Design and fabrication of patient-specific radiation therapy collimator holders

Abstract

Patient-specific collimator holders are designed and constructed for use with radiation therapy methods, such as minibeam radiation therapy or other spatially fractionated radiation therapies. The patient-specific collimator holders can be placed directly on the patient to reduce errors in radiation dose delivery when the patient moves during treatment.

Description

DESIGN AND FABRICATION OF PATIENT-SPECIFIC RADIATION THERAPY COLLIMATOR HOLDERSBACKGROUND

[0001] Minibeam radiation therapy is a form of spatially fractionated radiation therapy with the potential to offer increased tumor control, lower radiation damage to healthy tissues, and potentiate anti-tumor immune responses in patients. In clinical use, x-ray sources are used for treatment delivery; however, these x-ray sources generally have low dose rates, which increases treatment times. Minibeam radiation therapy uses a tungsten collimator with submillimeter wide slits to spatially separate the radiation beam into individual, narrow planar beams. With increased treatment times there is a potential for patient movement which would reduce or eliminate the unique spatial characteristics of the radiation as the patient moves relative to the collimator.SUMMARY OF THE DISCLOSURE

[0002] It is an aspect of the present disclosure to provide a method for creating a patient-specific collimator holder for a radiation therapy treatment. The method includes receiving, using a computing device, 3D imaging data. A 3D volume of a patient is generated from the 3D imaging data. A region-of-interest (ROI) for receiving radiation therapy within the 3D volume of the patient is determined. Using the computing device, a 3D model of a collimator holder is generated from the 3D volume of the patient and the ROI. The 3D model has an inner surface that conforms to an exterior surface of the 3D volume. The 3D model of the collimator holder is then output using the computing device. Other embodiments of this aspect include corresponding systems (e.g., computer systems), programs, algorithms, and / or modules, each configured to perform the steps of the methods.

[0003] It is another aspect of the present disclosure to provide a patient-specific collimator holder for use in minibeam radiation therapy. The patient-specific collimator holder includes a body extending from a first surface to a second surface opposite the first surface, where the second surface conforms to an exterior surface of a portion of a patient adjacent a region-of-interest (ROI) that is to receive minibeam radiation therapy. The exterior surface of the patient includes skin of the patient. An aperture is directed through the body of the collimator holder. The aperture corresponds to the shape and the size of the ROI that is to receive radiation therapy, and aligns with at least a portion of the ROI when the collimatorholder is interfaced with the exterior surface of the patient. A slot is formed in the body of the patient-specific collimator holder and sized to receive a collimator.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a flowchart of an example method for designing and manufacturing a patient-specific collimator holder.

[0005] FIGS. 2A-2G are example patient-specific collimator holders.

[0006] FIGS. 3A and 3B show additional examples of patient-specific collimator holders and corresponding 3D models of the collimator holders.

[0007] FIGS. 4A-4C show an example of a generating a patient-specific collimator holder relative to patient anatomy and a tumor target. A) A 3D volume and surface rendering of a patient (in lateral decubitus position) along with the target (in green) is created from a CT scan. A square structure representing the 12 x 12 cm2tungsten collimator is shown in the appropriate position for treatment. B) Digital rendering of the 3D printed collimator holder in position on the patient. The portion which contacts the patient is Boolean subtracted from the body surface to conform exactly to the patient’s anatomy. C) Closeup view of the 3D printed collimator holder showing labels which indicate orientation and anatomic location. The photo shows the actual collimator holder with the 12 x 12 cm2tungsten collimator in place.

[0008] FIG. 5 shows another example of a patient-specific collimator holder relative to patient anatomy and a tumor target (shown in green).

[0009] FIG. 6 shows a block diagram of an example 3D printing system.

[0010] FIG. 7 shows a block diagram of an example system for designing a patientspecific collimator holder in accordance with some embodiments described in the present disclosure.

[0011] FIG. 8 is a block diagram of example components that can implement the system of FIG. 7.DETAILED DESCRIPTION

[0012] Described here are systems and methods for designing and constructing patientspecific radiation therapy collimator holders. These patient-specific collimator holders can be placed directly and secured to on the patient, thereby addressing the problem of patient movement during minibeam radiation therapy. With the collimator holder attached to the patient, when the patient moves the collimator moves with them. In this way, the spatiallyseparated beams from the minibeam radiotherapy treatment will remain in the same location relative to the patient and would not blur out. Advantageously, the designed collimator holder will conform exactly to the patient’s unique body shape, which also allows for improved comfort and functionality. Although described in relation to minibeam radiation therapy, the collimator holders described in the present application can also be adapted for use with other external beam radiation therapy systems, including microbeam radiation therapy systems, other spatially fractionated radiation therapy systems, and so on.

[0013] To overcome challenges associated with microbeam radiation therapy, minibeam radiation therapy has been proposed. The difference in spatial dimensions can be similar between microbeams and minibeams, though minibeams are wider (e.g., > 500 microns) and generally have a larger center-to-center spacing than microbeams (e.g., > 1000 microns). While these slightly larger dimensions reduce the peak doses that can be safely delivered, minibeams offer many of the same benefits as microbeams including excellent normal tissue sparing, tumor control, and immunomodulation. Advantageously, due to their larger size and spacing, minibeams are less vulnerable to blurring with physiologic motion, which allows for the use of conventional x-ray sources. The disclosed systems and method improve upon minibeam radiation therapy treatments by reducing effects of patient or physiological motion during treatment using the collimator holders described in the present disclosure.

[0014] It is an advantage of the present disclosure to enable the design and construction of patient-specific collimator holders with a semi-automated design process. In some aspects, the disclosed systems and methods decrease the lead time to generate collimator holders after a patient receives radiological imaging and dosimetric planning. This is advantageous for destination medical centers to improve patient care by enabling a shorter stay and enables personalized treatment of time-sensitive cases that could previously not be aided by such methods.

[0015] It is another aspect of the present disclosure to decrease the required software proficiency of engineering to complete required tasks. Creation of models and guides typically require hundreds of steps ensuring accurate parameters and order of operations that can be automated with scripting including complex multi-step operations to reliably achieve desired output. The disclosed systems and methods can be implemented with a simpler workflow, thereby increasing user adoption.

[0016] In still other aspects, the disclosed systems and methods decrease human error in creation of related forms. An incorrect parameter at any point in a design process may result in deviation from true anatomy or improper fit of the therapeutic device, creating risk for the patient and liability for the institution. Advantageously, the automation used by the disclosed systems and methods removes a large fraction of potential sites of error, as well as mistakes made as a result of designer fatigue.

