Disposable single-use external dosimeters for detecting radiation in fluoroscopy and other medical procedures/therapies

• US 20050090738A1
• Filed: 06/10/2004
• Published: 04/28/2005
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: SNC Holdings Corp.
• Original Assignee: SNC Holdings Corp.
• Inventors: Widener, Steven R., Mann, Gregory Glenwood, Lehman, Phillip M., Black, Robert D., Carroll, John
• Granted Patent: US 7,966,054 B2
• Time in Patent Office: Days
• US Class Current: 600/436
• CPC Class Codes: A61N 2005/1072 taking into account movement of the target
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 5/1071 for verifying the dose delivered by the treatment plan
• CPC Class Codes: G01T 1/026 Semiconductor dose-rate meters

Abstract

Methods, systems, devices, and computer program products include positioning single-use radiation sensor patches that have adhesive onto the skin of a patient to evaluate the radiation dose delivered during a medical procedure or treatment session. The sensor patches are configured to be relatively unobtrusive and operate during radiation without the use of externally extending power cords or lead wires.

Claims

1. A method for monitoring radiation exposure for a patient undergoing a medical procedure, comprising:

releasably securing at least one single-use dosimeter sensor patch onto the skin of the patient, wherein the patch is self-contained;

exposing the patient to radiation in a medical procedure, wherein the at least one patch comprises a radiation sensor circuit having a MOSFET that is unpowered during radiation exposure;

transmitting data from the sensor patch to a dose-reader device after the exposing step to obtain data associated with a change in an operational parameter of the MOSFET in the dosimeter sensor patch; and

determining radiation received by the patient during the exposing step based on the change in the MOSFET operational parameter.

2. A method according to claim 1, wherein an underside of the at least one patch comprises an adhesive, and wherein the releasably securing step is carried out by pressing the patch onto the skin so that it adheres thereto.

3. A method according to claim 1, wherein the transmitting data is carried out by inserting a tab extending from the at least one sensor patch into a port in the dose-reader device.

4. A method according to claim 1, further comprising at least one of calibrating and/or pre-dosing the at least one single-use dosimeter sensor patch before releasably securing the sensor patch onto the skin of the patient.

5. A method according to claim 1, wherein the at least one dosimeter patch comprises a plurality of spaced apart discrete radiation sensor circuits, each comprising a single MOSFET.

6. A method according to claim 1, further comprising storing radiation-data relating to the exposing and/or determining step on a memory device integrated with the at least one sensor patch.

7. A method according to claim 1, further comprising storing a plurality of patient specific data records in the reader, then transmitting the radiation data obtained by the reader from the at least one sensor patch to a remote computer.

8. A method according to claim 1, further comprising sterilizing the single-use dosimeter sensor patch and applying an adhesive to a selected primary surface, and packaging the single-use dosimeter patch in a sterile package suitable for human medical use.

9. A method according to claim 1, wherein the medical procedure is a fluoroscopic procedure.

10. A method according to claim 1, wherein the at least one single-use dosimeter patch has a low profile and is generally conformable to the underlying skin of the patient, and wherein the step of releasably securing comprises positioning the patch proximate a target radiation beam path configured to enter into the body about a chest portion of the patient.

11. A method according to claim 10, further comprising positioning at least one of the patches proximate to a region where radiation is not desired or in a radiation-sensitive region.

12. A method according to claim 9, wherein the at least one patch comprises a first patch that comprises a plurality of spaced apart radiation sensors, each radiation sensor comprising a single-MOSFET, and wherein the positioning is carried out so as to place at least one radiation sensor held on the first patch in a location that is generally centered on the patient within a projected radiation beam patient entry window used in the fluoroscopic procedure.

13. A method according to claim 12, wherein the at least one single-use dosimeter patch is a low profile discrete flexible single use patch having a predetermined surface area that is sufficient to cover at least a major portion of a predicted fluoroscopic skin-exposure area, wherein the radiation sensor elements are adapted to provide individual radiation dose data, and wherein the releasably securing step comprises positioning the patch over at least a portion of the predicted fluoroscopic exposure surface area of the patient.

14. A method according to claim 13, wherein the first patch is generally circular.

15. A method according to claim 13, wherein the first patch comprises a substrate that allows radiation to pass substantially unimpeded.

16. A method according to claim 15, wherein a plurality of the respective radiation sensors are generally circumferentially spaced apart.

17. A method according to claim 15, wherein each radiation sensor comprises a plurality of conductive traces, at least one extending from a respective radiation sensor circuit to an outer edge portion of the first patch, and wherein the conductive traces comprise aluminum.

18. A method according to claim 17, wherein the first dosimeter sensor patch comprises electronic memory, and wherein the method further comprises storing patient data in the electronic memory.

19. A method according to claim 17, wherein the dose reader device is configured as a portable substantially pocket/palm sized device.

