1. Technical Field
The present disclosure relates to manufacturing bolus for use in radiotherapy and more specifically to customized, user-specific bolus for accurately targeting a specific treatment area. The disclosure also addresses creating bolus for different types of therapy, including photon therapy, electron therapy, and proton therapy. The disclosure also describes how a bolus can be incorporated into an immobilization device, and how a custom, 3D-printed bolus can incorporate dosimeter functionality.
2. Introduction
Radiotherapy is a treatment for disease in which an affected part of the body of a patient is exposed to ionizing radiation. For a range of treatment applications, an adequate surface dose is required, particularly in the presence of superficial target volumes. Since megavoltage radiation beams do not deposit maximal dose at the skin surface, in these cases surface dose can be increased by overlaying a tissue equivalent material, called bolus. Bolus is most commonly used in conjunction with electron therapy which is well suited to treatment of superficial lesions with a single beam. A second purpose of bolus is controlling the depth in tissue at which a therapeutic dose of radiation is deposited, and modulating this depth as a function of position across the beam.
Currently, radiation therapists manually create bolus. For example, a radiation therapist can apply wax or thermoplastic sheets to the patient surface. Often, a radiation therapist heats the wax or other material to make it more pliable or malleable. The radiation therapist can apply the bolus material in one or more layers to conform to the patient surface. Often the radiation therapist attempt to manually create a regular geometry or a flat surface at the location of beam incidence. The patient and radiation therapist must then wait while the bolus material cools.
This manual approach is limited in regard to accuracy, practicality and quality of the delivered treatment. First, this process is labor intensive because it involves manual application of bolus material. This occupies the patient, potentially multiple staff members, as well as clinic space, often in an expensive or valuable computed tomography (CT) suite. Second, the bolus should conform well to the patient skin, even in situations where the geometry is complex, such as an outer ear, canthus, lip, or other extremities. The capacity of manually produced bolus to conform to irregular surfaces is limited. Inaccuracy of bolus fabrication can result in air gaps between the bolus and patient surface. Air gaps, in turn, can result in substantial inaccuracies in delivered surface dose, for example, exceeding 10%. In practice, this sometimes prompts filling of air gaps with wet gauze, however the variability in the wetness of the gauze causes inconsistency in delivered dose. Third, bolus is commonly pre-defined in the planning system as a water equivalent, uniform layer on the patient surface. The similarity of the planned and fabricated bolus is limited with regard to both thickness and curvature, particularly in the presence of steep, complex or curved surfaces. This compromises the accuracy of the delivered dose distribution relative to the plan. Fourth, other than controlling the depth of penetration of an electron beam into tissue, manually manufactured bolus does not achieve conformity between the radiation dose and the target volume. Most commonly, the high dose region will encompass the deepest aspect of an irregularly shaped tumor but also a volume of surrounding healthy tissue which would be preferable to avoid exposing to excess radiation.
A system, method and computer-readable storage devices are disclosed which provide a way to plan radiotherapy treatment, such as with a single electron beam or one or more photon beams, using computer models of the patient derived from three-dimensional imaging data, while delivering an adequate dose to the planning target volume (PTV) of the patient while minimizing the dose to surrounding healthy tissues and normal structures of the patient. Bolus can be custom manufactured for patients to achieve this goal, such as with a three-dimensional printer.
The approach described herein can provide several advantages. For example, patients already undergo CT imaging for treatment planning. The example system can design bolus digitally with high accuracy and precision based on this three dimensional data set without the patient's presence. The system can design the bolus so that the upper (proximal) surface of the bolus enhances the dose conformity, dose homogeneity, dose uniformity, quality, or effective area of the radiation delivered plan. Further, the system can manufacture the bolus using additive manufacturing, such as three dimensional printing technology. The printed bolus may be manufactured using polylactic acid (PLA), which is biocompatible. PLA is derived from starches (e.g. corn) and is already used for medical implants in the form of screws, pins, rods, and mesh.
3D printing is a specific form of additive manufacturing. One of the most common methods of 3D printing, and the one explored in this work is Fused Deposition Modeling (FDM). This process has recently has become widely accessible at low cost, such as MakerBot devices. 3D printing involves a fabrication process that uses a CAD model as input to create a 3D physical model by applying many successive layers of the chosen material at a high resolution, such as a resolution of 100 micrometers, although the system can use other resolutions and capabilities.
