WO2024168340A1 - Transrectal probe for scintillation imaging and a method of real-time dosimetry of high-dose-rate brachytherapy - Google Patents

Abstract

A probe device having a hollow probe with an inside surface, an outside surface, an open end, a closed end, and an aperture between the open end and the closed end. A scintillating material is on the inside surface of the probe such that it is exposed through the aperture. An imaging device images an imaging window generated by the scintillating material. The images may be assessed to determine seed dosage rate, seed dwell time, seed spot position, and/or cumulative dose.

Description

TRANSRECTAL PROBE FOR SCINTILLATION IMAGING AND A METHOD OF REAL-TIME DOSIMETRY OF HIGH-DOSE-RATE BRACHYTHERAPY

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to the provisional patent application filed on February 11, 2023 and assigned U.S. App. No. 63/444,926, the disclosure of which is hereby incorporated by reference.

BACKGROUND OF THE DISCLOSURE

[0002] High and low dose rate brachytherapy (BRT) are techniques used in radiation oncology to internally treat cancers including, but not limited to prostate, cervix, breast, eye, and head and neck, with localized dose deposition. During brachytherapy, radioactive seeds are inserted via surgically placed applicators such as needles or catheters. BRT allows for optimal treatment of tumor tissue because dose deposition can be localized to the tumor site. This treatment method is often used alone or in conjunction with external beam radiation therapy, serving as a boost dosage.

[0003] High-dose rate brachytherapy (HDR BRT) treatment begins with imaging a patient to determine patient-specific anatomy as a guide for catheter placement for seed delivery. Generally, an oncologist will use ultrasound guidance to properly insert and position the catheters into the desired area to be treated. Once the catheters have been placed, medical imaging of the patient is obtained via a computerized tomography (CT) or magnetic resonance imaging (MRI) machine. These images provide a guide for a treatment plan for the positioning and delivery of multiple distributed seed dwell positions. The treatment plan determines the positioning of the seeds, the dwell time of the seeds, the dose deposition distribution, and the dose rate. During this treatment process, the CT or MRI images of the patient provide the single and final calculation of expected dose distribution. It is assumed that because the catheter placement was known prior to the implantation of the seeds, the seeds will be administered as expected and the dosage will match the original calculations.

[0004] HDR BRT further improves the therapeutic ratio by utilizing the differential response between tumor and healthy tissue via delivery with hypofractionation, delivering high doses at high dose rates. The ability to locally treat disease sites is advantageous to the radiation oncology community; however, there are unique limitations with this type of treatment not seen with external beam radiotherapy (EBRT).

[0005] Despite the promising results of various methods used for BRT, clinical implementation has historically been limited. A challenge of BRT is the lack of clinical dosimetry tools. This leads to the inability to provide dose deposition verification, making it difficult to predict, learn, and evaluate deviations from the planned dose, causing inferior patient outcomes as compared to other forms of cancer therapy. Studies have shown that BRT methods are more susceptible to delivery errors because large doses per fraction are used and seed delivery techniques are complex because of the need for multiple seed dwell times and positions for the best BRT treatment. Research has shown that brachytherapy has three times the frequency of clinically meaningful errors as compared to other types of radiation therapy techniques.

[0006] Current brachytherapy dosimetry tools include point detectors, metal-oxide- semiconductor field-effect transistors (MOSFETs), optically stimulated luminescence dosimeters (OSLDs), diodes, scintillators, and alanine diameters. These dosimetry tools are typically not successful because of the existence of large deviations between the planned and measured doses caused by the uncertainty in detector positioning. Many of the existing dosimetry tools have not been implemented in a clinical setting, further indicating the need for a dosimetry tool that could provide real-time dosimetry suitable for clinical implementation.

[0007] Using prostate HDR brachytherapy treatment as an example of the clinical workflow of BRT, treatment usually starts with correct patient identification, requiring a skilled radiation oncologist and adequate disease imaging to identify a patient whose cancer will be best treated with BRT. Many studies have investigated how BRT can best be used for treatment, either alone or as a boost dosage for EBRT, the decision of which depends on the severity of the cancer and other patient-specific considerations. With a patient selected for HDR-BRT treatment, treatment planning can begin.

