Algum conteúdo deste aplicativo está indisponível no momento.
Se esta situação persistir, por favor entre em contato conoscoFale conosco & Contato
1. (WO2019032911) SYSTEMS AND METHODS FOR FAULT DETECTION IN EMISSION-GUIDED RADIOTHERAPY
Nota: O texto foi obtido por processos automáticos de reconhecimento ótico de caracteres.
Para fins jurídicos, favor utilizar a versão PDF.

CLAIMS

1. An radiotherapy system comprising:

a rotatable gantry;

a first array of positron emission detectors mounted on the gantry and a second array of positron emission detectors mounted on the gantry opposite the first array of positron emission detectors;

a therapeutic radiation source mounted on the rotatable gantry between the first and second arrays of positron emission detectors;

a housing disposed over the rotatable gantry and comprising a bore and a stationary radiation source holder spaced away from a patient region within the bore, wherein the stationary radiation source holder is located within the housing or on a surface of the housing; and

a processor configured to receive positron emission data detected from the first and second arrays of positron emission detectors and to extract positron emission data representing positron emission activity originating from the stationary radiation source holder, and to generate a fault signal when the extracted positron emission data does not satisfy one or more threshold criteria.

2. The system of claim 1, further comprising a patient support, the patient support comprising a movable support surface and a base.

3. The system of claim 2, wherein the radiation source holder is disposed along the surface of the housing at a location above the patient scan region.

4. The system of claim 2, wherein the radiation source holder is located below the movable support surface.

5. The system of claim 1, further comprising a calibration radiation source held by the radiation source holder, the calibration source comprising a radioactivity of about 1 μθ to 300 μθ.

6. The system of claim 1, further comprising a calibration radiation source configured to be retained by the radiation source holder, the calibration source comprising a shape with a maximum dimension from about 0.25 inch to about 3 inches.

7. The system of claim 6, wherein the calibration radiation source comprises a disk-shaped enclosure and a positron-emitting element located within the enclosure.

8. The system of claim 1, wherein the processor is further configured to concurrently extract the positron emission data representing positron emission activity originating from the radiation source holder and to extract positron emission data representing positron emission activity originating from the patient scan region.

9. The system of claim 1, wherein a threshold criterion comprises a spatial filter that selects for positron emission activity originating from a location of the stationary radiation source holder, and wherein a fault signal is generated when applying the spatial filter to the extracted positron emission data indicates that the positron emission activity does not co-localize with the location of the stationary radiation source holder.

10. The system of claim 9, wherein the spatial filter is user adjustable.

11. The system of claim 9, wherein the processor is further configured to automatically adjust a geometry of the spatial filter using a patient treatment plan.

12. The system of claim 1, wherein the first and second arrays of positron emission detectors define an imaging plane, wherein a beam of the therapeutic radiation source defines a treatment plane, and the imaging plane and the treatment plane are co-planar.

13. The system of claim 12, wherein the stationary radiation source holder is co-planar with the imaging plane and the treatment plane.

14. The system of any one of claims 5-7, wherein the stationary

radiation source holder comprises a groove having a shape that corresponds with a shape of the radiation source.

15. The system of claim 1, wherein a threshold criterion comprises a threshold number of coincident photon events detected with a first time difference,

wherein the processor is configured to generate a plot of an actual number of coincident photon events detected with the time difference, and

wherein a fault signal is generated when the actual number of coincident photon events occurring with the time difference does not exceed the threshold number.

16. The system of claim 15, wherein a threshold criterion comprises a threshold true-to-random ratio value,

wherein the processor is configured to generate a ratio of the actual number of coincident photon events occurring within a first coincidence time window centered around 0 ns to an actual number of coincident photon events occurring within a second coincidence time window that does not overlap with the first coincidence time window, and

wherein a fault signal is generated if the ratio does not exceed the threshold true-to-random ratio value.