[0017] It is a further advantage of the disclosed systems and methods to increase standardization in the design process between users and institutions. Standardized design features ensure greater accuracy and consistency.

[0018] Referring now to FIG. 1. a flowchart is illustrated as setting forth the steps of an example method 100 for designing and constructing a patient-specific collimator holder. As described above, the collimator holder will advantageously conform to the surface of the patient and surround a tumor region that is to receive radiation treatment, such as minibeam radiation therapy.

[0019] The method includes receiving imaging data of the patient using a computing device, as indicated at step 102. Receiving the imaging data can include accessing the imaging data with the computing device by retrieving the imaging data from a memory or other data storage device or medium. Alternatively, receiving the imaging data can include acquiring the imaging data with a medical imaging system and transferring or otherwise communicating the imaging data to the computing device, which in some instances may be a part of the medical imaging system.

[0020] The imaging data may include, for example, computed tomography (CT) images acquired from the patient using a CT system. In some cases, the imaging data can be 3D imaging data (e.g., 3D CT imaging data). The imaging data can be of a portion of the patient that is to receive minibeam radiation therapy treatment. For example, the imaging data can be of a head of a patient, an extremity of the patient, etc. In some instances, the imaging data may include segmented medical images, such as medical images of the patient that have been segmented to identity tumor regions, organs-at-risk. and other regions of the patient or patient anatomy.

[0021] The computing device generates a 3D volume of the patient from the imaging data, as indicated at step 104. The 3D volume includes a region of the patient that is to receive minibeam radiation therapy. Thus, this 3D volume can be can various portions of the patient including a head of the patient, an extremity of the patient (e.g., an arm, a leg. etc.), etc. Insome embodiments, after the 3D volume of the patient has been generated, the 3D volume can be manipulated, changed, etc. For example, the computing device can receive a user input (e.g., from a user interacting with the computing device) that can truncate the 3D volume of the region of the patient (e.g., remove a portion that is not needed), adjust (e.g., smooth) surfaces of 3D volume, bridge voids or other artifacts in the 3D volume, etc.

[0022] The computing device determines a region-of-interest of the 3D volume that is to receive the minibeam radiation therapy, as indicated at step 106. In some cases, the ROI includes identifiable features, such as peripheral outlines of a superficial tumor and thus the computing device can identify and mark the outline of the ROI to contour these peripheral outlines of the superficial tumor. In other cases, such as when there are no easily identifiable features, the computing device can receive a user input that identifies the ROI on the 3D volume. In some cases, this ROI can be an enclosed surface on the 3D volume, or a perimeter of that enclosed surface.

[0023] As indicated at step 108, the computing device generates a 3D model of a collimator holder according to the 3D volume of the patient and the determined ROI. The 3D model of the collimator holder can be generated by starting with a 3D model of an unmodified collimator holder (e.g., a collimator holder template model) and then removing material from the 3D model to define a patient facing surface of the collimator holder that will conform to the 3D volume of the patient and / or the determined ROI.

[0024] The 3D volume of the patient, the 3D volume of the ROI (e.g.. tumor, target), and a 3D model of the collimator to be used with the collimator holder can be exported as DICOM RT structures and imported into a suitable software module to create the 3D model of the collimator holder. Additionally, an indication of the desired holder opening direction and any special instructions (e.g., painful areas on the patient skin to avoid contact) can be provided and used as an input when designing the 3D model of the collimator holder.

[0025] The 3D model of the collimator holder may be sent to a radiation oncologist for approval. When approved, final 3D model of the collimator holder can be exported for printing, as described below.

[0026] As a non-limiting example, the following process can be used to generate the 3D model of the collimator holder. The 3D volume of the patient, the 3D volume of the ROI, and the model of the proposed collimator in position are received by the computing device. A graphical user interface (GUI) can prompt the user to select the collimator part, identify its size (e.g.. 7 cm or 12 cm) based on the object volume, and import the associated internally-developed geometry (e.g., solid blank collimator holder). A low-resolution collimator can be evaluated for inertial axes to determine the large planar surfaces of the object. The center of the plane on the collimator closest to the patient is used as a reference point to place an analytical reference plane (datum plane), resized to match the x-y dimensions of the collimator. The view is oriented normal to this plane and the user can be prompted via the GUI to rotate the datum plane into alignment with the collimator. Another datum plane is generated at a know n position relative to the imported blank. A plane-to-plane alignment of the fixed plate (collimator datum plane) and moving plane (imported blank datum plane) is then performed while moving a duplicate of the blank into a coincident position. The collimator holder blank has an open end used to slide the collimator into the holder. In some instances, the opening position can be provided as a user input as mentioned above (e.g., defined by a radiation oncologist via screenshot and annotation when submitting the request). The GUI can instruct the user to rotate the blank by 90 degree increments to match this annotation with specific settings that keep the end collimator position static. A Boolean subtraction of the selected body from the collimator holder blank is performed. The user can be prompted to complete undercut removal if it is determined that the body geometry would create undercuts preventing fit. The GUI can instruct the user to label the part with unique identifier, anatomic orientation, and fiducials for dimensional verification.

[0027] Additional quality controls can be incorporated into the 3D model of the collimator holder. As one example, quality controls can include checking for collision between the final collimator holder part and the patient body or tumor. Additional speed improvements can include automating initial user rotation of the planes to match the collimator.

[0028] The 3D model of the collimator holder can span a surface of the 3D volume of the patient that is larger than a surface of the 3D volume that includes the ROI. In other words, such as when the ROI is a (superficial) tumor, the surfaces (e g., interior surface and exterior surface) of the 3D model of the collimator holder are larger than the surface of the tumor. In some cases, the 3D model of the collimator holder can be created by defining the outlines of a surface of the 3D volume of the patient and extruding this surface of the 3D volume of the patient by a thickness. In some embodiments, the entire interior surface of the 3D model of the collimator holder partially (or entirely) contours the exterior surface of the 3D volume. In this way, the exterior surface of the collimator holder, when created, can easily interface with the desired portion of the patient.