[0008] Quantifying the frequency and impact of clinically-meaningful events, like brachytherapy seed misplacement, during radiation delivery could enable better understanding of the need for an in vivo dosimetry tool.

[0009] Using the patient imaging as a guide for patient-specific anatomy after the patient is prepped for surgery, the radiation oncologist surgically places applicators (needles or catheters) into the prostate. It is through these applicators that the radioactive seed(s) will be fed. Transrectal ultrasound guidance is the most used method for imaging during catheter placement. Improving the accuracy of seed placement via catheter positioning methods is an active area of research. After the catheters are placed, the patient is CT or MRI scanned again so that the radiation oncology team can plan the treatment for positioning and delivery of multiple distributed seed dwell positions based one where the catheters were placed and localized. The plan determines where the seeds will stop in the catheter (seed positioning) and how long they will be there (dwell time), both determining the dose deposition distribution and dose rate. The CT or MRI images of the patient with the placed applicators allow for a final and the only calculation of expected dose distribution, as no other dose verification method is obtained in standard of care treatment procedures. It is assumed that if the catheters placement is known, used for planning, and stable, the sources will get administered as expected and the dose will match that calculated by the treatment planning system.

[0010] Previously, a systematic review of existing in vivo dosimetry tools was performed. The review summarized reported clinical brachytherapy dosimetry trials, where most devices were point detectors, MOSFETs, OSLDs, diodes, scintillators, or alanine dosimeters. Their main limitations were the large deviations between planned and measured dose due to detector positioning uncertainties. Despite the numerous clinical trials conducted, these devices have not been brought to the clinic for use in standard procedures in BRT treatments, even when clinical trials indicate their ability to provide dose-verification information. Because of the lack of clinical-implementation in this space, estimates of uncertainty limits (e.g., source tracking uncertainty, clinical threshold for deactivation, action level alarm threshold, sensitivity, false alarm rate), detector for source tracking, position of detector for source tracking, dwell time measurements, export of dose rate, reconstruction of dose and DVH, and accumulated dose need to be improved.

[0011] Another consideration may be the advantages of real-time dosimetry, as these would allow the potential to reduce brachytherapy errors with signals to the clinical team; however, many existing devices may not be accurate and sensitive enough to be effective. Time- resolved data also has the potential to provide 3D-dose distributions and source tracking information, and existing methods are technically cumbersome. [0012] Thus, there is a need for a dosimetry tool and accompanying methods that can determine where and how much dose was deposited during brachytherapy to evaluate the treatment performed.

SUMMARY OF THE DISCLOSURE

[0013] The present disclosure provides a device and a method to enable dosimetry and understanding of seed placement, as is done with beams delivered in conventional EBRT delivery, to allow a physician to know what dose was delivered and even give the potential to stop the procedure, in the case of real-time dosimetry feedback.

[0014] The present disclosure provides a probe device that incorporates a camera and a scintillating material to provide real-time imaging and dose information during brachytherapy. The present disclosure further provides a dosimetry method for brachytherapy to assess seed dosage rate, seed dwell time, and/or seed spot position.

[0015] The present disclosure provides a device and methods that utilize scintillation imaging to provide dose information during patient treatment and beam quality assurance. Embodiments of the dosimetry technique uses an intensified CMOS camera to collect images of a scintillating material, often a scintillating sheet, during radiation delivery to the sheet/surface. The signal intensity given off from the scintillator is directly proportional to dose. In an embodiment the scintillation images can provide cumulative and frame-by-frame dose and dose rate information. This method is advantageous for its fast acquisition rate, high spatial resolution, and ability and potential to provide real-time, in vivo dose information. Embodiments of the present disclosure may also be used to verify dose information for external beam radiotherapy, but advancements in camera capabilities may extend the dosimetry technique to other radiation delivery modalities, namely BRT.

[0016] The present disclosure provides a probe device having a hollow probe with an inside surface and an outside surface, a scintillating material disposed on the inside surface of the hollow probe, and an imaging device configured to image an imaging window generated by the scintillating material. The hollow probe may have an open end and a closed end, and the hollow probe may define an aperture between the open end and the closed end. The scintillating material may be configured to be exposed through the aperture.

[0017] In an embodiment of the present disclosure, the hollow probe may be cylindrical. [0018] In an embodiment of the present disclosure, the hollow probe may be a biocompatible plastic.

