Method for determining a range of radiation

1. A method for determining a range of particle radiation, the method comprising:

defining a target volume to be irradiated, the target volume characterized by a plurality of voxels;

determining, without exposing the target volume to particle radiation, radiation-attenuating properties that are associated with individual voxels of the plurality of voxels by performing a medical imaging procedure;

deriving a first range datum of a first voxel and range datums of two adjacent voxels from the radiation-attenuating properties; and

changing the first range datum of the first voxel when the range datum of the first voxel differs from the range datums of the two adjacent voxels.

2. The method as defined by claim 1 , wherein the determining the radiation-attenuating properties of the target volume includes using a radiology procedure.

3. The method as defined by claim 1 , wherein determining the radiation-attenuating properties includes using a computed tomography procedure.

4. The method as defined by claim 1 , wherein the radiation-attenuating properties are determined in Hounsfield units.

5. The method as defined by claim 1 , wherein the range datum of the first voxel is a water-equivalent range.

6. The method as defined by claim 5 , comprising: correcting the range datum of the first voxel whenever a lesser water-equivalent range has been determined for a first adjacent voxel and a higher water-equivalent range, in comparison to the first voxel, has been determined for a second adjacent voxel.

7. The method as defined by claim 6 , wherein the first and second adjacent voxels that are adjacent to the first voxel and have a lesser or higher water-equivalent range are disposed on opposite sides of the first voxel.

8. The method as defined by claim 7 , wherein correcting the range datum includes reducing the water-equivalent range associated with the first voxel.

9. The method as defined by claim 1 , wherein the first voxel has a density that is different than densities of the two adjacent voxels.

10. The method as defined by claim 1 , wherein changing the first range datum includes changing the first range datum of the first voxel when the range datum of the first voxel differs from the range datums of the two adjacent voxels in different ways.

11. The method as defined by claim 1 , wherein changing includes determining whether the first range datum of the first voxel differs from the range datums of the two adjacent voxels.

12. An apparatus for determining a range of radiation, the apparatus comprising:

a diagnostic device that is operable to obtain radiation-attenuating properties of a target volume; and

a computation unit that is operable to derive a range datum from the radiation-attenuating properties of the target volume and change the range datum of a first voxel if the range datum of the first voxel differs from range datums of two adjacent voxels,

wherein the first voxel and two adjacent voxels are voxels of the target volume.

13. The apparatus as defined by claim 12 , wherein the radiation-attenuating properties of the target volume are derived using a radiology procedure.

14. The apparatus as defined by claim 9 , wherein the radiation-attenuating properties of the target volume are derived using a computed tomography procedure.

15. The apparatus as defined by claim 12 , wherein the range of radiation is a range of particle radiation.

16. The apparatus as defined by claim 12 , wherein the range datum of the first voxel is a water-equivalent range, and wherein the computation unit is operable to correct the range datum of the first voxel whenever a lesser water-equivalent range has been determined for a first adjacent voxel and a higher water-equivalent range, in comparison to the first voxel, has been determined for a second adjacent voxel.

17. The apparatus as defined by claim 12 , further comprising a therapy device that is controllable by the computational unit in accordance with changed range datum.