[0029] In some embodiments, generating the 3D model of the collimator holder includes creating an aperture through the 3D model of the collimator holder. In some cases, the computing device, based on the determined region of interest, can determine a size and a shape of the aperture. In some cases, the peripheral edges of the aperture align exactly with the peripheral edges of the ROI (e.g., a superficial tumor). In this way, when the collimator holder is constructed and interfaced on the patient, the entire aperture of the collimator holder aligns exactly with a target region that is to receive radiation therapy (e.g., the target region on the patient corresponding to the ROI on the 3D volume). In some cases, the aperture directed through the collimator holder can be larger than the ROI (e.g., the ROI being enclosed by the aperture). In this case, the peripheral edges of the aperture can have a shape that is identical or substantially similar (e.g., deviating by less than 20% of identical) to the ROI. or the peripheral edges of the aperture can have a shape that is different than the ROI. For example, the aperture can have a typical geometric shape (e.g., a square, rectangle, circle, oval, etc.), while the ROI can have peripheral edges that define an amorphous shape (e.g., for a tumor). In some configurations, having the aperture larger than the area of the ROI can ensure that the entire target region (e.g., tumor) is treated by the radiation therapy beam.

[0030] In some configurations, the 3D model of the collimator holder can be generated to span entirely (or partially) over a supporting anatomical structure. For example, the supporting anatomical structure can include a structure that provides stability for the collimator holder, thereby mitigating movement between the collimator holder and the patient when the collimator holder is interfaced with the patient. Thus, the supporting anatomical structure can include the nose (e.g., a bridge of the nose), ajoint (e.g., the shoulder), etc.

[0031] Examples of collimator holder models that can be generated using the methods described in the present disclosure are illustrated in FIGS. 2A-2G. FIGS. 2A and 2B illustrate example collimator holder blanks (i.e., unmodified collimator holders) sized to receive a 7 cm collimator (FIG. 2A) or a 12 cm collimator (FIG. 2B). Each collimator holder 200 includes a body 202 extending from a first surface 204 to a second surface 206. In general, the second surface 206 will come into contact with the patient and, therefore, may be referred to as a patient-facing surface. A central aperture 208 extends through the body 202 of the collimator holder. A slot 210 is formed in the body 202 of the collimator holder 200 near the first surface 204. The slot 210 is sized to receive the respective collimator for use with the collimator holder (e.g., a 7 cm collimator, a 12 cm collimator, etc.).

[0032] FIGS. 2C and 2D illustrate 12 cm collimator holders 200 that have been designed to conform to a surface of two different patients. FIG. 2E illustrates a 7 cm collimator holder 200 that has been designed to conform to a surface of a patient. Different volumes of the collimator holder blanks have been removed to conform to both the respective 3D patient volume and 3D ROI volume.

[0033] FIG. 2F illustrates an example collimator holder 200 that includes a support element 212 that extends away from an exterior sidewall of the collimator holder 200. This support element 212 can span over a supporting anatomical structure. FIG. 2G illustrates an example collimator holder 200 that includes support elements 214 extending away from the patient-facing surface 206 of the collimator holder 200. These support elements 214 help accommodate the tumor volume while maintaining contact with the patient surface and supporting the collimator holder in the desired treatment position.

[0034] FIGS. 3A and 3B illustrate examples of collimator holder models (left) and the corresponding manufactured collimator holders (right). FIGS. 4A-4C illustrate another example of a 3D model of a collimator model and corresponding collimator positioned relative to a 3D volume of a patient and a 3D volume of an ROI (e.g., target tumor). FIG. 5 illustrates another example of a 3D model of a collimator model positioned relative to a 3D volume of a patient and a 3D volume of an ROI (e.g., target tumor). The example collimator holder illustrated in FIG. 5 includes a support element extending from an exterior side wall of the collimator holder to span over a supporting anatomical structure (e.g.. a portion of the patient's torso).

[0035] As indicated at step 110, the computing device can transmit the 3D model to an additive manufacturing system, such as a 3D printing system. In some cases, this can include transmitting the entire computed aided design (CAD) file, transmitting build instructions generated from or otherwise based on the 3D model, or transmitting other simplified models. In some cases, a computing device can transmit, along with the 3D model for example, 3D printing parameters that are to be utilized by the 3D printer system when constructing the collimator holder from the 3D model of the collimator holder. For example, these 3D printing parameters can include a bed (or build platform) temperature, a nozzle temperature, an infill percentage, a nozzle speed, a layer height (e.g., of a single 2D deposited pattern), a nozzle diameter, an infill pattern, an extrusion multiplier (e.g., the flow rate of extrudable material through the extruder), a type of extrusion material that is to be used (e.g., a biocompatible resin filament), combinations thereof, and so on.

[0036] The computing device causes the 3D printer system to construct the collimator holder from the 3D model of the collimator holder, as indicated at step 112. In some cases, the 3D printer system can utilize the received 3D printing parameters and use them while printing the collimator holder, or ensure that they pass the desired parameters.

[0037] In some cases, the 3D printer system can construct the collimator holder using vat photopolymerization 3D printing with a biocompatible resin. Vat photopolymerization can be advantageous due to printing and post processing speed and end part dimensional accuracy. As another non-limiting example, powder bed fusion can be used for manufacturing the collimator holder.

[0038] The build material used for constructing the collimator holder can include biocompatible materials such as a biocompatible resin, nylon, or the like. As one example, the build material may be Biomed Amber resin or PA2200 (Nylon 12). The material Biomed Amber can be advantageous for its prevalence in current clinical use, sterilizability, translucency, and third party validated biocompatibility of the material in Class 2 medical devices. Translucency allows visual confirmation of proper collimator insertion. The mass of the parts has been deemed acceptable by patients, and the completed collimator holder can be sterilized and / or cleaned between uses.

[0039] Post processing cleaning, curing, and support removal can occur prior to tapping holes with 4-48 tap and insertion of spring plunger hardware used to hold the collimator in place.

[0040] In some embodiments, after the collimator holder has been constructed, an adhesive layer can be applied to the interior surface of the collimator holder (e.g., the patient contacting surface of the collimator holder that contacts an exterior surface of the patient). Additionally, a backing can be placed on the adhesive layer (e.g., a plastic backing) to ensure that the adhesive layer is protected (e g., while transporting the collimator holder). The adhesive layer can help secure the collimator holder to the patient and ensure the collimator holder does not move during the radiation treatment.