[0019] In an embodiment of the present disclosure, the bio-compatible plastic may be a polycarbonate, polypropylene, polyethylene, acrylonitrile butadiene styrene (ABS), or polyacrylamide, or any other suitable polymer to provide mechanical means of inserting the hollow probe into or onto an anatomy of interest.

[0020] In an embodiment of the present disclosure, the hollow probe may have a length of 25 cm.

[0021] In an embodiment of the present disclosure, the hollow probe may have an active length of 5 cm.

[0022] In an embodiment of the present disclosure, the hollow probe may have a diameter from 1.5 cm to 2.5 cm.

[0023] In an embodiment of the present disclosure, the aperture may have a dimension from 5 cm x 0.66*pi radians.

[0024] In an embodiment of the present disclosure, the imaging device may be a camera disposed on the open end of the hollow probe.

[0025] In an embodiment of the present disclosure, the camera may be oriented at an angle relative to the hollow probe and angled to be directed toward the aperture.

[0026] In an embodiment of the present disclosure, the camera may be a CMOS camera.

[0027] In an embodiment of the present disclosure, the imaging device may be a scope lens connected to a camera. The scope lens may be disposed inside the hollow probe between the open end and the closed end, and the camera may be disposed on the open end of the hollow probe.

[0028] In an embodiment of the present disclosure, the imaging device may include one or more cameras disclosed herein.

[0029] In an embodiment of the present disclosure, the scope lens may be an endoscope lens or a laparoscopic lens.

[0030] In an embodiment of the present disclosure, the probe device may further include an ultrasound transducer disposed inside the hollow probe between the open end and the closed end. Further, the ultrasound transducer may include an ultrasound transducer lens and an ultrasound transducer electronics. Even further, the ultrasound transducer may be a laparoscopic ultrasound transducer.

[0031] In an embodiment of the present disclosure, the imaging device and the scintillating material may be configured to measure radioactive seed dose rate, seed dwell time, seed spot position, and/or cumulative dose during and/or after brachytherapy.

[0032] The present disclosure further provides a dosimetry method following implantation of radioactive seeds during brachytherapy. The method provides a probe device, a scintillating material, and an imaging device. The probe device may include a hollow probe with an inside surface and an outside surface. The hollow probe may have an open end and a closed end and define an aperture between the open end and the closed end. The scintillating material may be disposed on the inside surface of the hollow probe and configured to be exposed through the aperture. The imaging device may be configured to image an imaging window generated by a light emitted from the scintillating material during radiation delivery. The method may further include imaging the imaging window with the imaging device, and assessing at least one of the following: seed dosage rate, seed dwell time, seed spot position; or cumulative dose.

In an embodiment of the present disclosure, the light emitted from the scintillating material during radiation may be viewed using a camera.

[0033] In an embodiment of the present disclosure, the hollow probe may be inserted into a patient such that the scintillating material is flush with a tissue wall of the patient.

[0034] In an embodiment of the present disclosure, the imaging device may be a camera.

[0035] In an embodiment of the present disclosure, the imaging device may be a scope lens.

[0036] In an embodiment of the present disclosure, the imaging device may be a camera and a scope lens.

[0037] In an embodiment of the present disclosure, the scope lens may be an endoscopic lens or a laparoscopic lens.

[0038] In an embodiment of the present disclosure, the method may further include assessing a position of the hollow probe in the patient using an ultrasound transducer.

BRIEF DESCRIPTION OF THE FIGURES [0039] For a fuller understanding of the nature and objects of the disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying figures.

[0040] FIG. 1 displays an embodiment of the present disclosure, using a camera as an imaging device.

[0041] FIG. 2 displays an embodiment of the insert for the scintillating material.

[0042] FIG. 3 displays an embodiment of the hollow probe displaying the ultrasound transducer of the present disclosure.

[0043] FIG. 4 displays an example of the camera view of the scintillating material.

[0044] FIG. 5 displays an embodiment of the present disclosure, using a scope lens as the imaging device.

[0045] FIG. 6 displays an embodiment of the present disclosure including the scope lens and the ultrasound transducer.

[0046] FIG. 7 displays a cross-sectional view of an embodiment of the probe device at the connection point between a camera connected to the scope lens and the open end of the hollow probe.

