High resolution dynamic detector for imaging and dosimetry in megavoltage radiation therapy
Disclosed herein are variations of megavoltage (MV) detectors that may be used for acquiring high resolution dynamic images and dose measurements in patients. One variation of a MV detector comprises a scintillating optical fiber plate, a photodiode array configured to receive light data from the optical fibers, and readout electronics. In some variations, the scintillating optical fiber plate comprises one or more fibers that are focused to the radiation source. The diameters of the fibers may be smaller than the pixels of the photodiode array. In some variations, the fiber diameter is on the order of about 2 to about 100 times smaller than the width of a photodiode array pixel, e.g., about 20 times smaller. Also disclosed herein are methods of manufacturing a focused scintillating fiber optic plate.
1. A method of manufacturing an optical fiber plate comprising:
providing a block of parallel scintillating optical fibers;
slicing the block along a first axis that transects the optical fibers at a first angle with respect to the parallel fibers to create a top surface;
slicing the block along a second axis that transects the optical fibers at a first distance away from the top surface to create a bottom surface, wherein the bottom surface is parallel to the top surface;
slicing the block along a third axis to create a first side surface that is at a second angle with respect to the top surface; and
slicing the block along a fourth axis at a second distance away from the third axis to create a second side surface, wherein the second side surface is at a third angle with respect to the top surface.
2. The method of claim 1 , wherein the first distance is a thickness of an optical fiber plate and the second distance is a width of the optical fiber plate.
3. The method of claim 2 , wherein the third angle is different from the second angle.
4. The method of claim 2 , wherein the first angle is from about 10 degrees to about 180 degrees.
5. The method of claim 4 , wherein the second and third angles are from about 0.5 degrees to about 40 degrees.
6. The method of claim 5 , wherein the scintillating fiber located at the center of the optical fiber plate is at a fourth angle such that the center scintillating fiber is aligned with a ray of a radiation source fan beam located at a fixed distance away from the optical fiber plate.
7. The method of claim 1 , further comprising slicing the block along a fifth axis to create a third side surface and a sixth axis at a third distance away from the fifth axis to create a fourth side surface, wherein the third side surface is at a fourth angle with respect to the top surface and the fourth side surface is at a fifth angle with respect to the top surface.
8. The method of claim 1 , wherein the scintillating optical fibers comprise plastic scintillating optical fibers.
9. The method of claim 1 , wherein the scintillating optical fibers have a diameter from about from about 5 μm to about 10 μm.
10. The radiation detector of claim 9 , wherein the fiber diameter is about 10 μm.
11. A method of manufacturing an optical fiber plate comprising:
providing a billet of tapered scintillating optical fibers;
slicing the billet along a first axis that transects all of the fibers to create a top surface;
slicing the billet along a second axis that transects all of the fibers at a first distance away from the first cut to create a bottom surface, wherein the bottom surface is parallel to the top surface;
slicing the billet along a third axis to create a first side surface that is at a first angle with respect to the top surface; and
slicing the billet along a fourth axis at a second distance away from the third axis to create a second side surface that is at a second angle with respect to the top surface.
12. The method of claim 11 , wherein the billet of scintillating optical fibers is thermally tapered.
13. The method of claim 11 , wherein the taper angle of the billet of optical fibers is determined at least in part by the shape of a radiation beam from a radiation source that is to be located at a fixed distance away from the optical fiber plate.
14. The method of claim 11 , wherein the first side surface extends along a length of a first boundary fiber in the tapered billet, and the second side surface extends along a length of a second boundary fiber in the tapered billet.
15. The method of claim 11 , wherein the scintillating optical fibers comprise plastic scintillating optical fibers.
16. The method of claim 11 , wherein the scintillating optical fibers have a diameter from about from about 5 μm to about 10 μm.
17. The radiation detector of claim 16 , wherein the fiber diameter is about 10 μm.