[0041] FIG. 6 shows a schematic illustration of an example 3D printing system 600. The 3D printing system 600 can include a computing device, or controller, 602 in communication with a positioning system 604. The positioning system 604 can include a build platform 606 and an extruder 608. The positioning system 604 can move the extruder 608 relative to the build platform 606 in order to fabricate an object 610 while the extruder 608 deposits build material. In some cases, the build platform 606 can be a rigid and planar surfaceon which the object 610 is fabricated in a build volume 612. Although shown with one extruder 608, the 3D printing system 600 can alternatively include two extruders, or may include more than two extruders. Advantageously, a 3D printing system 600 with two extruders allows for the fabrication of objects, such as the collimator holders described in the present disclosure, using more than one build material type. Alternatively, both extruders in a dual-extruder configuration could be configured to deposit the same build material type.

[0042] The extruder 608 includes a chamber 614 in an interior thereof to receive a build material (e.g., a filament, such as a biocompatible resin filament, a nylon filament, etc.), and the extruder 608 can include an extrusion tip 616 that extrudes build material. In some cases, the extruder 608 can include a heating element 618 to melt the biocompatible resin filament or other build material within the chamber 614 for extrusion through the extrusion tip 616 in liquid form. In some cases, the extruder 608 can also include a motor 620 to force the build material through the chamber 614 and through the extrusion tip 616.

[0043] As one example of operation, a build material such as a biocompatible resin filament can be fed into the chamber 614 from a spool or the like by the motor 620, melted by the heating element 618, and extruded from the extrusion tip 616. By controlling a rate of the motor 620, the temperature of the heating element 618, other process parameters, or combinations thereof, the build material can be extruded, which can impact the overall shape of the object 610.

[0044] The positioning system 604 can be generally adapted to three-dimensionally position the extruder 608 and the corresponding extrusion tip 616 such that the extruder 608 deposits build material in accordance with a previously computed object design (e.g., a 3D model of the collimator holder). In general, the object 610 may be fabricated by depositing successive layers of build material in two-dimensional patterns determined by the computed object design.

[0045] The 3D printing system 600 can be operated under the control of the computing device 602 that is in communication, such as wired or wireless communication, with the positioning system 604 including the build platform 606, and other components of the 3D printing system 600. In general, the computing device 602 is operable to control the components of the 3D printing system 600, such as the build platform 606, extruder 608, and positioning system 604 to fabricate the object 610 from the suitable build materials. The computing device 602 can include any combination of software, processing circuitry’, or both suitable for controlling the various components of the 3D printing system 600. As an example.the controller may include a microprocessor, microcontroller, application-specific integrated circuit (ASIC), programmable gate arrays, and any other digital or analog components. In some embodiments, the computing device 602 can be a processor associated with a personal computer or other computing device that is in communication with the 3D printing system 600. Thus, in some embodiments the computing device 602 can be configured or otherwise programmed to perform the processes described herein.

[0046] FIG. 7 shows an example of a system 700 for designing a patient-specific collimator holder in accordance with some embodiments described in the present disclosure. As shown in FIG. 7, a computing device 750 can receive one or more types of data (e.g., imaging data, collimator model data, user input data) from data source 702. In some embodiments, computing device 750 can execute at least a portion of a patient-specific collimator holder design system 704 to generate a 3D model of a patient-specific collimator holder from data received from the data source 702.

[0047] Additionally or alternatively, in some embodiments, the computing device 750 can communicate information about data received from the data source 702 to a server 752 over a communication network 754, which can execute at least a portion of the patient-specific collimator holder design system 704. In such embodiments, the server 752 can return information to the computing device 750 (and / or any other suitable computing device) indicative of an output of the patient-specific collimator holder design system 704.

[0048] In some embodiments, computing device 750 and / or server 752 can be any suitable computing device or combination of devices, such as a desktop computer, a laptop computer, a smartphone, a tablet computer, a wearable computer, a server computer, a virtual machine being executed by a physical computing device, and so on. The computing device 750 and / or server 752 can also transmit the 3D model of the patient-specific collimator holder to a 3D printing system 600 or other suitable additive manufacturing or other manufacturing system.

[0049] In some embodiments, data source 702 can be any suitable source of data (e.g., measurement data, images reconstructed from measurement data, processed image data), such as an imaging system, another computing device (e.g., a server storing measurement data, images reconstructed from measurement data, processed image data), and so on. In some embodiments, data source 702 can be local to computing device 750. For example, data source 702 can be incorporated with computing device 750 (e.g.. computing device 750 can be configured as part of a device for measuring, recording, estimating, acquiring, or otherwisecollecting or storing data). As another example, data source 702 can be connected to computing device 750 by a cable, a direct wireless link, and so on. Additionally or alternatively, in some embodiments, data source 702 can be located locally and / or remotely from computing device 750, and can communicate data to computing device 750 (and / or server 752) via a communication network (e.g., communication network 754).

[0050] In some embodiments, communication network 754 can be any suitable communication network or combination of communication networks. For example, communication network 754 can include a Wi-Fi network (which can include one or more wireless routers, one or more switches, etc.), a peer-to-peer network (e.g., a Bluetooth network), a cellular network (e.g., a 3G network, a 4G network, etc., complying with any suitable standard, such as CDMA. GSM, LTE, LTE Advanced. WiMAX, etc.), other types of wireless network, a wired network, and so on. In some embodiments, communication network 754 can be a local area network, a wide area network, a public network (e.g., the Internet), a private or semi -private network (e.g., a corporate or university intranet), any other suitable type of network, or any suitable combination of networks. Communications links shown in FIG. 7 can each be any suitable communications link or combination of communications links, such as wired links, fiber optic links, Wi-Fi links, Bluetooth links, cellular links, and so on.

[0051] Referring now to FIG. 8, an example of hardware 800 that can be used to implement data source 702, computing device 750, and server 752 in accordance with some embodiments of the systems and methods described in the present disclosure is shown.

[0052] As shown in FIG. 8, in some embodiments, computing device 750 can include a processor 802, a display 804, one or more inputs 806, one or more communication systems 808, and / or memory 810. In some embodiments, processor 802 can be any suitable hardware processor or combination of processors, such as a central processing unit (CPU), a graphics processing unit (GPU), and so on. In some embodiments, display 804 can include any suitable display devices, such as a liquid crystal display (LCD) screen, a light-emitting diode (LED) display, an organic LED (OLED) display, an electrophoretic display (e.g., an “e-ink’‘ display), a computer monitor, a touchscreen, a television, and so on. In some embodiments, inputs 806 can include any suitable input devices and / or sensors that can be used to receive user input, such as a keyboard, a mouse, a touchscreen, a microphone, and so on.

