PSD sensors for head and neck

Abstract

A radio-opaque plastic scintillator detector (PSD) for use in various head and neck radiation applications is described. Bite plates, nose cones and ear cones are provided for use therewith, each having hollow tubes into which PSD cables can be inserted for real time measurement of radiation during treatment.

Claims

1. A device comprising: a bite plate comprising a housing and at least one conduit within the housing; wherein the bite plate housing is configured to be shaped to fit in a human mouth; and at least one scintillating radiation sensor cable; wherein the at least one scintillating radiation sensor cable is configured to be placed within the conduit.

2. The device of claim 1, wherein the bite plate housing further comprises a substantially U-shaped base.

3. The device of claim 2, wherein the bite plate housing further comprises at least one outer rim.

4. The device of claim 3, wherein the bite plate housing further comprises a lingual portion.

5. The device of claim 4, wherein the at least one conduit may extend within one of the following: the substantially U-shaped base; the at least one outer rim; or the lingual portion.

6. The device of claim 1, wherein the bite plate further comprises an extraoral base.

7. The device of claim 6, wherein the extraoral base is configured to be connected to a radiation mask.

8. The device of claim 1, wherein the at least one scintillating radiation sensor cable comprises a diameter up to 1 mm.

9. The device of claim 8, wherein the at least one scintillating radiation sensor cable is configured for real-time radiation monitoring.

10. A device comprising: a cone comprising a housing and at least one conduit within the housing; wherein the cone housing is configured to be shaped to fit in a human nose or ear; and at least one scintillating radiation sensor cable; wherein the at least one scintillating radiation sensor cable is configured to be placed within the conduit.

11. The device of claim 10, wherein the cone housing is inflatable.

12. The device of claim 11, wherein the cone further comprises an inflation lumen.

13. The device of claim 10, wherein the cone housing is comprised of a compressible foam material.

14. The device of claim 10, wherein the cone housing further comprises a distal end and a proximal end and is configured to flare from the distal end towards the proximal end.

15. The device of claim 10, wherein the at least one scintillating radiation sensor cable is configured for real-time radiation monitoring.

16. A device comprising: a housing and at least one conduit within the housing; wherein the housing is configured to be shaped to fit in any of the following human orifices: a mouth, a nose, or an ear; and at least one scintillating radiation sensor cable; wherein the at least one scintillating radiation sensor cable is configured to be placed within the conduit.

17. The device of claim 16, wherein the housing further comprises a substantially U-shaped bite plate.

18. The device of claim 16, wherein the housing further comprises an inflatable element.

19. The device of claim 16, wherein the housing further comprises a foam plug.

20. The device of claim 16, wherein the at least one scintillating radiation sensor cable is configured for real-time radiation monitoring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) A better understanding of the present invention can be obtained with the following detailed descriptions of the various disclosed embodiments in the drawings:

(2) FIG. 1A shows a perspective view of an oral sensor device from the mouthpiece side.

(3) FIG. 1B shows a perspective view of FIG. 1A from the extraoral side.

(4) FIG. 1C is a top view of FIG. 1A.

(5) FIG. 1D is a side view of the device of FIG. 1A.

(6) FIG. 1E shows a perspective view of an alternate embodiment of FIG. 1A, lacking the lingual area and lingual sensors.

(7) FIG. 2A shows a perspective view of a dual arch embodiment from the mouthpiece side.

(8) FIG. 2B shows a perspective view of FIG. 2A from the extraoral side.

(9) FIG. 2C is a top view of FIG. 2A.

(10) FIG. 3A is a perspective view of a nosepiece embodiment.

(11) FIG. 3B is a cross section of the device of FIG. 3A through line A-A.

(12) FIG. 4A is a side view of another nosepiece embodiment.

(13) FIG. 4B is a perspective view of a 4A from the bottom, looking up at sensor conduits.

(14) FIG. 4C is a cross section of the device of FIG. 4A through line A-A.

(15) FIG. 5A is a side view of another nosepiece embodiment.

(16) FIG. 5B is a perspective view of FIG. 5A from the bottom, looking up at sensor conduits.

(17) FIG. 5C is a cross section of the device of FIG. 5A through line A-A.

