Patent Number: 
Section: claims

1. A computer-implemented method, comprising:logically dividing a target volume into two or more treatment slices to be radiated individually by radiation delivered by co-planar beams;planning a two dimensional path for moving a shaped isocenter through a treatment slice, the two dimensional path to include a set of scan points to be visited by the isocenter, the isocenter to be produced by the intersection of the co-planar beams, and where planning a first two dimensional path through a first treatment slice can begin before a second treatment slice has been defined;planning a three dimensional path for moving the shaped isocenter through the target volume based) at least in part, on two or more of the two dimensional paths; andproviding a signal to control a radiosurgery device to deliver radiation using the coplanar beams to the target volume based, at least in part, on the three dimensional path. 2. The method of claim 1, including receiving one or more pre-operative images in which at least a portion of the target volume appears, the pre-operative images being one or more of, magnetic resonance images, computed tomography images, and x-ray images. 3. The method of claim 2, including fixing one or more fiducial markers at a position relative to the target volume, where the pre-operative images are to include representations of the one or more fiducial markers; andwhere assembling, the three dimensional plan depends, at least in part, on a relationship between an image of a fiducial in a first treatment slice and an image of a fiducial in a second treatment slice. 4. The method of claim 2, including fixing one or more fiducial markers at a position relative to the target volume, where the pre-operative images are to include representations of the one or more fiducial markers; andwhere the delivery device is controlled, at least in part, on determining a relationship between a portion of the target volume and one or more of, a collimator opening, and a radiation source. 5. The method of claim 1, where logically dividing the target volume into two or more treatment slices includes determining a treatment slice thickness. 6. The method of claim 1, a two dimensional path being a raster scan path. 7. The method of claim 1, the shaped isocenter having a disk shape. 8. The method of claim 1, where a shot weight produced by the radiation delivered by the coplanar beams is modulated by controlling the movement of the isocenter. 9. The method of claim 8, where the shot weight is modulated by controlling one or more of, a number of coplanar beams applied to the target volume, a hole size in a collimator through which at least one of the coplanar beams is to pass, and a temporal delay between one or more of the coplanar beams being applied to the target volume. 10. The method of claim 1, where planning a two dimensional path through a treatment slice includes calculating a resulting dose according to:            D      d        =                            d          *          τ                ⇒                              D            d                    ⁡                      (                          x              ,              y                        )                              =                        ∑          m                ⁢                              ∑            n                    ⁢                                    d              ⁡                              (                                                      m                    -                    x                                    ,                                      n                    -                    y                                                  )                                      ⁢                          τ              ⁡                              (                                  m                  ,                  n                                )                                                          ,where D represents the resulting dose;where d represents the disk-shaped shot dose kernel;where τ represents a time series variable that represents the time it takes a moving shot to pass through a unit length of a raster line;where m represents a first index associated with a raster line scan point position; andwhere n represents a second index associated with a raster line scan point position. 11. The method of claim 10, where planning a two dimensional path through a treatment slice includes solving for τ according to:            O      ⁡              (                  τ          _                )              =                            ∑          tissue                ⁢                              ∑            i                    ⁢                                                    I                i                            ⁡                              (                                                      D                    i                    P                                    -                                      D                    i                    d                                                  )                                      2                              =                        ∑          tissue                ⁢                              ∑            i                    ⁢                                                    I                i                            (                                                D                  i                  P                                -                                                      ∑                    j                                    ⁢                                                            d                      ji                                        ⁢                                          τ                      j                                                                                  )                        2                                ,where DiP is the prescribed dose for the tumor;DiP is the planned dose distribution to be optimized; anddji of the dose kernel represents the dose contribution to the ith spatial location while the shot moves through the jth scan point. 12. The method of claim 11, where assembling the three dimensional plan includes solving for a final three-dimensional plan dose according to:      D    f    =            ∑      n        ⁢                  w        i            ·              D        i        s            where DiS is the 3D dose matrix; andwi is the weight assigned to the ith single-plane raster scan. 13. The method of claim 1, where two dimensional paths through two or more treatment slices are to be planned substantially in parallel. 14. The method of claim 1, where two dimensional paths through two different treatment slices differ in at least one of, scan pattern, importance weighted quadratic objective function, and slice orientation. 