[0053] In some embodiments, communications systems 808 can include any suitable hardware, firmware, and / or software for communicating information over communication network 754 and / or any other suitable communication networks. For example, communicationssystems 808 can include one or more transceivers, one or more communication chips and / or chip sets, and so on. In a more particular example, communications systems 808 can include hardware, firmware, and / or software that can be used to establish a Wi-Fi connection, a Bluetooth connection, a cellular connection, an Ethernet connection, and so on.

[0054] In some embodiments, memory' 810 can include any suitable storage device or devices that can be used to store instructions, values, data, or the like, that can be used, for example, by processor 802 to present content using display 804, to communicate with server 752 via communications system(s) 808, and so on. Memory 810 can include any suitable volatile memory, non-volatile memory, storage, or any suitable combination thereof. For example, memory 810 can include random-access memory’ (RAM), read-only memory’ (ROM), electrically programmable ROM (EPROM), electrically erasable ROM (EEPROM), other forms of volatile memory, other forms of non-volatile memory, one or more forms of semivolatile memory’, one or more flash drives, one or more hard disks, one or more solid state drives, one or more optical drives, and so on. In some embodiments, memory' 810 can have encoded thereon, or otherwise stored therein, a computer program for controlling operation of computing device 750. In such embodiments, processor 802 can execute at least a portion of the computer program to present content (e.g., images, user interfaces, graphics, tables), receive content from server 752, transmit information to server 752, and so on. For example, the processor 802 and the memory 810 can be configured to perform the methods described herein (e.g.. the method 100, or steps thereof, of FIG. 1).

[0055] In some embodiments, server 752 can include a processor 812, a display 814, one or more inputs 816, one or more communications systems 818, and / or memory' 820. In some embodiments, processor 812 can be any suitable hardware processor or combination of processors, such as a CPU, a GPU, and so on. In some embodiments, display 814 can include any suitable display devices, such as an LCD screen, LED display, OLED display, electrophoretic display, a computer monitor, a touchscreen, a television, and so on. In some embodiments, inputs 816 can include any suitable input devices and / or sensors that can be used to receive user input, such as a keyboard, a mouse, a touchscreen, a microphone, and so on.

[0056] In some embodiments, communications systems 818 can include any suitable hardware, firmware, and / or software for communicating information over communication network 754 and / or any other suitable communication networks. For example, communications systems 818 can include one or more transceivers, one or more communication chips and / or chip sets, and so on. In a more particular example, communications systems 818 can includehardware, firmware, and / or software that can be used to establish a Wi-Fi connection, a Bluetooth connection, a cellular connection, an Ethernet connection, and so on.

[0057] In some embodiments, memory 820 can include any suitable storage device or devices that can be used to store instructions, values, data, or the like, that can be used, for example, by processor 812 to present content using display 814, to communicate with one or more computing devices 750, and so on. Memory 820 can include any suitable volatile memory, non-volatile memory, storage, or any suitable combination thereof. For example, memory 820 can include RAM, ROM, EPROM, EEPROM, other types of volatile memory, other ty pes of non-volatile memory7, one or more types of semi-volatile memory, one or more flash drives, one or more hard disks, one or more solid state drives, one or more optical drives, and so on. In some embodiments, memory 820 can have encoded thereon a server program for controlling operation of server 752. In such embodiments, processor 812 can execute at least a portion of the server program to transmit information and / or content (e.g., data, images, a user interface) to one or more computing devices 750, receive information and / or content from one or more computing devices 750, receive instructions from one or more devices (e.g., a personal computer, a laptop computer, a tablet computer, a smartphone), and so on.

[0058] In some embodiments, the server 752 is configured to perform the methods described in the present disclosure. For example, the processor 812 and memory7820 can be configured to perform the methods described herein (e.g.. the method 100, or steps thereof, of FIG. 1).

[0059] In some embodiments, data source 702 can include a processor 822, one or more inputs 824, one or more communications systems 826, and / or memory7828. In some embodiments, processor 822 can be any suitable hardware processor or combination of processors, such as a CPU, a GPU, and so on. In some embodiments, the one or more inputs 824 are generally configured to acquire data, images, or both, and can include an imaging system, such as a CT system, a magnetic resonance imaging (MRI) system, or other suitable medical imaging system. Additionally or alternatively, in some embodiments, the one or more inputs 824 can include any suitable hardware, firmware, and / or software for coupling to and / or controlling operations of the imaging system. In some embodiments, one or more portions of the input(s) 824 can be removable and / or replaceable.

[0060] Note that, although not shown, data source 702 can include any suitable inputs and / or outputs. For example, data source 702 can include input devices and / or sensors that can be used to receive user input, such as a keyboard, a mouse, a touchscreen, a microphone, atrackpad, a trackball, and so on. As another example, data source 702 can include any suitable display devices, such as an LCD screen, an LED display, an OLED display, an electrophoretic display, a computer monitor, a touchscreen, a television, etc., one or more speakers, and so on.

[0061] In some embodiments, communications systems 826 can include any suitable hardware, firmware, and / or software for communicating information to computing device 750 (and, in some embodiments, over communication network 754 and / or any other suitable communication networks). For example, communications systems 826 can include one or more transceivers, one or more communication chips and / or chip sets, and so on. In a more particular example, communications systems 826 can include hardware, firmware, and / or software that can be used to establish a wired connection using any suitable port and / or communication standard (e.g.. VGA. DVI video. USB, RS-232, etc.). Wi-Fi connection, a Bluetooth connection, a cellular connection, an Ethernet connection, and so on.

[0062] In some embodiments, memory 828 can include any suitable storage device or devices that can be used to store instructions, values, data, or the like, that can be used, for example, by processor 822 to control the one or more inputs 824, and / or receive data from the one or more inputs 824; to generate images from data; present content (e.g., data, images, a user interface) using a display; communicate with one or more computing devices 750; and so on. Memory 828 can include any suitable volatile memory, non-volatile memory7, storage, or any suitable combination thereof. For example, memory7828 can include RAM, ROM, EPROM. EEPROM, other ty pes of volatile memory7, other types of non-volatile memory7, one or more types of semi-volatile memory, one or more flash drives, one or more hard disks, one or more solid state drives, one or more optical drives, and so on. In some embodiments, memory7828 can have encoded thereon, or otherwise stored therein, a program for controlling operation of data source 702. In such embodiments, processor 822 can execute at least a portion of the program to generate images, transmit information and / or content (e.g., data, images, a user interface) to one or more computing devices 750, receive information and / or content from one or more computing devices 750, receive instructions from one or more devices (e.g., a personal computer, a laptop computer, a tablet computer, a smartphone, etc.), and so on.