3D printing provides several advantages over the manual approach to bolus fabrication. Bolus fabrication can be largely automated, and the precision can be substantially improved. Because the fabrication is automated, human error is reduced. Thus, 3D printed bolus can provide improved conformity between bolus and patient surface, reducing the possibility of air cavities which would degrade accuracy of treatment or would provide a dosage above or below what is desired. PLA bolus is durable, unlike traditional wax bolus materials. Increased durability can be particularly important for treatment regimes with the bolus over an extended period of time, such as a regime of 30 daily treatments. A precisely generated bolus can provide a customized, highly conformal dose distribution for each individual patient based on his or her specific needs and situation. 3D printing allows for a clinic or doctor to fabricate optimized bolus designs in-house rather than placing an order to an off-site service which may be expensive or require a lengthy wait. 3D printing can provide a cost reduction, time savings, improved treatment flexibility, and ability to respond to changing clinical demands by modifying the bolus design during the course of the treatment.
Aside from these practical advantages, digital design and 3D printing of bolus can also improve the delivered treatment. Currently, the electron therapy planning process involves the selection of beam energy and electron aperture dimensions to achieve adequate coverage of the Planning Target Volume (PTV). 3D printing allows for customizing the patient surface to optimize the shape of the dose distributions produced at a particular depth and region within the PTV. This concept is illustrated in
A bolus 102 can be constructed for multiple different types of radiation therapy. For example, a bolus 102 can be constructed for use in photon therapy, electron therapy, or proton therapy. The propagation and other characteristics of photons, electrons, and protons are different. Thus, different bolus shapes, sizes, thicknesses, and/or constructions can be used to target a treatment dose of radiation to a same body region using different radiation therapies.
Radiation therapy professionals can use a bolus for megavoltage photon therapy, particularly when a maximal dose is required at the patient's skin. A 3D-printed bolus can be produced, based on measurements of the patient's skin contours and the target treatment region within the body. With accurate measurements of the patient's skin and body contours, the 3D-printed bolus can be shaped to mate accurately to the patient surface, even in the presence of very complex geometries, such as the regions around the face, ears, or surgical cavities. As set forth above, while the patient-facing surface of the bolus is shaped based on the body geometry, the non-patient facing surface of the bolus is shaped so that radiation treatments, when applied from one or more points external to the body through the bolus, are directed to affect only a specific desired treatment target region within the body and/or at the surface of the skin.
However, due to differences in the way photons interact and/or propagate compared to electrons and protons, it is difficult to control high-dose conformity (agreement between shapes of the high dose volume and the target) through the use of bolus. Therefore, the system can produce an accurately fitting bolus of a thickness (or variable thickness, if desired) specified by a doctor or other radiation treatment professional, to achieve the required dose of radiation treatment at the surface. Any accurate photon dose calculation can be used in conjunction with this design process. In one example implementation, the system uses the Anisotropic Analytic Algorithm (AAA, from Varian Medical), but many other suitable algorithms exist and can be used interchangeably. Advantages of the approach include but are not limited to (i) bolus design from CT data, resulting in less human involvement in the bolus creation process, (ii) bolus conformity to complex surfaces (e.g., surgical site post-mastectomy), and (iii) specification of thickness or density of bolus (which in turn controls the surface dose).