(18) FIG. 6A-B. A perspective view of a PSD sensor showing enlargement area A in FIG. 6B.

(19) FIG. 7A-B Side and top views of a PSD sensor showing enlargement area B and C.

(20) FIG. 8A-B are enlargement views of area B of sensor end of PSD cable.

(21) FIG. 9 enlargement view C of SC connector end of PSD cable.

(22) FIG. 10 Dosing graphic.

(23) FIG. 11A Top view of completed dual arch mouthpiece, with extended hollow tubes ending in Tuohy Borst adaptors. FIG. 11B side view, 11C perspective view, and 11D end view of same device. The parts are otherwise the same as in FIG. 2 and only the new portions are labeled.

(24) FIG. 12A Top view of completed single arch mouthpiece, with extended hollow tubes ending in Tuohy Borst adaptors. FIG. 12B side view, 12C perspective view, and 12D end view of same device.

(25) FIG. 13A top view of completed earpiece, with extended hollow tube ending in Tuohy Borst adaptors. FIG. 13B perspective view of same.

(26) FIG. 14A top view of dual sensor nose or earpiece, 14B perspective and 14C end views.

(27) FIG. 15A depicts a top view of another embodiment of a dual sensor nose or earpiece, FIG. 15B depicts a side view of the embodiment of FIG. 15A, FIG. 15C depicts a perspective view of the embodiment of FIG. 15A, and FIG. 15D depicts an end view of the embodiment of FIG. 15A.

DETAILED DESCRIPTION OF THE INVENTION

(28) Turning to FIG. 1, a sensor-containing mouthpiece 100 that is generally U-shaped for oral use is shown in several views. FIG. 1A shows a perspective view from the mouthpiece side, 1B a perspective view from the extraoral side, 1C a top view, and 1D a side view.

(29) The U-shaped base 101 allows contact with the occlusal surfaces of teeth, and rims or edges contact teeth. Obviously, this bite plate is sized and shaped for human use, and can be made available in a range of sizes (S, M, L, XL).

(30) The buccal (cheek) surfaces of the mouth are contacted by outer rim 105 and the lingual surface of the teeth by inner rim 103, but either or both can be omitted depending on where sensor placement is desired. In this particular embodiment, the lingual area 108 is filled in so that sensor can be placed to measure radiation at the tongue, but this is optional, depending on which area is to be treated. The U-shaped base 101 has an extraoral component 109, that functions to provide connection to e.g., a radiation face mask, which is typically employed for external beam radiation of the head and neck. Connectors such as screw 113 and nut 111, are shown, however, other connectors are possible.

(31) Tubes 107A, 107B and 107C provide conduits for the PSD sensors to be housed, thus allowing real-time radiation monitoring of radiation to the mouth, tongue and jaw area. The conduits continue proximally from the bite plate 101 to a connector, not shown for clarity. However, these features are seen in the diagrams of FIG. 11-15. The PSD sensor cables are inserted into these hollow tubes, again not shown for clarity, but an example is shown in FIG. 13 and the PSD sensors connect via adaptors to the photodetector. For clarity, distal and proximal are with reference to the technician, not the patient. Thus, the bite plate is distal, and the photodetector is proximal.

(32) Placement and number of sensor conduits can vary, but here we showed paired sensors 107A on the buccal rims 105, paired sensors under the mouthpiece 107B, and paired sensors 107C inside the lingual area 108. For clarity, the sensors are not shown inside these tubes 107, but they are small cables of 0.5-1 mm in diameter, ending in a PSD sensor, as described previously.

(33) FIG. 1E shows the device of FIG. 1A, but lacking the lingual area 108.

(34) FIG. 2A-D is a dual arch sensor-containing mouthpiece 200. It is similar to the single arch design, but has upper and lower rims so that both arches (maxillary and mandibular) can be monitored at the same time with PSD sensors.

(35) With references to FIG. 2A-D, the U-shaped base 201 allows contact with the occlusal surfaces of teeth, and rims or edges contact teeth. The buccal surfaces are contacted by upper outer rim 205T and lower outer rim 205B and the lingual surface by upper inner rim 203T and lower inner rim 203B. Lingual area 208 allows one or more sensors to be placed lingually to measure radiation at the tongue. The U-shaped base 201 has an extraoral component 209, having screw 213 and nut 211, however, other connectors are possible.

