Patent Number: 
Section: claims

1. A method of performing high energy microbeam radiosurgery on a patient, comprising:irradiating a target tissue, within a patient, with high energy electromagnetic radiation via one or more microbeam envelopes which are mutually spatially distinct and each of which has a respective maximum defined beam width, whereinsaid high energy electromagnetic radiation includes photons having respective energy magnitudes within a spectrum with a peak value in excess of 200 keV,said peak value and said maximum defined beam width yield a graded lateral dose profile having a peak dose and non-abrupt transitions to first and second valley doses, andeach of said one or more microbeam envelopes yields a biological damage width defined by a width of said graded lateral dose profile above a threshold dose value which is between said peak and valley doses and above which biological damage occurs. 2. The method of claim 1, wherein tissue adjacent each of said one or more microbeam envelopes supports recovery of non-target tissue. 3. The method of claim 1, wherein said one or more microbeam envelopes comprises a plurality of microbeam envelopes which are mutually spatially distinct. 4. The method of claim 3, wherein adjacent ones of said plurality of microbeam envelopes are mutually separated by a minimum defined inter-beam spacing to provide an undamaged tissue width which is sufficient to promote healing of damaged non-target tissue. 5. The method of claim 3, wherein other tissue between adjacent ones of said plurality of microbeam envelopes supports recovery of non-target tissue. 6. The method of claim 3, wherein said plurality of microbeam envelopes have substantially equal beam widths. 7. The method of claim 3, wherein adjacent ones of said plurality of microbeam envelopes are mutually separated by a minimum defined inter-beam spacing substantially greater than said maximum defined beam width. 8. The method of claim 3, wherein:adjacent ones of said microbeam envelopes are mutually separated by a minimum defined inter-beam spacing; anda ratio of said minimum defined inter-beam spacing to said maximum defined beam width is greater than or equal to two. 9. The method of claim 3, wherein said plurality of microbeam envelopes comprises a plurality of substantially mutually parallel microbeam envelopes. 10. The method of claim 1, wherein a ratio of said peak dose value to said threshold dose value is greater than or equal to 10. 11. The method of claim 1, wherein said width of said graded lateral dose profile at said threshold dose value is less than or equal to 700 microns.