Since some of the most challenging and common scenarios for use of bolus involve electron beam therapy, many of the examples provided herein focus primarily on that application. While the design of the distal surface (the surface mating to the skin) is based on CT data indicating the surface and contours of the patient, design of the bolus to target the PTV via the proximal surface is non-trivial. Electrons scatter within any medium in a complex way, and thus simple approaches such as ray-tracing are not adequate. An algorithm for bolus design can achieve specific dosimetric goals. The system can incorporate this algorithm in to a common treatment planning approach. The system can provide an interface allowing production of the optimized bolus using 3D printing. The algorithm can operate in conjunction with an external beam planning system, obviating the need to re-implement a system accurate dose calculation. The system can incorporate the electron Monte Carlo (eMC) algorithm. A block diagram 200 of an iterative approach of the algorithm is outlined in
After calculating an initial dose distribution in absence of bolus 202, the treatment plan, CT set, structures and dose distribution are provided to a system 204 implementing the algorithm. The system 204 calculates an initial approximation of bolus design to achieve conformal coverage of the target volume. The system can provide the bolus design back to the planning system for dose calculation with the bolus design 206. The system can iterate this process in an automated fashion with subsequent cycles also addressing more subtle aspects of improvement of the dose distribution, such as hot-spots, cool spots and optimization of conformity at the edges of the target volume. For example, if the dose calculation with bolus 206 is not acceptable 208, then the system 204 can iterate on the bolus design again. Empirical evidence shows that 2-3 iterations are usually sufficient to achieve high plan quality. If, however, the bolus design is acceptable 208, then the bolus can be exported, such as via an STL file format, to a bolus fabrication device 210, such as a 3D printer. The bolus fabrication device 210 can manufacture the bolus with minimal user intervention. Following manufacture, a doctor or radiation therapist can place the bolus on the patient to confirm that the positioning and fit are proper. If desired, the doctor or radiation therapist can perform an additional CT scan with the bolus in place to collect a final dose calculation with the actual manufactured bolus. The example dose calculation 214 can operate according to the electron Monte Carlo (eMC) algorithm, but can be replaced with any suitably accurate electron dose calculation algorithm. Similarly, for different types of radiation therapy, different algorithms can be applied, such as an algorithm for proton or photon therapy.
The bolus optimization and design system of
Since patients typically contain tissue inhomogeneities, zreal is converted to an effective distance zeff using the coefficient of equivalent thickness (CET) method. The effective shift of bolus thickness (SBT) of a certain point p on the grid is given by:
where CET(z) is the density at point z relative to that of water. Note that because the initial plan is calculated with no bolus and the requirement is complete coverage of the PTV by the 90% dose surface, all SBTp values will be positive in the first iteration. In subsequent iterations, SBTp values are used to adjust the design of the bolus resulting from the previous iteration (
Regional modulation: While the calculation of SBT values largely improves conformity of the 90% isodose surface, it does not address secondary effects, such as regional hot or cold spots or the effect of irregular bolus surface. Separate regional modulation operators are developed to address: i) hot spots in the PTV, ii) undercoverage, iii) irregular bolus surface, iv) coverage at the PTV margin, and v) extension of the bolus beyond the PTV. These operators are applied sequentially; however, we reiterate that the dose calculation is performed only by the eMC algorithm in the planning system. Three of the operators (i-iii) involve regional smoothing. In these cases, the SBT matrix is segmented into regions of interest containing points p where modulation is required, neighboring points q that are used to smooth p, and points outside of the region of interest (
where rpq is the distance between p and q, and SF(mm) is the smoothing factor, controlling the width of smoothing region and smooth level (i.e., 5, 10, and 20 mm for low, medium, and high).
Smoothing for hot spot: The first modulation operator aims to alleviate the hot spots that exist within the distribution after the previous iteration of eMC dose calculation (
Smoothing for dose coverage: Although the calculation of SBT values aims to provide full coverage by the 90% isodose surface, accurate eMC calculation following bolus design may reveal undercoverage in certain regions of the PTV. In these regions, SBT values will be negative (i.e., to decrease bolus thickness). However, testing of the effect of SBT adjustment alone reveals that the bolus thinning must be extended somewhat beyond the region defined by the projection of the under dosed area. Accordingly, negative SBT values in the region of interest are retained, while surrounding values are smoothed (see
Smoothing for potential irregular surface: Following the previous operations, discontinuities may be present at the boundaries of regions of interest. Surface irregularities are identified by using a gradient threshold criterion equal to two times of the mean value of gradient magnitude, and smoothed using RM(Mode 2) (
Adjustment at PTV margin: Relative to more central regions, the edge of the PTV receives less scattered radiation dose simply due to collimation by the electron applicator. To remedy underdosing in this region, a region of interest is defined as a 10 mm wide border inside of the projection of the PTV onto the SBT matrix (
where values are adjusted along radial lines from the central axis: m exists on the inner boundary of the region of interest, p exists within the region of interest, rpm is the distance between p and m,
(i.e., the distance over which KerfMA(x) increases from 0.01 to 1 (
sigma=√{square root over (Energy×Applicatior))}
is employed.