17. The system of claim 16, wherein the threshold true-to-random ratio value is about 1.

18. The system of claim 1, wherein a threshold criterion comprises a first expected number of coincident photon events to be detected with a first detection time difference of about 2.5 ns at a first gantry location of the first array of positron emission detectors and a second expected number of coincident photon events to be detected with a detection time difference of about 2.5 ns at a second gantry location of the first array of the positron emission detectors that is 180° from the first gantry location,

wherein the processor is configured to generate a plot of actual numbers of coincident photon events detected within a coincidence time window between -5 ns to +5 ns over a 360° gantry rotation based on positron emission data detected by the first and second arrays of positron emission detectors, and

wherein a fault signal is generated when an actual number of coincident photon events detected with a detection time difference of about 2.5 ns at the first gantry location of the first array of the positron emission detectors does not meet or exceed the first expected number, and an actual number of coincident photon events detected with a detection time difference of about 2.5 ns at the second gantry location of the first array of the positron emission detectors does not meet or exceed the second expected number.

19. The system of claim 1, wherein a threshold criterion comprises an expected number of coincident photon events to be detected by each positron emission detector of the first and second arrays at each gantry location over a 360° gantry rotation,

wherein the processor is configured to calculate, using the positron emission data detected by the first and second array of

positron emission detectors, an actual number of coincident photon events detected by each positron emission detector of the first and second arrays at each gantry location over a 360° gantry rotation, and

wherein a fault signal is generated when a difference between the actual number of coincident photon events and the expected number of coincident photon events exceeds a predetermined difference threshold for at least one positron emission detector.

20. The system of claim 1, wherein a fault signal is generated when the processor does not detect any positron emission data representing positron emission activity originating from the stationary radiation source holder.

21. The system of claim 1, wherein a threshold criterion comprises an energy resolution spectrum with a coincident 511 keV photon event count above a peak threshold, and wherein a fault signal is generated when an energy resolution spectrum generated from the positron emission data does not have a 511 keV photon event count above the peak threshold.

22. The system of claim 1, further comprising a display and wherein the processor is configured to generate a visual indicator and transmitting the visual indicator to the display, wherein the visual indicator has a first appearance in the absence of a fault signal and a second appearance different from the first appearance when a fault signal is generated.

23. An imaging assembly comprising:

a gantry comprising a first array of rotatable positron emission detectors and a second array of rotatable positron emission detectors opposing the first array of detectors;

a housing disposed over the gantry and comprising a bore and a stationary radiation source spaced away from a patient scan region within the bore, wherein the stationary radiation source is located within the housing or on a surface of the housing; and

a processor configured to receive positron emission path data from the first and second arrays of rotatable positron emission detectors and to classify positron emission path data that originates from the stationary radiation source, and to generate a fault signal when the stationary radiation source positron emission path data exceeds a threshold parameter.

24. The assembly of claim 23, wherein a pair of photons emitted by a positron annihilation event generates a positron emission path, and wherein the processor is configured to classify the positron emission path data that originates from the stationary radiation source using a difference between a reception time of the pairs of photons within a time threshold parameter range.

25. The assembly of claim 24, wherein the threshold parameter is a location deviation threshold, and wherein the processor is configured to locate the stationary radiation source based on the reception time difference of the pairs of photons, and to generate the fault signal when the location of the stationary radiation source exceeds the location deviation threshold.

26. The assembly of claim 25, wherein a pair of photons emitted by a positron annihilation event generates a positron emission path, wherein the threshold parameter is a time difference range, and wherein the processor is configured to generate the fault signal when a difference between a reception time of the pairs of photons is outside of the time difference range.

An imaging assembly compri

a gantry comprising a first array of positron emission detectors and a second array of positron emission detectors opposing the first array of detectors;

a housing coupled to the gantry, the housing comprising a bore and an annular radiation source about the bore; and

a processor configured to receive positron emission data from the first and second arrays of positron emission detectors and to distinguish the positron emission data from the annular radiation source, and to generate a fault signal when the positron emission data from the annular radiation source exceeds a threshold parameter.

