Image guided radiation therapy apparatus

1. A radiation therapy apparatus comprising:

radiation source configured to emit radiation;

a first connector bolt:

a second connector bolt:

a peg comprising an aperture: and

a ring-shaped gantry including:

a static ring component having a bearing mount; and

a dynamic ring component upon which the radiation source is mounted, the dynamic ring component being rotatable about its center and including multiple arcuate parts assembled together to form the dynamic ring component, at least one of the arcuate parts being secured to the bearing mount of the static ring component, the arcuate parts comprising bores which align when the dynamic ring component is assembled, wherein:

a first pair of aligned bores near a front face of the dynamic ring component is configured to receive the first connector bolt;

a second pair of aligned bores near a rear face of the dynamic ring component is configured to receive the second connector bolt;

the ends of the arcuate parts define at least one additional bore when two adjacent ends of two arcuate pieces are aligned, the at least one additional bore extending in a longitudinal direction of the dynamic ring component substantially orthogonal to the first and second pairs of aligned bores; and

the at least one additional bore is configured to receive the peg, the peg receiving at least one of the first or second connector bolts through the aperture.

2. The radiation therapy apparatus as claimed in claim 1 , wherein the radiation therapy apparatus is an image guided radiation therapy apparatus comprising a medical imaging device.

3. The radiation therapy apparatus as claimed in claim 2 , wherein the medical imaging device is a Magnetic Resonance Imaging (MRI) device.

4. The radiation therapy apparatus as claimed in claim 1 , wherein the multiple arcuate parts are of equal size.

5. The radiation therapy apparatus as claimed in claim 4 , wherein the dynamic ring component comprises three arcuate parts.

6. The radiation therapy apparatus as claimed claim 1 , wherein the multiple arcuate parts are different sizes.

7. The radiation therapy apparatus as claimed in claim 1 , wherein the first and second connector bolts are sized to fit through the first and second pair of aligned bores.

8. The radiation therapy apparatus as claimed in claim 1 , further comprising at least one shim plate configured to be located radially from the inner circumference of the assembled dynamic ring component.

9. The radiation therapy apparatus as claimed in claim 8 , wherein the at least one shim plate includes an aperture for receiving at least one of the first or second connector bolts to hold the at least one shim plate in position between adjacent end surfaces of two arcuate pieces.

10. The radiation therapy apparatus as claimed in claim 1 , wherein the multiple arcuate parts are marked to identify their proper position and/or orientation in the dynamic ring component.

11. The radiation therapy apparatus as claimed in claim 1 , wherein the radiation source comprises a linear accelerator.

12. The radiation therapy apparatus as claimed in claim 1 , wherein the radiation source comprises a radioisotope source.

13. The radiation therapy apparatus as claimed in claim 1 , wherein the assembled dynamic ring component has a consistent diameter throughout the dynamic ring component.

14. An image-guided radiation therapy apparatus, comprising:

a medical imaging device;

a radiation source configured to emit radiation; and

a ring-shaped gantry comprising;

a static ring component having a bearing mount; and

a dynamic ring component upon which the radiation source is mounted, wherein:

the dynamic ring component is rotatable about its center;

the dynamic ring component includes multiple arcuate parts assembled together to form the dynamic ring component, the arcuate parts comprising bores which align when the dynamic ring component is assembled, a first pair of aligned bores near a front face of the dynamic ring component configured to receive a first connector bolt, and a second pair of aligned bores near a rear face of the dynamic ring component configured to receive a second connector bolt;

the ends of the arcuate parts define at least one additional bore when two adjacent ends of two arcuate pieces are aligned, the at least one additional bore extending in a longitudinal direction of the dynamic ring component substantially orthogonal to the first and second pairs of aligned bores;

the at least one additional bore is configured to receive a peg comprising an aperture, the peg receiving at least one of the first or second connector bolts through the aperture;

the assembled dynamic ring component has a consistent diameter, throughout the dynamic ring component; and

at least one of the arcuate parts is secured to the bearing mount of the static ring component.

15. The image-guided radiation therapy apparatus as claimed in claim 14 , wherein the medical imaging device is a Magnetic Resonance Imaging (MRI) device integrated with the radiation therapy apparatus.