Shift outside PTV: The area corresponding to all ray lines between the edge of the PTV and a distance 1.0 cm beyond the electron aperture are subject to this operator. In this region, bolus thicknesses are simply extruded:
SBTp=SBTn
where n is the intersection of PTV contour and line from p to the projection of central axis (
Certain radiation treatments are directed to sensitive parts of the body, such as radiation therapy for breast cancer. Breast tissue is deformable and can change position and shape more than body parts with bones to support and give structure. Thus, a bolus for use with radiation therapy for breast cancer treatments may be difficult to position. Further, certain portions of the affected region of the body, such as skin on the inframammary fold, may become irritated or have other issues stemming from radiation treatment. To address these and other issues, the system can analyze CT scan data of the breast, and 3D print an immobilization support to stabilize the breast. Additionally, a custom 3D-printed bolus, as described above, can be incorporated into the immobilization support.
The system can, when designing such a 3D-printed immobilization support 600 and integrated bolus 602, reduce of build-up effect outside of the bolus area. The system can control various aspects of the immobilization mesh 604, such as the mesh density or size of cells in the mesh, the thickness of the ‘lines’ of 3D-printed material in the mesh, or effective electron density of the 3D-printed material (sometimes called ‘infill’ in 3D printing terminology). In one variation, the immobilization support 600 can be 3D printed to include brackets or grommets or some other attachment for connecting the strap 606.
In a progressively changing radiation treatment, the system can receive CT scan data (or other body imaging data) of the patient, and design a series of immobilization meshes 604 and boluses 602 for different stages of the treatment plan. For example, the treatment plan may include a high dose of electron radiation for weeks 1 and 2, while the electron radiation dose is lowered for weeks 3 and 4. The system can design, and 3D-print on-demand (such as the night before an appointment at which a new bolus is required), a first combination immobilization mesh 604 and bolus 602 for weeks 1 and 2, and a second combination immobilization mesh 604 and bolus 602 for weeks 3 and 4. Each combination is based on the same patient CT scan data, but incorporates a bolus 602 of a different shape, size, type, and/or in a different position on the immobilization mesh 604. Additionally, the system can incorporate feedback from the treatment progress and revise yet-unprinted ones in the series to be tailored for the changing radiation therapy needs and the body's changing reactions to the radiation therapy.
When applying radiation therapy, doctors (or others) often wish to know whether the radiation is being administered properly, and how much radiation is being administered, among other data points. A 3D-printed bolus can include several mechanisms for collecting this data. For example, a 3D-printed bolus can be designed so that the 3D printing process creates (or leaves) a specific cavity or cavities in the bolus for receiving radiation dosimeters. A doctor or other user can insert a radiation dosimeter into the cavity in the bolus prior to treatment to gather data during treatment, then can remove the radiation dosimeter after treatment. The shape of the cavity can be tailored for a specific kind of dosimeter, so only the correct type of dosimeter(s) will fit. The cavity can be virtually any shape, and can optionally include latches, brackets, or other restraining mechanism to position the dosimeter and retain it in place. Because the 3D design and printing process allows full control of the 3D design of the bolus, dosimeters can be embedded within the bolus to enable in vivo dosimetry. Example dosimeters include ionization chambers, diodes, metal-oxide-semiconductor field-effect transistors (MOSFETs), radiographic film, radiochromic film, diamond detectors, optically stimulated luminescence dosimeters (OSLDs), or arrays thereof. Because the bolus is in direct contact with the skin, the dosimeters can also be placed proximal to the skin surface (or very close to the skin surface within or on the bolus) to allow real-time readout of the radiation dose received by the skin during treatment.