15. The method of claim 1, including controlling a delivery apparatus to deliver a set of coplanar beams according to the three dimensional plan. 16. The method of claim 15, including controlling the delivery apparatus to deliver the coplanar beams to two or more treatment slices substantially in parallel. 17. The method of claim 15, including:calibrating the delivery apparatus before controlling the delivery apparatus to deliver the coplanar beams; andcontrolling the delivery apparatus based, at least in part, on the calibration. 18. The method of claim 17, where calibrating the delivery apparatus includes acquiring a signal from a polymer gel-MRI dosimeter to which the delivery apparatus applied a set of coplanar beams. 19. The method of claim 1, including changing a tumor prescription dose between planning a set of two dimensional paths and planning the three dimensional path. 20. The method of claim 1, including dynamically altering the size of a collimator hole through which at least one beam will pass during radiation delivery to perform one or more of, modulating shot weight, and controlling isocenter location. 21. The method of claim 1, including selecting a delivery apparatus to deliver the coplanar beams based, at least in part, on the three dimensional plan. 22. The method of claim 1 where planning the two dimensional path includes considering a three dimensional dose bar interaction within a treatment slice and where assembling the three dimensional path includes considering a three dimensional dose bar interaction between treatment slices. 23. A machine-readable medium having stored thereon machine executable instructions that if executed by a machine cause the machine to perform a method, the method comprising:receiving one or more pre-operative images in which at least a portion of a target volume to be radiated appears, the pre-operative images being one or more of, magnetic resonance images, computed tomography images, and x-ray images;determining a treatment slice thickness;logically dividing the target volume into two or more treatment slices to be radiated individually by radiation delivered by co-planar beams, the treatment slices having the treatment slice thickness;planning a two dimensional path for moving a disk-shaped isocenter through a treatment slice, the two dimensional path to include a set of scan points to be visited by the isocenter, the isocenter to be produced by the intersection of the co-planar beams, the two dimensional path being a raster scan path, where two dimensional paths through two or more treatment slices are to be planned substantially in parallel;planning a three dimensional path for moving the shaped isocenter through the target volume based, at least in part, on two or more of the two dimensional paths, where a shot weight produced by the coplanar beams is modulated by controlling the movement of the isocenter;providing a signal to control a radiosurgery device to deliver radiation using the coplanar beams to the target volume based, at least in part, on the three dimensional path; andcontrolling a delivery apparatus to deliver a set of coplanar beams according to the three dimensional plan,where planning the two dimensional path includes considering a three dimensional dose bar interaction within a treatment slice and where assembling the three dimensional path includes considering a three dimensional dose bar interaction between treatment slices. 24. A radio surgical treatment method, comprising:identifying a set of two dimensional paths through a set of treatment slices, where planning a first two dimensional path through a first treatment slice can begin before a second treatment slice has been defined;receiving a treatment plan comprising a three dimensional path through a target volume based, at least in part, on the set of two dimensional paths;controlling a radio surgical apparatus to generate a disk-shaped shot having an isocenter and to continuously adjust the isocenter location to produce a coplanar shot movement through the three dimensional path; andcontrolling the radio surgical apparatus to modulate the speed at which the isocenter location moves. 25. The method of claim 24, where modulating the speed at which the isocenter location is moved includes controlling one or more robotic apparatus associated with the radio surgical apparatus to reposition one or more of, a patient, the radio surgical apparatus, and a radiation source. 26. An apparatus, comprising:a first logic to partition a target volume into a set of treatment slices, the target volume representing a tissue to be subjected to radiation delivered by a set of coplanar beams;a second logic to determine a set of two dimensional raster scanning paths through the set of treatment slices, where determining a first two dimensional raster scanning path through a first treatment slice can begin before a second treatment slice has been defined;a third logic to determine a three dimensional path to irradiate the target volume to within a pre-determined dose, the three dimensional path being based, at least in part, on the set of two dimensional raster scanning paths; anda fourth logic to control a delivery apparatus to deliver a set of coplanar beams to the target volume in accordance with the three dimensional path. 27. The apparatus of claim 26, the delivery apparatus being a modified Leksell Gamma Knife. 28. The apparatus of claim 26, the delivery apparatus comprising:a Linac unit with a collimator to shape radiation to a slit beam;a ring-shaped secondary helmet with multiple collimator channels through which multiple beams can focus to an isocenter to form a disk-shaped shot; anda robotic positioning system that connects a head frame to the ring-shaped secondary helmet. 29. The apparatus of claim 26, the delivery apparatus including a rotating secondary apparatus. 30. The apparatus of claim 26, the delivery apparatus to rotate a slit beam around a fixed portion of the delivery apparatus. 31. The apparatus of claim 26, including the delivery apparatus. 32. The apparatus of claim 31, including a dosimeter to calibrate the delivery apparatus. 33. The apparatus of claim 32, the first logic to receive a set of pre-operative images in which the target volume is represented. 34. A system, comprising:means for identifying a set of treatment slices in a target volume;means for planning a two dimensional path through a treatment slice for a focused isocenter produced by the intersection of coplanar radiation beams, where planning a first two dimensional path through a first treatment slice can begin before a second treatment slice has been defined;means for assembling a three dimensional plan for performing radiosurgery on the target volume, where the three dimensional plan depends, at least in part, on a set of two dimensional paths through treatment slices; andmeans for controlling a radiosurgery delivery apparatus to move the intersection of the coplanar radiation beams through the target volume according to the three dimensional plan.