[0063] In some embodiments, any suitable computer-readable media can be used for storing instructions for performing the functions and / or processes described herein. For example, in some embodiments, computer-readable media can be transitory7or non-transitory. For example, non-transitory computer-readable media can include media such as magnetic media (e.g., hard disks, floppy disks), optical media (e.g., compact discs, digital video discs.Blu-ray discs), semiconductor media (e.g., RAM, flash memory', EPROM, EEPROM), any suitable media that is not fleeting or devoid of any semblance of permanence during transmission, and / or any suitable tangible media. As another example, transitory computer- readable media can include signals on networks, in wires, conductors, optical fibers, circuits, or any suitable media that is fleeting and devoid of any semblance of permanence during transmission, and / or any suitable intangible media.

[0064] As used herein in the context of computer implementation, unless otherwise specified or limited, the terms “component,” “system,” “module,” “framework,” and the like are intended to encompass part or all of computer-related systems that include hardware, software, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a processor device, a process being executed (or executable) by a processor device, an object, an executable, a thread of execution, a computer program, or a computer. By way of illustration, both an application running on a computer and the computer can be a component. One or more components (or system, module, and so on) may reside within a process or thread of execution, may be localized on one computer, may be distributed between two or more computers or other processor devices, or may be included within another component (or system, module, and so on).

[0065] In some implementations, devices or sy stems disclosed herein can be utilized or installed using methods embodying aspects of the disclosure. Correspondingly, description herein of particular features, capabilities, or intended purposes of a device or system is generally intended to inherently include disclosure of a method of using such features for the intended purposes, a method of implementing such capabilities, and a method of installing disclosed (or otherwise known) components to support these purposes or capabilities. Similarly, unless otherwise indicated or limited, discussion herein of any method of manufacturing or using a particular device or system, including installing the device or system, is intended to inherently include disclosure, as embodiments of the disclosure, of the utilized features and implemented capabilities of such device or system.Example 1

[0066] In an example study, patient-specific collimator holders were designed and manufactured in accordance with embodiments described in the present disclosure and then used to deliver minibeam radiation therapy treatment to patients.

[0067] In the example study, the 180 kVp output from an Xstrahl 300 orthovoltage unit(Xstrahl Inc.. Suwanee, GA, USA) was used for all measurements and patient treatments. X-ray tube specifications were a half value layer of 0.5 mm Cu, focal spot size of 8 mm, and a target angle of 30°. The unit was calibrated for absolute dosimetry according to the AAPM Task Group 61 in-air protocol using an ionization chamber calibrated by an accredited dosimetry laboratory. The nominal dose rate for standard, non-MBRT treatments was approximately 200 cGy / min at 1 cm depth in water with a tube current of 10 mA.

[0068] Circular cones having a focus-to-source distance of 30 cm with diameters of 3, 4, 5, 8, and 10 cm were commissioned for MBRT. The homogeneous x-ray output from the circular cones was spatially separated into minibeams using custom-made tungsten collimators (Midwest Tungsten Services, Willowbrook, IL, USA). Two square collimators were fabricated, one with outer dimensions of 7 x 7 cm2for use with the 3, 4, and 5 cm cones, and the other with outer dimensions of 12 x 12 cm2for use with the 8 and 10 cm cones. The tungsten collimators were 2.5 mm thick and have 0.5 mm wide slits that are spaced 1.1 mm on center. These dimensions were chosen to be similar to previous in silico and preclinical studies. Slit lengths were 5 cm and 10 cm for the 7 x 7 cm2and 12 x 12 cm2collimators, respectively. The collimator slits are non-divergent to avoid the complexity that would arise from having to align the collimator with the divergent x-ray beam for patient treatments. Because the tungsten collimator is only 2.5 mm thick, the effects of divergence are small and were deemed clinically acceptable.

[0069] Minibeam dosimetry was performed using Gafchromic EBT4 film (Ashland, Bridgewater. NJ. USA) calibrated with the 180 kVp output from the Xstrahl 300 unit. Film analysis was performed using FilmQA Pro software (Ashland, Bridgewater, NJ, USA) following AAPM Task Group 235 recommendations. Minibeam peak and valley doses were measured in a stack of 30 x 30 x 20 cm3Plastic Water DT (CIRS, Norfolk, VA, USA) which is suitable for energies as low as 50 keV. For each circular cone, film measurements were made perpendicular to the axis of the beam from the surface to a depth of 7 cm in 1 cm increments. Measurements were made with the tungsten collimator directly on the plastic water (no offset), as well as with the tungsten collimator offset by 0.5 and 1 cm above the plastic water. The cone was then placed flush on the surface of the tungsten collimator prior to delivering radiation. The offset measurements were made to better approximate clinical scenarios where, due to anatomical considerations, the tungsten collimator cannot be placed directly on the target. Films were irradiated with 900 monitor units (MUs) which resulted in a peak dose range of approximately 700 cGy at the surface to 100 cGy at 7 cm depth. All measurements were repeated 3 times by 3 separate physicists.

[0070] More than 24 hours after exposure, an Epson 12000 flatbed scanner was used to scan all films at a resolution of 1200 dpi. Peak and valley doses were obtained at each depth by averaging along a 1 cm long, 200 micron wide line profile positioned on each of the 10 central peaks and adjacent 10 valley regions on each film. Since measurements were repeated 3 times, this resulted in a total of 30 central peak and valley dose measurements at each depth. A single representative peak and valley dose for each depth was then calculated from the average of these 30 measurements. By dividing the measured doses by the number of MU delivered, dose rates in cGy / MU were obtained at each depth. These dose rates were then converted to percentage depth dose (PDD) curves to be used for subsequent dose calculations. PDDs were normalized to the peak dose at 1 cm which was the chosen prescription depth for patient treatments.

[0071] Despite the larger size of minibeams compared to microbeams, patient motion during lengthy treatment times is still a concern due to the low dose rate of the orthovoltage unit. To mitigate the effects of motion, 3D printed collimator holders, which conform to the unique anatomy of each individual patient, were made using the techniques described in the present disclosure. The tungsten collimators slide into these holders which are then affixed directly to the patient. This ensures that if motion occurs, the patient and collimator move together, maintaining the integrity of the spatially separated peak and valley doses.

