Single-use internal dosimeters for detecting radiation in fluoroscopy and other medical procedures/therapies

• US 7,491,942 B2
• Filed: 06/10/2004
• Issued: 02/17/2009
• Est. Priority Date: 11/30/2001
• Status: Active Grant

• Current Assignee: SNC Holdings Corp.
• Original Assignee: Sicel Technologies, Inc.
• Inventors: Widener, Steven R., Mann, Gregory Glenwood, Lehman, Phillip M., Black, Robert D., Carroll, John
• Primary Examiner(s): Porta; David P
• Assistant Examiner(s): Taningco; Marcus H
• Application Number:
  US10/865,312
• Publication Number:
  US 20050010110A1
• Time in Patent Office: 1,713 Days
• Field of Search: 250/370.07
• US Class Current: 250/370.07
• 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 internal dosimeters with MOSFETs into a patient to evaluate the radiation dose delivered during a medical procedure or treatment session. The MOSFETs can be unpowered during irradiation.

Claims

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

inserting a single-use dosimeter into a patient, wherein the at least one dosimeter comprises at least one radiation sensor circuit with a MOSFET and electronic memory that holds calibration data for the MOSFET;

exposing the patient to radiation in a medical procedure during a treatment session;

transmitting data from the dosimeter to a dose-reader device after the exposing step, the transmitting data comprising the calibration data and data associated with a change in an operational parameter in the MOSFET of the dosimeter radiation sensor circuit;

removing the dosimeter from the patient after the exposing step during or proximate in time to the treatment session; and

determining a radiation dose received by the patient during the exposing step based on the change in the operational parameter of the MOSFET and the calibration data.

2. A method according to claim 1, wherein the at least one radiation sensor circuit includes a single operative MOSFET that is unbiased and unpowered during irradiation.

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

4. A method according to claim 1, further comprising transmitting the determined radiation dose from the dose-reader to the at least one dosimeter and storing the determined radiation dose on the electronic memory that is integrated with the at least one dosimeter.

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

6. A method according to claim 1, further comprising sterilizing the single-use dosimeter and packaging the single-use dosimeter in a sterile package suitable for human medical use.

7. A method according to claim 1, wherein the at least one dosimeter is held in and/or on a mouthpiece, and wherein the inserting step comprises placing the mouthpiece in the mouth of the patient.

8. A method according to claim 7, wherein the mouthpiece is a bite block that includes an outwardly extending tab portion, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory.

9. A method according to claim 1, wherein the at least one dosimeter is held in a generally conformable nose cavity plug, and wherein the inserting step comprises inserting the plug into a nasal cavity.

10. A method according to claim 9, wherein the nose cavity plug includes an outwardly extending tab portion, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory after the exposing step.

11. A method according to claim 1. wherein the at least one dosimeter is held in a generally conformable ear plug, and wherein the inserting step comprises inserting the plug into an ear canal or cavity of the patient.

12. A method according to claim 11, wherein the ear plug includes an outwardly extending tab portion, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory after the exposing step.

13. A method according to claim 12, wherein the at least one dosimeter is configured such that at least one dosimeter is held by two different ear plugs, and wherein the step of inserting comprises inserting the plugs into both a right and a left ear canal of the patient.

14. A method according to claim 1, wherein the at least one dosimeter is held in and/or on a flexible male genourinary catheter.

15. A method according to claim 14, wherein the dosimeter comprises a flex circuit with a MOSFET held at a distal end portion of the catheter and an external outwardly extending tab portion located at a proximal end portion of the catheter, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory after the exposing step.

16. A method according to claim 14, wherein the inserting step is carried out so that the MOSFET in at least one of the at least one radiation sensor circuit is disposed proximate a prostate of a male patient.

17. A method according to claim 16, wherein the exposing step is carried out during brachytherapy or external radiation beam therapy.

18. A method according to claim 1, wherein the at least one dosimeter is held in and/or on a flexible female genourinary probe.

19. A method according to claim 18, wherein the at least one dosimeter is held in a vaginal probe.

20. A method according to claim 18, wherein the at least one dosimeter is held in a urethral probe.

21. A method according to claim 18, wherein the at least one dosimeter includes an outwardly extending tab portion, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory after the exposing step.

22. A method according to claim 1, wherein the at least one dosimeter is held in or on a rectal probe.

23. A method according to claim 22, wherein the rectal probe includes an outwardly extending tab portion, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory after the exposing step.