(36) Tubes 207A, 207B, 207C and 207D provide conduits for the PSD sensors to be housed, thus allowing real-time radiation monitoring of radiation to the mouth, tongue and jaw area. Paired sensors 207A on the upper buccal rims 205T, paired sensors 207B on the lower buccal rims 205B, paired sensors under the mouthpiece 207C, and paired sensors 207D inside the lingual area 208. This arrangement of sensors is exemplary only, and other arrangements are possible.

(37) FIG. 3A-B shows a sensor-containing nosepiece embodiment 300 having a conical head 301 that is sized and shaped to fit an human nostril, and can be made available in a range of sizes (S, M, L, XL). The cone is gently rounded for comfort, and flared proximately to prevent accidental ingress. Blind conduit 303 holds sensor 305 with PSD 307 at the tip. Note that the tip 307 is shown somewhat larger, but this is for clarity only and it is usually minimally larger or the same diameter as the rest of the PSD cable.

(38) Rather than providing a range of sizes, FIG. 4A-C shows a sensor nosepiece or earpiece 400 that is inflatable. Cone 401 is attached to lumen or tube or hollow cylinder 403. Cone 401 is made of a semi-compliant or compliant polymeric film that can be inflated, thus fitting any human nostril. Cylinder 403 has at least two conduits407 for the sensor(s) and 408 for inflation of cone 401. The inflation conduit 408 is fluidly connected to an interior of cone 401 such that the interior can be inflated. The other end of conduit 408 has a luer lock 411 or other valve means to control fluid ingress and egress. Conduits 407, herein shown a pair of conduits, can be closed, such that no air escapes therethrough. Here we show the distal end of conduits 407 closed (e.g., bind conduits), but other options are possible.

(39) FIG. 5A-C shows yet another sensor nose or ear embodiment, wherein cone 501 is made of soft flexible foam, such as is used in earplugs. Since the foam is very malleable, this device can be used for nostrils or ears. A pair of conduits 503 houses the PSD sensors (not shown), but the number and placement of conduits 503 can vary.

(40) FIG. 6-9 show the cable as assembled by one possible method. In these figures, 1 is the scintillator fiber that has been dipped in a tantalum bath. A preferred scintillator fiber is a 0.5 mm BCF-60 by St Gobain with emission at 530 nm.

(41) The plastic optic fiber or POF 2 is a Mitsubishi ESKA, POF Simplex, 0.5 mm core with opaque jacket, but other POFs may be suitable. Polymer optical fiber has a concentric double-layer structure with high-purity polymethyl methacrylate (known as PMMA) core and specially selected transparent fluorine polymer cladding. The cladding has a lower refractive index than that of the core. This special structure efficiently retains the light power inside the cable.

(42) POF 2 is connected to the scintillator fiber 1 via epoxy 4, and supported in close juxtaposition by tube 7. Here we have used a polyimide tube, but any suitable tube could be used. In order to assemble these components, the POF 2 jacket is stripped at the end, leaving a 0.5-1.5 inch segment of naked POF fiber 2B. Tube 7 is then fit over this naked end.

(43) Next, about 0.1-1 l, preferably about 0.2 l of epoxy is placed on the sides of scintillator, and the cut scintillator fiber also inserted into the tube, gently guiding it to come to rest against the cut POF end. Any optically transparent epoxy can be used, but we have selected EPO-TEK 301, a low viscosity, low temperature cured (65 C./1 hour), optically clear, two component epoxy adhesive. This adhesive previously passing the standard ISO10993 testing, has now successfully passed the more extensive testing of 12 weeks implantation.

(44) Typically a small amount (0.5-2 mm) of scintillator fiber protrudes from the end of the tube, but this is not essential and is a matter of convenience of assembly.

(45) Once the senor end is assembled, it is dipped into an opaque polymeric material to block light. Preferably this material also provides some strength or stiffening, and as such acts to protect the delicate sensor tip.