[0072] To create the patient-specific collimator holder, a CT scan of the patient was used. The patient was positioned comfortably with support devices and vacuum cushions as appropriate. If possible, the patient was positioned so the w eight of the tungsten collimator helps hold the collimator holder in place rather than pulling it tangentially to either side. For example, a patient with a target on the left neck may be placed in the right lateral decubitus position rather than supine. A 3D rendering of the body surface was obtained from the CT scan and the physician contoured the target. Using the Varian contouring workspace (Varian Medical Systems, Palo Alto, CA, USA), a square structure having dimensions of either 7 x 7 cm2or 12 x 12 cm2corresponding to the size of the tungsten collimator appropriate for the target was created. This structure was positioned over the target and oriented as close as possible to the surface while making sure the tungsten collimator will not impinge upon the patient. Once an appropriate orientation was found, the DICOM RT structure set was saved and exported into Materialise Mimics Medical software (version 26.0, Materialise N.V., Leuven, Belgium) for creation of the 3D printed collimator holder.

[0073] The objects contained within the Mimics file included the patient body, target, and collimator structures which were subsequently moved to Materialise 3-Matic Medical software (version 17.0, Materialise N.V., Leuven, Belgium). A generic collimator holder template was aligned with the tungsten collimator structure in the orientation where the tungsten slides into the holder. Once the tungsten collimator structure and collimator holder were properly located, the generic collimator template was Boolean subtracted from the body surface contour to create the patient-specific collimator holder that conformed to the patient. The collimator holder was evaluated for any areas which may prevent proper positioning, as well as ensuring adequate points of contact for a conformal fit and stability in the desired location. Any sharp, skin-contacting edges were removed and the collimator holder was labeled with a unique identifier, fiducials to check dimensional accuracy, and the anatomic location and orientation. Digital mockups of the design were reviewed and approved by a physicist and physician, then exported as STL files for 3D printing with vat photopolymerization technology on a Form 3B printer in Biomed Amber resin (Formlabs, Somerville, MA). After printing, the part was post-processed according to manufacturer instructions, and holes were tapped and fitted with 4-48 spring plungers (McMaster Carr, Elmhurst, IL) to help secure the tungsten collimator within the collimator holder. Generating a 3D printed collimator holder can be completed in 24 hours, the majority of which was used for printing and post-processing. The general process for creating the collimator holder is illustrated in the example illustrated in FIGS. 4A-4C.

[0074] For treatment, the patient was placed in the same position as the simulation CT scan. The 3D printed holder was placed on the patient without the tungsten collimator in place so the physician can clinically confirm the location of the target. Once it was determined the collimator holder fits appropriately and was comfortable, it was further secured using an elastic strap that attached to the collimator holder. A small piece of Gafchromic film was placed directly on the target for in vivo dosimetry, and the tungsten collimator was then inserted into the collimator holder. Based on target size, an appropriate cone diameter was chosen by the physician and the orthovoltage unit was positioned with the end of the cone in direct contact and flush with the surface of the tungsten collimator. Using the commissioning measurements, MUs were calculated to deliver the prescribed peak dose at 1 cm depth and treatment was delivered.

[0075] The patient was monitored with audio and video during the entire treatment. Due to the small size and spacing of the irradiated regions along with the inherent uncertaintyin day-to-day patient positioning, the peak and valley regions cannot be aligned exactly for multiple treatments. Therefore, for a two-fraction regimen the process was repeated the second day with the collimator rotated by 90° within the collimator holder. This “crossfire” arrangement resulted in only small overlapping peak regions where the cumulative dose doubles without compromising normal tissue tolerance.Example 2

[0076] In another example study, patient-specific collimator holders were designed and manufactured in accordance with embodiments described in the present disclosure and then used to deliver minibeam radiation therapy treatment to a different cohort of patients.

[0077] Patients with symptomatic cutaneous and subcutaneous malignancies were considered for MBRT when standard treatments including other forms of radiotherapy were deemed unlikely to safely achieve disease control.

[0078] MBRT treatment planning included a pretreatment CT scan and contouring of the gross tumor volume (GTV). These contours were then utilized to design a patient-specific three-dimensional printed collimator holder which conforms to the anatomy of the patient. The median time between the planning scan and treatment was 6 days (range 0 days to 18 days), which limited the risk that tumor growth would compromise the fit of the collimator holder. At treatment, a tungsten MBRT collimator with 0.5 mm wide slits spaced 1.1 mm on center was placed within the holder and attached directly to the patient such that the tungsten collimator was directly over the GTV.

[0079] After appropriate set up, MBRT was delivered using either 100 or 180 kVp x- rays from an Xstrahl 300 clinical orthovoltage unit. Radiation was administered using circular cones ranging from 3-10 cm in diameter. The prescription dose was defined to be the peak dose at either the skin surface or a depth of 1 cm. Corresponding valley doses were determined by both the prescribed peak dose and the size of the treatment cone, as the valley dose scales with both quantities. In vivo dosimetry was performed on each patient using radiochromic film placed directly on the target and patients were monitored by video and audio at all times. The median irradiation time was 7.4 minutes with a range of 4.7 to 12 minutes based on the prescription dose.

[0080] A retrospective review of patient records was performed to assess treatment response and toxicity. Symptomatic response was evaluated through patient records and documented interactions between patient and care teams, while radiographic response was assessed using available serial imaging, including both independent review of images andofficial radiology reports. Radiographic response was reported for the treated lesion as well as systemic disease burden. Treatment response was classified into four categories: complete response (CR) defined as absence of any detectable disease, partial response (PR) defined as reduction in tumor size and / or decrease in FDG activity as measured by standardized uptake values (SUVs), stable disease (SD) defined as no significant change in tumor size or metabolic activity, and progressive disease (PD) defined as continued tumor growth or increased metabolic activity. For patients who underwent surgical resection of the treated area, pathologic response was also documented.

[0081] In the study, 21 patients with a total of 26 lesions underwent MBRT. The median time from initial diagnosis of the target lesion to MBRT was 8.8 months. Fourteen patients had metastatic disease, while 4 patients had local recurrence without metastatic disease. Three patients had neither metastatic nor recurrent disease. Seven patients each had melanoma or squamous cell carcinoma. At the time of presentation for MBRT, 71.4% had disrupted skin while the remainder had intact skin with subcutaneous or mucosal disease (oral cavity lesions).