[0047] FIG. 8 displays a flow diagram of an embodiment of the dosimetry method disclosed herein.

[0048] FIG. 9 displays images of probe placement and positioning.

[0049] FIGS. 10A-B displays scintillating imaging and graphical representation for detecting seed dosage and position.

[0050] FIG. 11 displays a test setup used to test embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0051] Although claimed subject matter will be described in terms of certain embodiments, other embodiments, including embodiments that do not provide all of the benefits and features set forth herein, are also within the scope of this disclosure. Various structural, logical, process step, and electronic changes may be made without departing from the scope of the disclosure. Accordingly, the scope of the disclosure is defined only by reference to the appended claims. [0052] Ranges of values are disclosed herein. The ranges set out a lower limit value and an upper limit value. Unless otherwise stated, the ranges include all values to the magnitude of the smallest value (either lower limit value or upper limit value) and ranges between the values of the stated range.

[0053] The steps of the method described in the various embodiments and examples disclosed herein are sufficient to carry out the methods of the present invention. Thus, in an embodiment, the method consists essentially of a combination of the steps of the methods disclosed herein. In another embodiment, the method consists of such steps.

[0054] The present disclosure provides a dosimetry tool for brachytherapy treatment, and specifically a scintillation imaging device. Clinical implementation of brachytherapy has historically been limited due to the complicated delivery process and its associated challenges. Scintillation imaging has the potential to overcome many of these challenges, thus improving patient outcomes.

[0055] Embodiments of scintillation imaging disclosed herein uses an intensified CMOS camera to collect images of a scintillating material, often a scintillating sheet, during radiation delivery to the sheet/surface to provide dose information during patient treatment and beam quality assurance. The signal intensity given off from the scintillator may be directly proportional to seed dose. In an embodiment, scintillation images can provide cumulative and frame-by-frame dose and dose rate information. Devices and methods utilizing scintillation techniques are advantageous for their fast acquisition rate, high spatial resolution, and ability and potential to provide real-time, in vivo dose information. It has also been used to verify dose information for external beam radiotherapy, but advancements in camera capabilities may extend the dosimetry technique to other radiation delivery modalities, namely BRT.

[0056] Currently, after brachytherapy treatment seeds or applicators are placed and their position is confirmed with imaging (e.g., CT or MRI), the patient receives treatment. It is assumed that correct dose delivery is given based on the positioning of the seeds or needles at the time of CT or MRI, which is often long before the actual treatment and seeds or needles may be subject to internal movement. There is no method of during-treatment or post-treatment patient specific dose verification. Point-detection dosimetry tools such as OSLDs, TLDs, and diode arrays have been used to verify dose delivery during treatment, but these methods only use point detectors and do not give a full-field understanding of dose distribution. These techniques also report limited data and have not gone past the clinical trial phase, meaning that dose delivery is still not verified for brachytherapy treatments. Testing has been done to demonstrate feasibility in probe geometry/camera orientation and camera ability to image scintillation intensity during HDR seed delivery with phantom materials.

[0057] The present disclosure provides the implementation of scintillation imaging for brachytherapy. As shown in FIG. 1, in an embodiment of the probe device 10, an imaging device 24, such as a camera 25, is orientated at an angle into a hollow probe 12. The camera 25 may be a CMOS camera (e.g., a FLIR PoE GigE Blacky Camera). As shown, the camera 25 is angled to be directed toward the aperture 17 of the hollow probe 12. The angle of the camera 25 relative to the hollow probe 12 can be configured for imaging. The angle may depend on the length and diameter of the hollow probe 12. The ability to angle the camera 25 provides for the accommodation of mechanical design constraints, and may depend on the specific anatomy being viewed and/or imaged with the probe device 10. For example, an embodiment of the present disclosure configured to view and/or image the rectum or prostate wall, may be shorter than an embodiment of the present disclosure to view and/or image the vaginal wall, resulting in different angles of the camera.

[0058] As shown in FIG. 1, the hollow probe 12 may be cylindrical. In an embodiment, the cylindrical hollow probe 12 may have a diameter from 1.5 cm to 2.5 cm. The hollow probe 12 may have an overall length of 25 cm and an active length of 5 cm. The overall length is the length required to insert the hollow probe 12 into the required depth of the desired anatomy. The active length is the length of the scintillating material 20 shown through the aperture 17 (FIG. 3), or the length in which the area of interest can be viewed/imaged.