(46) Connector 6 is added to the proximal end of the POF cable by known means. We have selected an SC connector (SFP-WDM-155M-20A LC by Elpa), which has a data rate of 100/155 Mbit/s, wavelength 1480-1580 nm, peak at 1310 nm, a sensitivity of 28 dBm, and power output 14 dBm minimum to 8 dBm maximum, with an input maximum at 8 dBm. However, there are many suitable connectors and the connector will vary with the photodetector employed to read the signal.

(47) If the POF core is 0.5 mm, the whole cable must be at least 0.6 mm with the various coatings thereon, but can be as much as 1 mm. It is still small enough, however, to be used in in vivo applications, even on a urinary catheter, which is quite small.

(48) Any suitable photodetector can be used with the above sensor, including those base on silicon photomultipliers (SiPMs), photomultiplier tubes, PIN photodiodes, multicolor cameras, monochromatic cameras, avalanche photodiode (APD); charge-coupled devices (CCD), and the like. Selection may vary with the applicationthe PIN, APD and PMT have higher sensitivity, suitable for low dose rate and out-of-field dose monitoring. PMT's relative uncertainty remains under 1% at the lowest dose rate achievable (50 Gy/s), suggesting optimal use for live dosimetry. For dose rate above 3 mGy/s, the PIN diode is the most effective photodetector in term of performance/cost ratio. For lower dose rate, such as those seen in interventional radiology, PMTs are the optimal choice. See also Ser. No. 15/135,576, filed Apr. 22, 2016, and 62/150,852, filed Apr. 22, 2015, entitled MONOLITHIC PHOTODIODE DETECTOR FOR DOSIMETER.

(49) In use, a plan of the optimal distribution of the radiation sources is developed by the treating radiologist, and by using the sensor containing embodiments of the invention, the dose can be more accurately monitored, and hopefully the device and sensor usage will allow the use of smaller treatment volumes (FIG. 10).

(50) FIG. 11-15 show completed prototypes without the sensors therein, wherein the hollow tubes extend proximally beyond the body of each device (11207, 12207, 13207, 14207, 150207), and each terminates in an adaptor (11200, 12200, 13200, 14200, 150200), that allows the sensor to be locked in place inside the hollow tube, herein shown Tuohy adaptors, but other valves could be used, such as luer locks, clamps, etc. Parts that are not labeled in these figures, are seen and discussed in the figures above.

(51) FIG. 13A also shows the PSD sensor cable 13300 inserted into the hollow tube 13207 and having its own adaptor 13400, e.g., SMA adaptor, for connecting to a photodetector 13500.

(52) In use the patient is prepped, the sensors loaded into the sensor conduits and the Tuohy tightened to lock the sensor in place. The sensor devices are then placed orally, nasally or aurally, as appropriate. For those devices that are inflatable, the next step is inflation to the desired level. The proximal end of the sensor cable is then connected to a photodetector. Although the devices could be integral, separate devices allow the cables to be changed when damaged.

(53) If the sensor device or PSD tip is coated with e.g., tantalum or has any radio-opaque markers thereon, it can be imaged before treatment, to ensure reproducible positioning over the course of treatment, and if needed the device position can be adjusted. Position should also be recorded for use in the next treatment session. Once correctly positioned, the PSD cables that protrude from the device can be held in place against the skin using e.g., adhesive tape or clamps to prevent them from moving. If desired, further imaging can be performed to guide detailed treatment planning.

(54) The images of the patient with the applicators in situ are imported into treatment planning software. The treatment planning software enables multiple 2D images of the treatment site to be translated into a 3D virtual patient, within which the position of the sensors can be defined. The spatial relationships between the treatment site and the surrounding healthy tissues within this virtual patient are a copy of the relationships in the actual patient.

(55) To identify the optimal distribution of radiation beams or radiation sources, the treatment planning software allows virtual radiation to be placed within the virtual patient. The software shows a graphical representation of the distribution of the irradiation. This serves as a guide for the radiotherapy team to refine the distribution of the beams or sources and provide a treatment plan that is optimally tailored to the anatomy of each patient before actual delivery of the irradiation begins. This approach is sometimes called dose-painting. Herein, dose painting can be greatly improved with real-time feedback about delivered radiation.