24. A method according to claim 1, wherein the exposing step is carried out during a high-dose rate brachytherapy using a plurality of catheters having an open end to slidably receive the dosimeter, the catheters held in a transcutaneous geometric matrix with a radioactive Ir-192 source that travels in the open catheters into the patient, and wherein the inserting step comprises placing the dosimeter inside at least one of the open catheters.

25. A method according to claim 24, wherein the dosimeter includes an outwardly extending tab portion, and wherein the transmitting data step comprises engaging a portable reader with the tab portion to electronically engage the reader with the radiation sensor circuit and the electronic memory after the exposing step.

26. A method according to claim 1, wherein the at least one dosimeter is a plurality of dosimeters spaced apart in a lengthwise direction, each having a respective radiation sensor circuit with a single operative MOSFET, and wherein the determining step comprises determining a radiation dose for each of the radiation sensor circuits to provide a plurality of dose readings at different internal depths associated with the exposing step.

27. A method according to claim 1, further comprising positioning at least one substantially conformable skin-mounted single-use dosimeter patch on the patient, the at least one surface mount dosimeter patch comprising a flex circuit with a radiation sensor circuit having an unbiased MOSFET and electronic memory configured to hold calibration data for the radiation sensor circuit.

28. A method according to claim 27, further comprising transmitting data from the at least one surface mount patch to the dose-reader device after the exposing step to obtain the calibration data and data associated with a change in an operational parameter in the MOSFET of the dosimeter radiation sensor circuit to determine radiation received by the patient during the exposing step based on the change in the operational parameter of the MOSFET and the calibration data.

29. A method according to claim 1, wherein the transmitting step further comprises electronically transmitting measurement methodology instructions to the reader from the dosimeter on how to communicate with the dosimeter.

30. A method according to claim 29, further comprising storing the determined radiation dose in the memory of the dosimeter after the determining step.

31. A method according to claim 1, wherein the transmitting step further comprises transmitting a type of internal dosimeter the dosimeter is to the reader.

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

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

a portable dose-reader configured to obtain voltage threshold data and calibration data from the at least one internal dosimeter after the single-use dosimeter has been exposed to radiation corresponding to a dose amount of radiation exposure received during irradiation exposure.

33. A system according to claim 32, wherein the at least one internal dosimeter comprises at least one contact region that is configured and sized to enter a port in the dose-reader to transmit the voltage threshold data and the calibration data.

34. A system according to claim 32, wherein the dose reader is sized and configured as a handheld and/or pocket-sized portable reader.

35. A system according to claim 32, wherein the dose-reader is configured to obtain data from the internal dosimeter and from a substantially conformable single-use skin mounted dosimeter patch and determine radiation dose at a monitored location of the patient from each type of dosimeter.

36. A system according to claim 32, wherein the internal dosimeter is sized and configured as a natural body lumen and/or cavity probe.

37. A system according to claim 36, wherein the internal dosimeter is integrated in and/or on a mouthpiece.

38. A system according to claim 37, wherein the reader further comprises a computer readable storage medium having computer readable program code embodied in the medium, the computer readable program code comprising computer program code for identifying what type of dosimeter is undergoing evaluation from a plurality of differently configured dosimeters configured to be evaluated by the dose reader.

39. A system according to claim 38, wherein the reader comprises a computer readable storage medium having computer readable program code embodied in the medium, the computer readable program code comprising computer program code that prompts a user to identify the dosimeter configuration being evaluated.

40. A system according to claim 38, wherein the reader automatically identifies the type of dosimeter based on data in the electronic memory of the dosimeter.

41. A system according to claim 37, wherein the mouthpiece is a bite block that includes an externally extending tab portion, and wherein the tab portion is configured to electronically engage the reader with the radiation sensor circuit and the electronic memory.

42. A system according to claim 36, wherein the internal dosimeter is configured as a generally conformable nose cavity plug.

43. A system according to claim 42, wherein the nose cavity plug includes a tab portion that is configured to engage the portable reader to electronically engage the reader with the radiation sensor circuit and the electronic memory.

44. A system according to claim 36, wherein the internal dosimeter is configured as a generally conformable ear plug.

45. A system according to claim 44, wherein the ear plug includes an outwardly extending tab portion that is configured to electronically engage the portable reader with the radiation sensor circuit and the electronic memory.

46. A system according to claim 36, wherein the probe is a catheter, and wherein the at least one dosimeter is held in and/or on a flexible male genourinary catheter.