[0059] Further, as shown in FIGS. 1 and 2, an embodiment of the hollow probe 12 may have a similar geometry to a rectal probe or a rectal ultrasound probe. Thus, the hollow probe 12 may be configured for ease of insertion into a patient. The hollow probe 12 may include a thin and/or flexible scintillating material 20 (e.g., Blue 800, PJ Xray, New Jersey, USA ScintillatorSheet) that is secured with a plastic encasing. The plastic encasing forms an outside surface 14 of the hollow probe 12. The hollow probe may be made from a bio-compatible plastic such as from polycarbonate, polypropylene, polyethylene, acrylonitrile butadiene styrene (ABS), polyacrylamide, or any other suitable polymer to provide mechanical means of inserting the hollow probe 12 into or onto an anatomy of interest. [0060] The scintillating material 20 is a material that exhibits scintillation, a property of luminescence. The scintillating material 20 emits light when it is excited by radiation (e g., X- rays, gamma rays, or neutrons), by absorbing the energetic radiation and converting the energy into short bursts of visible photons (such as near visible or visible light).

[0061] In embodiment of the hollow probe 12, properties of the scintillating material 20, such as wavelength emission, size, flexibility, etc., may be optimized based on the sensitivity of the imaging portion (such as camera 25) of the probe device 10, and the anatomy in which the hollow probe 12 is being inserted into. In an embodiment, the scintillating material may be in the form of a scintillating sheet. The scintillating sheet may be approximately 5 cm in length and 3 cm in width. The length of the scintillating material 20 may be determined by that of the anatomy interest, and the width of the scintillating material 20 may be determined so that the scintillating material 20 may cover, for example, half of the inside surface 13 of the hollow probe 12. In an embodiment, the scintillating material 20 may have a thickness of 0.2 mm. In an embodiment, the scintillating material 20 may be made from materials such as terbium-doped gadolinium oxysulfide (Gd2C>2S:Tb), nano-crystalline scintillator phosphors (Gd2C>2S:Pr), or crystalline Eu(II)-dopes BaFCl (BaFCTEu). The scintillating material 20 may have a maximum light emission wavelength of 380-550 nm, a relative light output of 20-200%, a decay time from 3-700 ps, and an afterglow at 3 ms of <0.1 - 1.5%. The scintillating material 20 may be made from different materials, other than what is disclosed herein. The scintillating material 20 may have different properties and parameters, other than what is disclosed herein, such as maximum light emission wavelength, relative light output, decay time, and afterglow. The properties and parameters of the scintillating material 20 depends on the anatomy of interest being viewed and/or imaged.

[0062] In embodiments of the hollow probe 12 in which the probe is used as a rectal probe, the probe may be placed into a patient’s rectum such that the scintillating material 20 (or scintillator) is flush with the rectal wall, allowing the imaging device 24, such as a camera 25 or a scope lens 27 (FIG. 6), to collect images of the light emitted from the scintillating material 20 during radiation delivery. The light fluence from the scintillating material 20 may be related to surface dose on the rectal wall to allow for real-time dose monitoring by the physician. The optical signal of the scintillating material 20 (or scintillator sheet) may be amplified to improve imaging. [0063] As shown in FIG 1, the hollow probe 12 has an inside surface 13, an outside surface 14, an open end 15, and a closed end 16. The hollow probe 12 defines an aperture 17. In an embodiment, the aperture 17 may have a dimension from 5 cm x 0.66*pi radians. The imaging device 24 connects to the open end 15 of the hollow probe 12.

[0064] FIGS. 1 and 2 display an embodiment of the probe device 10 using a camera 25 as the imaging device 24. In this embodiment, the hollow probe 12 is connected to a camera 25. The inside surface 13 of the hollow probe 12 and the aperture 17 form an insert 22 for the scintillating material 20. The scintillating material 20 can be inserted into the insert 22 through the aperture 17 and held in place by the inside surface 13 of the hollow probe 12. After the scintillating material 20 is inserted, the scintillating material 20 is disposed on either a portion of or all of the inside surface 13 of the hollow probe 12, including the length of the aperture 17. The scintillating material 20 is configured to be exposed through the aperture 17. In this embodiment, the light emitted from the scintillating material 20 during radiation generates an imaging window 32 which may be viewed and/or imaged with the imaging device 24, such as the camera 25, as shown in FIGS. 5-6.