(56) Once the patient prepped, sensor in place, and imaging completed, treatment can commence, and dosimetry can be measured on a real-time basis at targeted locations via the PSD sensors within the applicator. Adjustments to positioning and/or total dosage or delivery rates can be made based on this real-time feedback, and the adjustments can be applied immediately, or in the next treatment session, as appropriate. Once the desired dosage level is reached for a given treatment session, the treatment is stopped. This can be repeated as often as necessary to target the tumor.

(57) On completion of delivery of the radiation in a given session, the devices are disconnected from the photodetector. The balloon (if any) is deflated, and the device is carefully removed from the body. Patients typically recover quickly from the procedure, enabling it to often be performed on an outpatient basis.

(58) The term distal as used herein is the end of the device inserted into the body cavity, while proximal is opposite thereto and is closest to the medical practitioner deploying the device. The terms top and bottom are in reference to the figures only, and do not necessarily imply an orientation on usage. The length of applicator plus handle and cables is the longitudinal axis, while a horizontal axis and vertical axis cross the longitudinal axis, and the cross sections are shown across the longitudinal axis.

(59) As used herein the GTV or gross tumor volume is what can be seen, palpated or imaged.

(60) As used herein CTV or Clinical Target Volume is the visible (imaged) or palpable tumor plus any margin of subclinical disease that needs to be eliminated through the treatment planning and delivery process.

(61) The third volume, the planning target volume or PTV, allows for uncertainties in planning or treatment delivery. It is a geometric concept designed to ensure that the radiotherapy dose is actually delivered to the CTV.

(62) Radiotherapy planning must always consider critical normal tissue structures, known as organs at risk (OAR). In some specific circumstances, it is necessary to add a margin analogous to the PTV margin around an OAR to ensure that the organ cannot receive a higher-than-safe dose; this gives a planning organ at risk volume.

(63) As used herein, a cold spot is a decrease of dose to an area significantly under the prescribed dose. While there is no hard fast rule as to what quantifies a cold spot, numbers greater than 10% below prescription should be scrutinized. A hot spot is the opposite, an area receiving >10% over prescription.

(64) As used herein, fractionation refers to radiation therapy treatments given in daily fractions (segments) over an extended period of time, sometimes up to 6 to 8 weeks.

(65) By inflation herein what is mean is inflation to the recommended pressure level, thus the volume will vary according to the size of the device, but typically range from 4-7 cc, or about for a nostril balloon, and 1-3 for an ear balloon.

(66) By radio-opaque what is meant is a material that obstructs the passage of radiant energy, such as x-rays, the representative areas appearing light or white on the exposed film. In preferred embodiments, the devices are asymmetrically marked with a radio-opaque material such that placement and orientation can be reproducibly achieved with every treatment.

(67) By summation shadow what is meant is when parts of a patient or an object in different planes are superimposed. The result is a summation image representing the degree of X-Ray absorption by all the superimposed objects. Radiolucent summation shadows are formed in the Swiss cheese effect. Radiopaque summation shadows are involved in the bunch of grapes effect.

(68) By silhouette effect what is meant is the fact that when two structures of the same radiopacity are in contact, their individual margins at the point of contact cannot be distinguished. One is said to silhouette with the other, or to form a positive silhouette sign.

(69) By blind tube, we mean that one end (usually the distal end inside the device) is closed, such that air cannot escape through said hollow tube.

(70) The use of the word a or an when used in conjunction with the term comprising in the claims or the specification means one or more than one, unless the context dictates otherwise.

(71) The term about means the stated value plus or minus the margin of error of measurement or plus or minus 10% if no method of measurement is indicated.

(72) The use of the term or in the claims is used to mean and/or unless explicitly indicated to refer to alternatives only or if the alternatives are mutually exclusive.

(73) The terms comprise, have, include and contain (and their variants) are open-ended linking verbs and allow the addition of other elements when used in a claim. The term consisting of is a closed linking verb, and does not allow the addition of other elements.

(74) The term consisting essentially of occupies a middle ground, allowing non-material elements to be added. In this case, these would be elements such as marking indicia, radio-opaque markers, a stopper, packaging, instructions for use, labels, and the like.