[0082] Targeted lesions were in the head and neck (n=15), trunk / extremities (n=5), axilla (n= 3), and breast (n=3). The median lesion size was 4.9 cm (range, 2.4-15 cm). Eleven patients had prior local treatment including seven that had radiotherapy with a median time from first course to MBRT of 15 months. The prior radiation doses ranged from 20 Gy in 5 fractions to 70 Gy in 35 fractions. Ninety percent of all patients had been previously treated with multiple lines of systemic therapy including chemotherapy, immunotherapy, and targeted therapy.

[0083] Twelve patients (57%) had MBRT as the primary' local treatment. Nine patients received MBRT in combination with external beam radiation therapy. Outcomes and toxi cities were analyzed separately for these two groups given the heterogeneity of radiation dosing. Follow-up data was available for 95% of patients (n=20) with a median follow-up of 10 months. Eighty -five percent of patients had 3-month follow up and 50% of patients had 6- month follow up. Median progression free survival (PFS) was 5 months. Overall, local control of the target lesion, defined as complete response, partial response, or stable disease, was achieved in 83% of patients who received MBRT, 67% of patients who received MBRT + EBRT, and 75% of all patients.Example 3

[0084] In another example study, patient-specific collimator holders were designed and manufactured in accordance with embodiments described in the present disclosure and then used to deliver minibeam radiation therapy treatment to a patient with a cancerous tumor affecting their right eye.

[0085] MBRT treatment planning included a pretreatment CT scan and delineation of the gross tumor volume (GTV). A patient-specific three-dimensional (3D) printed plastic collimator holder which conformed to the patient’s face was fabricated. This device held a tungsten collimator in place directly above the GTV. For MBRT treatment delivery, the plastic collimator holder with the collimator in place was secured to the patient. A total peak dose of 60 Gy to the skin surface was prescribed to be delivered in 2 daily fractions to the right inferior orbit and maxillary sinus treatment. The 180 kV output from an Xstrahl 300 (Xstrahl Inc) orthovoltage unit was used for treatment. An 8 cm diameter circular cone defined the overall field size and was positioned such that the end of the cone was flush with the surface of the tungsten collimator. Between the first and second fractions, the tungsten collimator was rotated by 90 degrees. Therefore, the peak dose prescription corresponds to the overlapping regions of the slits between the two fractions. The valley dose was 4 Gy per fraction and the irradiation time was 11 minutes. Six weeks later, the process was repeated to treat the right upper medial orbit with a prescription peak dose of 50 Gy to the skin surface in 2 daily fractions. Due to the smaller size and shallow depth of the target, a 5 cm diameter circular cone and 100 kV x-ray energy was used. The valley dose per fraction was 2.7 Gy and the irradiation time was 8 minutes.

[0086] Within days following the first fraction of MBRT, the patient reported improvements in their ability to open their eye. Over the next several weeks, the patient reported significant and rapid shrinkage of the mass surrounding their right eye with improved vision. PET / CT imaging before and after MBRT to the right inferior orbit and face showed a complete metabolic response of metastatic melanoma at 13 weeks post-MBRT consistent with clinical response. PET / CT imaging before and 7 weeks after MBRT to the right upper medial orbit also showed a complete metabolic response.

[0087] The present disclosure has described one or more preferred embodiments, and it should be appreciated that many equivalents, alternatives, variations, and modifications, aside from those expressly stated, are possible and within the scope of the invention.

Claims

CLAIMS1. A method for creating a patient-specific collimator holder for a radiation therapy treatment, the method comprising: receiving, using a computing device, three-dimensional (3D) imaging data; generating, using the computing device, a 3D volume of a patient from the 3D imaging data; determining, using the computing device, a region-of-interest (ROI) for receiving radiation therapy within the 3D volume of the patient; generating, using the computing device, a 3D model of a collimator holder from the 3D volume of the patient and the ROI, the 3D model having an inner surface that conforms to an exterior surface of the 3D volume; and outputting, by the computing device, the 3D model of the collimator holder.

2. The method of claim 1, wherein outputting the 3D model of the collimator holder comprises causing, using the computing device, a 3D printer to construct a collimator holder from the 3D model of the collimator holder.

3. The method of claim 2, wherein the 3D printer constructs the 3D model from a biocompatible filament that is extrudable through an extruder of the 3D printer.

4. The method of claim 3, wherein the biocompatible filament comprises one of a biocompatible resin or nylon.

5. The method of claim 1. wherein generating the 3D model of the collimator holder comprises accessing, with the computing device, a collimator holder template model and subtracting at least one of the 3D volume of the patient or the ROI from the collimator holder template model.

6. The method of claim 5. wherein subtracting the at least one of the 3D volume of the patient or the ROI from the collimator holder template model comprises a Boolean subtraction.

7. The method of claim 5. wherein generating the 3D model of the collimator holder further comprises adding a supporting element volume to the collimator holder template model, wherein the supporting element volume spans an anatomical structure of the patient in the 3D volume of the patient to provide additional structural support for the 3D model of the collimator holder.

8. The method of claim 1, wherein the 3D volume of the patient depicts a portion of the patient.

9. The method of claim 8. wherein the portion of the patient depicted by the 3D volume comprises a skin surface of the patient.

10. The method of claim 9, wherein the portion of the patient depicted by the 3D volume comprises a skin surface of the patient in addition to internal anatomy of the patient.

11. A patient-specific collimator holder for use in minibeam radiation therapy, the collimator holder comprising: a body extending from a first surface to a second surface opposite the first surface, wherein the second surface conforms to an exterior surface of a portion of a patient adjacent a region-of-interest (ROI) that is to receive mini beam radiation therapy, the exterior surface of the patient including skin of the patient; an aperture directed through the body that corresponds to the shape and the size of the ROI that is to receive radiation therapy, the aperture aligning with at least a portion of the ROI when the collimator holder is interfaced with the exterior surface of the patient; and a slot formed in the body and sized to receive a collimator.

12. The collimator holder of claim 11, wherein the radiation shield is constructed by additive manufacturing.

13. The collimator holder of claim 12, wherein the collimator holder is constructed using a three-dimensional (3D) printer.

14. The collimator holder of clam 11, wherein the body is composed of one of a biocompatible resin or nylon.

15. The collimator holder of claim 11, further comprising a coupling to secure the body of the collimator holder to the exterior surface of the patient, wherein the coupling includes an adhesive disposed on the second surface of the body.

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