20. A method according to claim 1, wherein the at least one single-use dosimeter patch is a low-profile discrete flexible single use patch having a predetermined length and width sufficient to cover at least a major portion of a predicted radiation beam path, wherein the at least one single-use dosimeter patch comprises electronic memory, wherein the step of releasably securing comprises positioning the patch over the predicted beam path on the skin of the patient, and wherein the method further comprises storing patient data in the electronic memory.

21. A method according to claim 17, wherein the sensor patch is adapted to be inserted into the dose-reader device and the dose-reader device is adapted to receive the sensor patch, and wherein the transmitting step comprises physically contacting at least one electrical trace of each of the radiation sensors on the first patch with the dose-reader device to determine the radiation dose amount for each of the radiation sensors.

22. A method according to claim 1, wherein transmitting is carried out wirelessly to the dose-reader device.

23. A method according to claim 1, wherein the at least one radiation sensor circuit is a plurality of radiation sensor circuits, each having a single MOSFET having an associated threshold voltage which changes when exposed to radiation and electronic memory having calibration data stored therein for a respective MOSFET, and wherein the determining step further includes the step of analyzing the change in the threshold voltage using the stored calibration data.

24. A system for monitoring radiation administered to a patient during a diagnostic and/or therapeutic treatment, the system comprises:

at least one single-use dosimeter patch, the patch comprising a substantially conformable body holding at least one radiation sensor circuit comprising a MOSFET having an associated threshold voltage that changes when exposed to radiation, and electronic memory having calibration data for determining radiation dose; and

a portable dose-reader configured to obtain voltage threshold data from the at least one patch corresponding to a dose amount of radiation exposure received during irradiation exposure,

wherein, during irradiation, the at least one patch has a perimeter that is devoid of outwardly extending lead wires.

25. A system according to claim 24, wherein the at least one patch comprises at least one tab that is configured and sized to enter a port in the dose-reader to transmit the voltage threshold data, and wherein the at least one patch is configured to determine a plurality of radiation doses received over an area of the skin of a patient during a fluoroscopic procedure.

26. A system according to claim 24, wherein the at least one patch is a plurality of spaced apart patches, each having a conformable resilient body, and wherein the reader is configured to contact each respective sensor patch to obtain the threshold voltage value associated therewith and the calibration data to determine a radiation exposure amount.

27. A system according to claim 24, wherein the at least one patch comprises a primary sensor patch and a secondary sensor patch, wherein the primary sensor patch has a larger surface area than the secondary sensor patch.

28. A system according to claim 27, wherein the primary sensor patch is configured to reside at least partially within a target radiation beam path during a fluoroscopic procedure, and wherein the secondary sensor patch is configured to reside outside the target beam path during the fluoroscopic procedure.

29. A system according to claim 27, wherein the primary sensor patch is configured to reside at least partially within a target radiation beam path during an oncology radiation treatment procedure, and wherein the secondary sensor patch is configured to reside outside the target beam path during the procedure.

30. A system according to claim 27, wherein the primary patch comprises a plurality of spaced apart radiation sensor circuits, each having a respective one MOSFET, and wherein each radiation sensor circuit MOSFET is configured to independently detect radiation.

31. A system according to claim 30, wherein each radiation sensor circuit comprises a flex circuit with at least one conductive electrical trace, and wherein the conductive electrical trace is substantially aluminum.

32. A system according to claim 31, wherein the at least one electrical trace extends from the respective radiation circuit to at least one externally accessible reader access region.

33. A system according to claim 24, wherein the electronic memory is configured to store radiation data and patient information.

34. A system according to claim 24, wherein the electronic memory comprises data corresponding to a zero temperature coefficient for radiation quantification.

35. A system according to claim 28, wherein the primary and secondary patches are packaged in a sterile kit for medical use.

36. A system according to claim 24, wherein the reader and/or at least one patch further comprises computer program code for determining radiation exposure received by a patient during a fluoroscopic procedure.

37. A system according to claim 24, wherein a lower primary surface of the patch comprises a medical grade adhesive thereon.

38. A sterile medical kit of single-use external use radiation dosimeter patches, the kit comprising:

a plurality of single-use patches, each patch comprising a generally conformable resilient substrate body comprising opposing upper and lower primary surfaces, a flex circuit with at least one radiation sensor circuit having an operational electronic component that changes a parameter in a detectable predictable manner when exposed to radiation, the flex circuit held by the substrate body, the flex circuit also including at least one electronic memory configured with radiation calibration data,

wherein, in position on a patient during radiation exposure, the dosimeter patches are devoid of externally extending lead wires, and wherein the patches are single-use dosimeter patches that adhesively secure to the skin of a patient.