(75) The following abbreviations may be used herein:

(76) TABLE-US-00001 ABS Acrylonitrile butadiene styrene ADP Avalanche photodiode APBI Accelerated partial breast irradiation CCD Charge-coupled devices CRT Conformal radiation therapy CT Computer tomography CTV Clinical Target Volume. DVH Dose-volume histogram EBRT External beam radiation therapy, sometimes XRT GTV Gross tumor volume HDR High dosage rate IGRT Image guided radio therapy IMRT Intensity-modulated radiation therapy IV Irradiated volume LDR Low dosage rate MPPC Multipixel photon counter MRI magnetic resonance imaging OAR Organ at risk PCB Printed circuit board PDR Pulsed dosage rate PEEK Polyether ether ketone PET position emission tomography or polyethylene terephthalate PIN P-type semiconductor-intrinsic semiconductor-n-type semiconductor region. PIN diode is a diode with a wide, undoped intrinsic semiconductor region between a p-type semiconductor and an n-type semiconductor region. PMT Photomultiplier tubes (photomultipliers for short), vacuum phototubes are extremely sensitive detectors of light in the ultraviolet, visible, and near-infrared ranges of the electromagnetic spectrum. These detectors multiply the current produced by incident light by as much as 100 million times (i.e., 160 dB), in multiple dynode stages, enabling (for example) individual photons to be detected when the incident flux of light is low. POF Plastic optic fiber PRV Planning organ-at-risk volume PTV Planning target volume PVC Poly vinyl chloride RVR Remaining volume at risk SiPM Silicon photomultiplier, see also MPPC TV Treated volume XRT radiation therapy

(77) The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the details of the illustrated apparatus and system, and the construction and method of operation may be made without departing from the spirit of the invention.

(78) Each of the following is incorporated by reference herein in its entirety for all purposes: Boivin, J. et al., Systematic evaluation of photodetector performance for plastic scintillation dosimetry, Med. Phys. 42(11): 6211-6220 (2015). Lessard, F., et al., Validating plastic scintillation detectors for photon dosimetry in the radiologic energy range, Med Phys. 39(9): 5308-5316 (2012). Wootton L. & Beddar, S., Temperature dependence of BCF plastic scintillation detectors, Phys Med Biol. 58(9): 10.1088/0031-9155/58/9/2955 (2013). US20140221724, US20140221724, U.S. Pat. No. 8,735,828 REAL-TIME IN VIVO RADIATION DOSIMETRY USING SCINTILLATION DETECTOR by Beddar Ser. No. 15/135,576, filed Apr. 22, 2016, and 62/150,852, filed Apr. 22, 2015, entitled MONOLITHIC PHOTODIODE DETECTOR FOR DOSIMETER US20100288934, US20140018675, US20150216491, U.S. Pat. Nos. 9,028,390, 9,351,691, APPARATUS AND METHOD FOR EXTERNAL BEAM RADIATION DISTRIBUTION MAPPING by Keppel US20060173233 BRACHYTHERAPY APPLICATOR FOR DELIVERY AND ASSESSMENT OF LOW-LEVEL IONIZING RADIATION THERAPY AND METHODS OF USE by Lovoi WO2003062855 METHOD AND APPARATUS FOR REAL TIME DOSIMETRY by Rosenfeld US20100318029 SEMI-COMPLIANT MEDICAL BALLOON U.S. Pat. No. 4,584,991 MEDICAL DEVICE FOR APPLYING THERAPEUTIC RADIATION US20150335913 BRACHYTHERAPY APPLICATOR DEVICE FOR INSERTION IN A BODY CAVITY 61/481,503, filed May 2, 2011, Ser. No. 13/444,584 (now U.S. Pat. No. 8,885,986), filed Apr. 11, 2012, Ser. No. 14/470,707 (now U.S. Pat. No. 8,953,912), filed Aug. 27, 2014 SMALL DIAMETER RADIATION SENSOR CABLE 62/049,258, filed Sep. 11, 2014, and Ser. No. 14/849,790 (pending), SKIN PATCH DOSIMETER 62/063,196 filed Oct. 13, 2014, Ser. No. 14/881,023, filed on Oct. 12, 2015 (pending); URINARY RADIATION SENSOR CATHETER