47. A system according to claim 46, wherein the dosimeter comprises a flex circuit with a MOSFET held at a distal end portion of the catheter and a tab portion located at a proximal end portion of the catheter that is configured to electronically engage the portable reader with the radiation sensor circuit and the electronic memory.

48. A system according to claim 46, wherein the at least one dosimeter is a plurality of dosimeters each having an associated radiation sensor circuit with a MOSFET, the dosimeters configured so that the MOSFETS are held spaced apart in a lengthwise direction on a flex circuit, and wherein the catheter comprises an expandable balloon that expands above a male urinary sphincter and holds the catheter in position during irradiation so that the MOSFET in at least one of the at least one radiation sensor circuits is configured to reside proximate a prostate of a male patient above the urinary sphincter.

49. A system according to claim 48, wherein the flex circuit is configured to be slidably received in the catheter to allow in situ axially adjustable placement of at least one of the radiation sensor circuits.

50. A system according to claim 48, wherein the dosimeter is configured to obtain radiation data during brachytherapy and/or external radiation beam therapy.

51. A system according to claim 36, wherein the at least one dosimeter is held in and/or on a flexible female genourinary probe.

52. A system according to claim 51, wherein the probe is configured as a vaginal probe.

53. A system according to claim 51, wherein the probe is configured as a urethral probe.

54. A system according to claim 51, wherein the dosimeter includes a tab portion configured to engage the portable reader to electronically engage the reader with the radiation sensor circuit and the electronic memory.

55. A system according to claim 36, wherein the dosimeter configured as a rectal probe.

56. A system according to claim 55, wherein the rectal probe includes an outwardly extending tab portion configured to electronically engage a portable reader with the radiation sensor circuit and the electronic memory.

57. A system according to claim 32, wherein the internal dosimeter is sized and configured as a transcutaneous probe.

58. A system according to claim 57, wherein the at least one dosimeter is sized and configured to be received in at least one of a plurality of catheters having an open end and being held in a transcutaneous geometric matrix during HDR (high dose rate) brachytherapy to provide radiation dose estimates of a radioactive source that travels in the open catheters into the patient.

59. A system according to claim 58, wherein the dosimeter includes an outwardly extending tab portion configured to engage a portable reader to electronically engage the reader with the radiation sensor circuit and the electronic memory, wherein the dosimeter is self-contained and unpowered during exposure to radiation.

60. A system according to claim 32, wherein the at least one dosimeter is a plurality of dosimeters held spaced apart in a lengthwise direction on a common flex circuit in a common probe body, each having a respective radiation sensor circuit with a single operative MOSFET, wherein the different dosimeters are configured to provide radiation data for a plurality of axially spaced apart subsurface depth locations.

61. A system according to claim 32, wherein the calibration data comprises data associated with a zero temperature coefficient of the MOSFET for radiation quantification.

62. A system according to claim 32, wherein the electronic memory is configured to store radiation data and patient information.

63. A system according to claim 32, wherein the at least one dosimeter is biocompatible and sterilized and held in a package for medical use.

64. A system according to claim 32, wherein the reader comprises computer program code for prompting a clinician to enter calibration data associated with a particular patient and medical procedure and computer program code for determining radiation exposure received by the patient whereby the reader can calculate the radiation dose for both a surface dosimeter and at least one internal dosimeter.

65. A system according to claim 64, wherein the reader comprises computer program code for prompting a user to select the type of radiation dosimeter being evaluated from a predetermined list of dosimeter types including external and internal dosimeter configurations.

66. An internal dosimeter according to claim 32, wherein the dosimeter is sized and configured to be slidably received in at least one of a plurality of catheters having an open end and held in a transcutaneous geometric matrix during HDR (high dose rate) brachytherapy to provide radiation dose estimates of a radioactive source that travels in the open catheters into the patient.

67. An internal dosimeter according to claim 66, wherein the dosimeter includes an outwardly extending tab portion that defines the reader contact zone and is configured to enter a port in the portable reader to electronically engage the reader with the radiation sensor circuit and the electronic memory.

68. An internal dosimeter according to claim 67, wherein the dosimeter comprises a plurality of radiation sensor circuits on a common flex circuit, each circuit having a respective single operative MOSFET with each MOSFET held spaced apart in a lengthwise direction on the dosimeter and being configured to provide dose data associated with a plurality of different internal depth locations.

69. A system according to claim 32, wherein the dosimeter memory includes instructions to tell the reader how to electronically communicate with the dosimeter.

70. A system according to claim 32, wherein the reader is configured to calculate the radiation dose and transmit the calculated radiation dose to the dosimeter memory for electronic storage.