motor comprising a pinion; and

a curved rack mounted to the top and engaged to the pinion.

9. A treatment system for a patient, comprising:

a treatment couch to position the patient, comprising:

a couch top; and

one or more stages to:

pitch the couch top about a lateral axis or roll the couch top about a longitudinal axis;

translate the couch top along lateral and longitudinal directions;

rotate the couch top about a vertical axis; and

translate the couch top along vertical directions;

wherein:

the one or more stages include an angular stage to rotate the coach top about the vertical axis; and

the angular stage comprises:

a base;

a top rotatably coupled to the base; and

a drive mechanism to rotate the top relative to the base about the vertical axis, the drive mechanism comprising a linear actuator having a first end pivotally fixed to the top and a second end pivotally fixed to the base.

10. A treatment method comprising:

rotating a couch top about a first vertical rotation axis proximal to a first end of the couch top proximate to a radiation delivery apparatus, comprising:

rotating with an angular stage, the couch top about a second vertical rotation axis, the second vertical rotation axis being proximal to a second end of the couch top away from the radiation delivery apparatus; and

translating with a lateral and longitudinal translation stage, the couch top along horizontal lateral and longitudinal axes to compensate for lateral and longitudinal displacements of the first vertical rotation axis cause by said rotating.

11. The method of claim 10 , wherein said rotating and said translating occur simultaneously.

12. The method of claim 11 , further comprising at least one of pitching the couch top about the horizontal lateral axis and rolling the couch top about the horizontal longitudinal axis to compensate for a deflection in the couch top, patient misalignments, or tumor rotations.

13. The method of claim 10 , further comprising providing motion to the couch top on two or more axes simultaneously during a radiation treatment in order to compensate for tumor motions or follow a dynamic treatment plan.

14. The method of claim 10 , further comprising rotating a radiation delivery apparatus about a horizontal rotation axis, thereby defining the isocenter, the first vertical rotation axis passing through the isocenter.