[0065] To solve the anatomical orientation problem, which is a limitation for existing dosimetry tools, an embodiment of the hollow probe 12 may be fitted with at least one ultrasound transducer 28 including an ultrasound transducer lens 28a and ultrasound transducer electronics 28b, as shown in FIG. 3. The ultrasound transducer 28 allows localization of the hollow probe 12 during placement. In embodiments, the ultrasound transducer electronics 28b may include connection wires from an ultrasound transducer array and a control assembly. In an embodiment, the ultrasound transducer 28 may be a laparoscopic ultrasound transducer with accompanying laparoscopic ultrasound transducer electronics. This can enable dose rate, dwell time, and/or spot position inferences based on the dose information at the rectal wall, which can assist with operation of a BRT dosimetry tool. Embodiments of the present disclosure have the potential to solve many of the problems that have been identified for clinical implementation, namely high sensitivity, accuracy, and spatial localization. Embodiments of the present disclosure use full-field imaging. Through this, 2D dose information is given to the physician, as opposed to point measurements as used in existing brachytherapy dosimetry. This provides more information to the user and leads to less errors with sensitivity to positioning. [0066] FIG. 4 displays a camera view of the scintillating material 20 within the hollow probe 12. A distance of 3 cm from the camera is shown at 60, a distance of 6 cm from the camera is shown at 61, and a length of 8.5 cm from the camera is shown at 62. As shown, light is generated from irradiation that hits the scintillating material 20. The light is then captured with an imaging device, such as a camera 25 or a scope lens 27 (FIG. 6).

[0067] FIGS. 5 and 6 display an embodiment of the probe device 10, in which a scope lens 27 is used as the imaging device 24. The scope lens 27 may be an endoscope lens or a laparoscopic lens. The scope lens 27 may have any lens that is able to provide a proper field of view of the anatomy being viewed/imaged. For example, in an embodiment, a right angle orientation with a fish eye lens may be used. Further, the scope lens 27 may be positioned at the mid-point of the active length of the hollow probe 12. As shown, the scope lens 27 is disposed between the open end 15 and the closed end 16 of the hollow probe 12. The scope lens 27 is connected to a light wave carrier lens 33. This embodiment incorporates the hollow probe 12 structure, including the inside surface 13 and the outside surface 14, and scintillating material 20 insertion via the insert 22, where the scintillating material 20 can be inserted into the insert 22 through the aperture 17 and held in place by the inside surface 13 of the hollow probe 12, as shown in FIGS. 1-3.

[0068] As shown, the scope lens 27 may include a camera connection point 34 in which a camera may be connected to the scope lens 27 to take real time images of the imaging window. Further, probe device 10 may include an ultrasound readout connection point 35 to assess the localization of the hollow probe 12 through signals generated by the ultrasound transducer lens 28a and the ultrasound transducer electronics 28b.

[0069] In embodiments of the present disclosure, the light emitted from the scintillating material 20 during radiation generates an imaging window 32 which may be viewed with the scope lens 27 and imaged with the connected camera 34a. The imaging window 32 is positioned between the open end 15 and the closed end 16 of the hollow probe 12. The scope lens 27 may have a camera 34a attached to the scope lens 27 for imaging and viewing. The real image detected by the scope lens 27 may be displayed on a monitor or display device for viewing for a physician to assess seed dosage rate, seed dwell time, seed spot position, and/or cumulative dose. [0070] In embodiments of the present disclosure, the light emitted from the scintillating material 20 during radiation may be viewed and/or imaged with the camera 25 (FIGS. 1 and 2), without the use of a scope lens. In other embodiments, the camera 34a as shown in FIG. 6, may be the same camera 25 as shown in FIGS. 1-2. Embodiments may include both camera 34a and camera 25.