39. A kit according to claim 38, wherein the patches have a lower primary surface that comprises an adhesive thereon.

40. A kit according to claim 38, wherein the disposable dosimeter patches are adapted to contact a portable reader device to electrically couple the reader device to the patch circuit.

41. A kit according to claim 38, wherein the disposable patches are configured to communicate with a portable reader device to wirelessly relay radiation data.

42. A kit according to claim 38, wherein the memory is configured to store patient specific data and radiation data.

43. A kit according to claim 38, wherein the flex circuit operational electronic component that changes a parameter in a detectable and predictable manner when exposed to radiation is an unbiased MOSFET, and wherein the patch further comprises an externally accessible tab configured to engage a portable electronic reader to transmit threshold voltage data and calibration data associated with the MOSFET.

44. A kit according to claim 38, wherein the plurality of sensor patches comprises at least one primary sensor patch and at least one secondary sensor patch, wherein the primary sensor patch has a larger surface area than the secondary sensor patch.

45. A kit according to claim 44, wherein the primary sensor patch is sized and configured to reside at least partially within a target radiation beam path during a fluoroscopic procedure, and wherein the secondary sensor patch is configured to reside outside the target beam path during the fluoroscopic procedure.

46. A kit according to claim 44, wherein the primary patch flex circuit comprises a plurality of spaced apart radiation sensor circuits, each having a respective single MOSFET that is the operational component for a respective radiation sensor circuit that changes in a detectable predictable manner when exposed to radiation, each MOSFET configured to independently detect radiation.

47. A kit according to claim 38, wherein the flex circuit comprises aluminum electrical traces.

48. A fluoroscopic single-use radiation dosimeter patch comprising a generally conformable resilient body holding at least one radiation sensor circuit with a MOSFET that changes a parameter in a detectable and predictable manner when exposed to radiation, and wherein during irradiation, the patch is devoid of externally extending lead wires.

49. A fluoroscopic dosimeter patch according to claim 48, wherein the patch has a surface area that is sufficient to cover a major portion of a predicted surface exposure area associated with a target radiation beam path, and wherein the patch comprises a plurality of spaced apart radiation sensor circuits, each having a respective MOSFET.

50. A fluoroscopic dosimeter patch according to claim 49, wherein each radiation sensor circuit comprises a single MOSFET, and wherein the radiation sensor circuits are spaced apart sufficiently to provide data for a plurality of different skin radiation exposure locations over the patch surface area.

51. A fluoroscopic dosimeter patch according to claim 50, wherein the patch is configured to provide data from each radiation sensor circuit for determining maxima, minima and average exposure over a surface area associated with the patch.

52. A fluoroscopic dosimeter patch according to claim 50, wherein the sensor patch radiation circuits are configured to detect radiation doses in the range of from about 1 to about 500 cGy.

53. A fluoroscopic dosimeter patch according to claim 52, wherein the patch is configured with a low profile when viewed from the side.

54. A fluoroscopic dosimeter patch according to claim 53, wherein the patch is substantially planar when viewed from the side.

55. A fluoroscopic dosimeter patch according to claim 49, wherein the patch has a surface area of between about 4-20 cm.

56. A fluoroscopic dosimeter patch according to claim 55, wherein the patch has a surface area of between about 8-20 cm.

57. A fluoroscopic dosimeter patch according to claim 56, wherein the patch has a surface area of between about 10-15 cm.

58. A fluoroscopic dosimeter patch according to claim 49, wherein the patch comprises a first radiation circuit with a single MOSFET that is disposed generally medially on the patch, and wherein the remainder of the radiation circuits are spaced transversely outwardly away from the first radiation circuit.

59. A fluoroscopic dosimeter patch according to claim 48, wherein the patch comprises a plurality of spaced apart radiation sensor circuits, each having a respective single MOSFET, with an increased density of the radiation sensor circuits positioned away from a generally medial location of the patch body.

60. A fluoroscopic dosimeter patch according to claim 59, wherein the patch is generally circular.

61. A fluoroscopic dosimeter patch according to claim 60, wherein a plurality of the radiation sensor circuits are circumferentially spaced apart on the patch body.

62. A fluoroscopic dosimeter patch according to claim 61, wherein a plurality of the radiation sensor circuits are radially spaced apart on the patch body.

63. A fluoroscopic dosimeter patch according to claim 48, wherein the radiation circuits each comprise at least one conductive metal trace for communicating with a portable reader after irradiation.

64. A fluoroscopic dosimeter patch according to claim 48, wherein the conductive metal traces comprise aluminum.

65. A fluoroscopic dosimeter patch according to claim 60, wherein the sensor patch has a substantially planar profile when viewed from the side.

66. A fluoroscopic dosimeter patch according to claim 48, wherein the radiation sensor circuit includes a MOSFET that is devoid of floating gate structures and/or is unpowered during radiation.