Treatment couch with localization array

1. A method, comprising:

providing a localization array in a known position relative to a treatment couch, wherein the localization array is coupled to a positioning device of the treatment couch via an arm,

wherein the positioning device is coupled to a platform attached to the treatment couch, and

wherein the localization array and the positioning device are disposed below the treatment couch;

maintaining the localization array at substantially the known position by controlling movement of the localization array by moving the arm coupled to the localization array; and

moving the treatment couch independently of maintaining the position of the localization array wherein a detection field of the localization array continues to encompass at least one fiducial marker when moving the treatment couch.

2. The method of claim 1 , wherein controlling the movement of the localization array comprises moving the treatment couch.

3. The method of claim 1 , further comprising using the localization array to locate at least one fiducial marker.

4. The method of claim 1 , wherein maintaining the localization array at substantially the known position comprises tolerating or compensating for deviations of the localization array from the known position.

5. The method of claim 1 , further comprising:

determining the known position for the localization array; and

moving the localization array to substantially the known position.

6. The method of claim 5 , wherein determining the known position comprises determining a position where a detection field of the localization array encompasses at least one fiducial marker.

7. The method of claim 5 , wherein the known position is based on a characteristic of a signal received by the localization array from at least one fiducial marker.

8. The method of claim 5 , wherein the known position for the localization array is chosen to avoid obstructing an imaging equipment or a moving equipment.

9. The method of claim 1 , wherein maintaining the localization array at substantially the known position is performed for at least a portion of a treatment session.