[0071] As shown in FIGS. 5 and 6, in an embodiment of the probe device 10, the scope lens 27 is orientated at an angle in the hollow probe 12. As shown, the scope lens 27 is angled to be directed toward the aperture 17 of the hollow probe 12. The angle of the scope lens 27 relative to the hollow probe 12 can be configured for viewing and/or imaging. The angle may depend on the length and diameter of the hollow probe 12. The ability to angle the scope lens 27 provides for the accommodation of mechanical design constraints and may depend on the specific anatomy being viewed and/or imaged with the probe device 10. For example, an embodiment of the present disclosure configured to view and/or image the rectum or prostate wall, may be shorter than an embodiment of the present disclosure to view and/or image the vaginal wall, resulting in different angles of the scope lens. Further, in an embodiment, camera 34a may be angled, as described herein.

[0072] FIG. 7 displays a cross-sectional view of an embodiment of the probe device at the connection point between the camera 34a and the open end 15 of the hollow probe 12, as shown in FIG. 6. As shown, the inside surface 13 of the hollow probe 12 includes the scope lens 27, as the imaging device, and the ultrasound transducer electronics 28b. A camera 34a may be connected to the hollow probe 12 via a camera connection point 34 (as shown in FIG. 5). The scope lens 27 may view the imaging window 32, and the camera 34a connected to the scope lens 27 may take corresponding images.

[0073] FIG. 8 displays an embodiment of a dosimetry method 100 following the implantation of radioactive seeds during brachytherapy. After the implantation of seeds during brachytherapy, an embodiment of the probe device disclosed herein may be placed into the patient to verify the seed position. The patient may be brought to an HDR bunker for treatment and the physician may attach the probe device to a HDR system. A patient lies on a table and is ready for radiation to be delivered. The physician inserts the probe device into the patient. The physician may inserts the hollow probe into the patient such that the scintillating material is flush with a tissue wall of the patient. The physician may align the portion of the hollow probe to the atomical area of interest, so that the scintillating material is in contact with the atomical area of interest. The physician may verify the probe placement via a transverse ultrasound probe or array, such as via an ultrasound transducer, such as a laparoscopic ultrasound transducer. The ultrasound transducer may allow for the direct view of the anatomy by detecting major internal structures within the patient in order to confirm the location of the probe, an example shown in FIG. 9, where 40 displays the position of the probe inserted in the patient and 41 displays the position of catheters for seed placement inserted into the patient. The probe location may be correlated to CRT/MRI imaging. The physician may leave the probe device inserted in the patient and leave the room while radiation is administered to the patient. After radiation is delivered, the physician images the light emitted from the scintillating material within the hollow probe. The physician may monitor and assess seed dosage rate, seed dwell time, seed spot position, and/or cumulative dose amounts during treatment or after treatment.

[0074] In an embodiment, images may be displayed on a calibrated intensity scale so that the brightness will be proportional to the dosage rate, seed position, and or/cumulative dose amounts, as shown in FIGS. 10A and 10B. In an embodiment, seed dosage rate, seed dwell time, seed spot position, and/or cumulative dose amounts during or after treatment may be displayed on a display device such as a computer or monitor in real time to a physician outside of a treatment bunker.

[0075] Embodiments of the present disclosure are not limited to a dosimetry method following the implantation of seeds during brachytherapy. Embodiments disclosed herein may be used to monitor dose distribution during brachytherapy.

[0076] Embodiments disclosed herein can fully characterize the dose distribution of the rectal wall. Implications of dose to other tissues can be extrapolated from these values based on known seed location and radioactivity. There is currently no clinically-implemented method for delivery dose verification via physical measurement for brachytherapy treatments because dose delivery is assumed based on the treatment planning system predicted dose distribution and CT or MRI-verified seed position. Embodiments of the present disclosure may avoid or explain mistreatments, provide physicians peace-of-mind during delivery, and provide patients with better overall care.

[0077] Dose can be determined by calibration of the scintillating material to known dose values using water equivalent phantom. Placement of the probe can be determined using an ultrasound transducer, which can enable detection of major structures as the probe is placed in the patient. For example, in an instance where the probe is inserted into a rectum, after the prostate is located, the probe location can be correlated to the CT/MRI imaging.

[0078] According to an embodiment of the present disclosure, mapping scintillation images to patient anatomy may include radio-opaque markers with fluoroscopy images to verify positioning post-placement and pre-treatment, external markers on probe indicating depth of insertion, the addition of an ultrasound transducer to the probe, the use of an ultrasound probe to gauge probe orientation pre-insertion.