28. The assembly of claim 27, wherein the processor is further

configured to concurrently classify the positron emission data from the annular radiation source and from a patient scan region within the bore.

29. The assembly of claim 28, wherein the processor is further

configured with a spatial filter to distinguish the positron emission data from the annular radiation source and from the patient scan region.

30. The assembly of claim 27, wherein the first array and second array of detectors are stationary.

31. The assembly of claim 27, wherein the first array and second array of detectors are rotatable.

32. An imaging assembly comprising:

a gantry comprising a first array of rotatable positron emission detectors and a second array of rotatable positron emission detectors opposing the first array of detectors;

one or more radiation source holders coupled to the gantry such that the one or more radiation source holders are fixed relative to the first array and the second array of detectors; and

a processor configured to receive positron emission data from the first and second arrays of rotatable positron emission detectors and to distinguish the positron emission data from the one or more radiation source holders, and to generate a fault signal when the positron emission data from the one or more radiation source holders exceeds a threshold parameter.

33. The assembly of claim 32, wherein the gantry comprises a bore, wherein the bore comprises a patient scan region spaced away from the one or more radiation source holders, and the processor is further configured to distinguish the positron emission data from the patient scan region in the bore.

34. The assembly of claim 31, wherein the one or more radiation

source holders comprise at least four radiation source holders.

35. The assembly of claim 31, further comprising one or more

radiation sources held by the corresponding one or more radiation source holders, the one or more radiation sources comprising a radioactivity of about Ι μΟ to 300 μθ and an energy of about 511 keV.

36. The assembly of claim 32, further comprising one or more

radiation sources held by the corresponding one or more radiation source holders, the one or more radiation sources comprising a shape selected from the group consisting of a cylinder, sphere, and ring.

37. An imaging method comprising:

receiving concurrent positron emission data from a patient and a calibration source spaced away from the patient, using a first array of positron emission detectors and a second array of positron emission detectors opposing the first array of detectors;

distinguishing the positron emission data from the patient and from the calibration source;

generating calibration data using the positron emission data from the calibration source;

generating patient data using the positron emission data from the patient; and

generating a fault signal when the calibration data exceeds a threshold parameter.

38. The method of claim 37, wherein distinguishing the positron

emission data from the patient and from the calibration source comprises spatially filtering the positron emission data.

39. The method of claim 37, further comprising adjusting the spatial filtering before applying the spatial filtering.

40. The method of claim 39, wherein adjusting the spatial filtering is performed using a patient treatment plan.

41. The method of claim 38, wherein the spatial filtering of the

positron emission data comprises excluding the positron emission data located outside a calibration region and a patient region.

42. The method of claim 37, wherein receiving the concurrent positron emission data occurs concurrently with generating the fault signal.

43. The method of claim 37, further comprising treating the patient using a radiation source concurrently while receiving the

concurrent positron emission data from the patient and from the calibration source.

44. The method of claim 43, further comprising stopping treatment of the patient using the radiation source in response to generating the fault signal.

45. The method of claim 37, further comprising deactivating one or more of the positron emission detectors based on the generation of the fault signal.

46. The method of claim 37, further comprising deactivating up to three of the first array and second array of detectors based on the generation of the fault signal, wherein the fault signal comprises a fault in up to three of the detectors.

47. The method of claim 37, further comprising deactivating all of the detectors based on the generation of the fault signal, wherein the fault signal comprises a fault in four or more of the detectors.

48. The method of claim 37, further comprising calibrating one or more positron emission detectors using the calibration data.

49. The method of claim 37, wherein the positron emission data

corresponds to lines of response non-intersecting with a patient imaging field of view of the detectors, the patient imaging field of view comprising a patient scan region.

50. The method of claim 37, further comprising verifying a positron emission detector calibration monitoring system coupled to the detectors based on the generation of the fault signal.