Patent Number: 
Section: claims

1. A radiation therapy apparatus, comprisingan inner layer comprising:a radiation delivery device configured to emit primary radiation;a primary radiation shielding device configured to receive the primary radiation;one or more rails mounted on an inner surface of the inner layer, wherein the radiation delivery device and the primary radiation shielding device are disposed on the one or more rails; anda treatment table disposed inside the one or more rails, wherein the treatment table is configured to rotate around the vertical axis and the one or more rails are configured to rotate 360 degrees around the treatment table to deliver 4π steradians of radiation coverage to a patient positioned on the treatment table; andan outer layer comprising a secondary radiation shielding device integrated into the radiation therapy apparatus and configured to block secondary radiation, the secondary radiation shielding device comprising:a cylinder-shaped portion;a ring-shaped portion, the ring-shaped portion disposed to cover the radiation delivery device, and the primary radiation shielding device; anda housing configured to cover the secondary shielding device. 2. The apparatus of claim 1, wherein the one or more rails are disposed in a circular shape and configured to rotate around a horizontal axis. 3. The apparatus of claim 2, wherein the primary radiation shielding device is disposed opposite the radiation delivery device. 4. The apparatus of claim 1, wherein the apparatus is configured so that the radiation delivery device and the primary radiation shielding device rotate around a horizontal axis in synchrony with each other. 5. The apparatus of claim 1, wherein the housing is dome-shaped. 6. The apparatus of claim 1, wherein the housing is cylinder-shaped. 7. The apparatus of claim 1, wherein the primary radiation shielding device is configured to block at least 99.9% of radiation incident upon the primary radiation shielding device. 8. The apparatus of claim 1, wherein the secondary radiation shielding device is configured to block at least 99.9% of radiation incident upon the secondary radiation shielding device. 9. The apparatus of claim 1, wherein the cylinder shaped portion includes a closable opening through which a patient may pass in preparation for radiation therapy. 10. The apparatus of claim 9, wherein the cylinder shaped portion includes one or more doors coupled to a central portion of the cylinder shaped portion, the one or more doors covering and opening the closeable opening. 11. The apparatus of claim 1, further comprising one or more imaging sources and one or more imaging panels. 12. The apparatus of claim 11, wherein the one or more imaging sources and the one or more imaging panels are coupled to the one or more rails. 13. The apparatus of claim 11, wherein the one or more imaging sources and the one or more imaging panels are disposed inside the ring shaped portion. 14. The apparatus of claim 1, wherein the cylinder-shaped portion extends along the longitudinal center of the housing within the one or more rails. 15. The apparatus of claim 14, wherein the treatment table is movable and configured to slide inside the cylinder shaped portion. 16. The apparatus of claim 15, further comprising a gap in the cylinder shaped portion having the width of the one or more rails,the gap configured to avoid obstructing movement of the radiation delivery device and the primary radiation shielding device as the radiation delivery device and the primary radiation shielding device rotate around the horizontal axis. 17. The apparatus of claim 16, wherein the cylinder-shaped portion is configured to receive a portion of the treatment table within the gap to enable radiation emitted from the radiation delivery device to reach the patient positioned on the portion of the treatment table within the gap. 18. The apparatus of claim 16, wherein the ring shaped portion is coupled to the cylinder shaped portion at both sides of the gap. 19. The apparatus of claim 16, wherein the treatment table is configured to move between a first position over the gap and a second position away from the gap. 20. The apparatus of claim 1, wherein the steradians are solid angle units describing a direction of primary radiation applied to the patient disposed on the treatment table.