[0079] While many of the examples are submitted with a rectal cancer treatment, the probe can be used with other application such as prostate cancer, gynecological cancer, or other diseases.

[0080] FIG. 11 displays an experimental test set up to test embodiments described herein. The test system was comprised of a water tank containing a water equivalent phantom 52, such as SOLID WATER ®. SOLID WATER ® mimicked true water with a water equivalence within 0.5% to support accurate calibration for radiotherapy beams, as described herein, for photon and electron energy measurements. A scintillating sheet 51 was affixed to the surface of the water equivalent phantom 52 within the tank. A radioactive source 50, such as a polarizing beam splitter (PBS) beam was directed onto the scintillating sheet. While the scintillating sheet 51 was illuminated, the camera 53, such as an iCMOS Camera, viewed and images the glowing scintillating sheet, and the results may be mapped. As shown in the graph, high spatial and temporal resolution enables the real-time dose deposition tracking, which is useful for proton delivery and ultra-high dose radiation therapy.

[0081] Although the present disclosure has been described with respect to one or more particular embodiments, it will be understood that other embodiments of the present disclosure may be made without departing from the scope of the present disclosure. Hence, the present disclosure is deemed limited only by the appended claims and the reasonable interpretation thereof.

Claims

CLAIMS:

1. A probe device comprising: a hollow probe with an inside surface and an outside surface, wherein the hollow probe has an open end and a closed end, wherein the hollow probe defines an aperture between the open end and the closed end; a scintillating material disposed on the inside surface of the hollow probe, wherein the scintillating material is configured to be exposed through the aperture; and an imaging device configured to image an imaging window generated by the scintillating material.

2. The probe device of claim 1, wherein the hollow probe is cylindrical.

3. The probe device of claim 1, wherein the hollow probe is a bio-compatible plastic.

4. The probe device of claim 3, wherein the bio-compatible plastic is polycarbonate, polypropylene, polyethylene, acrylonitrile butadiene styrene (ABS), or polyacrylamide

5. The probe device of claim 1, wherein the hollow probe has a diameter from 1.5 cm to 2.5 cm.

6. The probe device of claim 1, wherein the aperture has a dimension from 5 cm x 0.66*pi radians.

7. The probe device of claim 1, wherein the imaging device is a camera disposed on the open end of the hollow probe.

8. The probe device of claim 7, wherein the camera is oriented at an angle relative to the hollow probe and angled to be directed toward the aperture.

9. The probe device of claim 7, wherein the camera is a CMOS camera.

10. The probe device of claim 1, wherein the imaging device is a scope lens connected to a camera, and wherein the scope lens is disposed inside the hollow probe between the open end and the closed end and the camera is disposed on the open end of the hollow probe.

11. The probe device of claim 10, wherein the scope lens is an endoscope lens or a laparoscopic lens.

12. The probe device of claim 1, further comprising an ultrasound transducer disposed inside the hollow probe between the open end and the closed end.

13. The probe device of claim 1, wherein the imaging device and the scintillating material are configured to measure radioactive seed dose rate, seed dwell time, seed spot position, and/or cumulative dose.

14. A dosimetry method following implantation of radioactive seeds during brachytherapy comprising: providing a probe device including: a hollow probe with an inside surface and an outside surface, wherein the hollow probe has an open end and a closed end, wherein the hollow probe defines an aperture between the open end and the closed end; a scintillating material disposed on the inside surface of the hollow probe, wherein the scintillating material is configured to be exposed through the aperture; and an imaging device configured to image an imaging window generated by a light emitted from the scintillating material during radiation delivery; imaging the imaging window with the imaging device; and, assessing at least one of the following: seed dosage rate; seed dwell time; seed spot position; or cumulative dose.

15. The method of claim 14, wherein the hollow probe is inserted into a patient such that the scintillating material is flush with a tissue wall of the patient.

16. The method of claim 14, wherein the imaging device is a camera.

17. The method of claim 14, wherein the imaging device is a scope lens.

18. The method of claim 14, wherein the imaging device is a camera and a scope lens.

19. The method of claim 17, wherein the scope lens is an endoscope lens or a laparoscopic lens.

20. The method of claim 14, further comprising assessing a position of the hollow probe in the patient using an ultrasound transducer.