In one embodiment, the material making up the bolus can itself be a sort of dosimeter. Certain materials are scintillators, or materials which exhibit scintillation, the property of luminescence when excited by ionizing radiation, such as PET or PEN plastics that are 3D-printable. Scintillators can be organic crystals or liquids, inorganic crystals, specialized glass, as well as plastic scintillators. Plastic scintillators typically include a scintillator (or fluor) suspended in a polymer base. As the 3D printer creates the bolus, all the material from which the bolus is created can include one or more scintillator materials. Then, as the bolus is used in the radiation therapy, the scintillators react and fluoresce. The bolus can include different kinds of scintillators triggered at different radiation levels. Thus, the type, amount, or position of scintillator reacting can provide an indication of the quantity and location of the administered radiation. The 3D printer can also incorporate different scintillators in different regions of the bolus. The 3D printer can incorporate scintillators in the bolus in patterns that form words or symbols when a suitable radiation dose is applied to the bolus. For example, the majority of the bolus material is a non-scintillator, and during 3D printing, certain regions of the bolus are constructed with scintillator materials in patterns that fluoresce when exposed to a specific amount of radiation. Then, when the bolus is used for treatment, the patterns of scintillator materials embedded in the bolus fluoresce. In one example, a pattern of scintillator material in the shape of a smiley face, a checkmark, or the word “YES” can fluoresce when the radiation is at a desired level. Conversely, patterns of scintillator materials embedded in the bolus can also indicate when the dose is too low or too high with different patterns, such as a letter “X” or a frowny face. With respect to the immobilization mesh 604, the 3D printer can also include scintillators in the immobilization mesh 604 to provide a visual indication of whether the dose of radiation is insufficient or is too high.
While the primary embodiment discussed herein is a bolus that is in direct contact with the skin of a patient, similar 3D-printing approaches and algorithms can be adapted for other, related uses that custom adapt a radiation dose for a patient but that are not in direct contact with the skin of the patient. For example, instead of an algorithm for shaping a bolus to be applied to a patient's skin in order to deliver a desired radiation dose, a similar design process and similar algorithm can be applied to design a custom proton compensator to be positioned upstream in a proton radiation beam. Such a proton compensator would not be in direct contact with the patient's skin, but would be upstream. When in position for the proton radiation beam, the custom, patient-specific proton compensator modulates the depth of the high dose deposited as a function of position across the beam so that the desired amount of proton radiation is delivered and that the therapeutic dose distribution conforms to the curvature of the deep aspect of the tumor volume. Radiation treatment can include a combination of a proton compensator upstream and a bolus in contact with the patient's skin.
The system performs a second dose calculation for the treatment goal for the target radiation treatment area based on the model for the target bolus (708). When the second dose calculation satisfies conditions associated with the treatment goal, the system can output the model for the target bolus to a fabrication device to produce a replica of the target bolus for use with the target radiation treatment area of the user. If the second dose calculation does not satisfy the conditions associated with the treatment goal, the system can perform an analysis of the model for the target bolus for at least one of a hot spot, a cool spot, dose coverage, surface irregularity, a margin of a planning target volume, or conformity at edges of the planning target volume. Based on the analysis, the system can revise the model to yield a revised model, and output the revised model to the fabrication device to produce the replica of the target bolus for use with the target radiation treatment area of the user. The replica can be made up of polylactic acid, or some other material suitable for use with a 3D printer. The system can iterate the analysis and revising the model until the revised model satisfies the conditions associated with the treatment goal. The fabrication device can be a 3D printer. The model can be an STL file. The system can present or render the model in a user interface prior to fabrication via the 3D printer.
After the bolus is 3D printed, the system can verify that it satisfies the conditions associated with the treatment goal based on a computed tomography scan of the bolus while placed on the target radiation treatment area of the user. The system can similarly gather radiation data via dosimeters embedded in the bolus, inserted into the bolus, or via scintillators that are part of the bolus material.
The patient-facing side of the bolus is shaped to conform to a surface of the target radiation treatment area. The beam-incident side of the replica can be shaped to a regular geometric surface or to some other shape or contour such that radiation passed through the bolus is delivered in a desired dosage to a desired portion of the skin or body of the user when placed on the target radiation treatment area of the user and a radiation beam is applied to the target radiation treatment area of the user through the bolus. The bolus can be reusable for multiple radiation treatment sessions.
Various embodiments of the disclosure are described in detail herein. While specific implementations are described, it should be understood that this is done for illustration purposes only. Other components and configurations may be used without parting from the spirit and scope of the disclosure.
With reference to
The system bus 810 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. A basic input/output (BIOS) stored in ROM 840 or the like, may provide the basic routine that helps to transfer information between elements within the computing device 800, such as during start-up. The computing device 800 further includes storage devices 860 or computer-readable storage media such as a hard disk drive, a magnetic disk drive, an optical disk drive, tape drive, solid-state drive, RANI drive, removable storage devices, a redundant array of inexpensive disks (RAID), hybrid storage device, or the like. The storage device 860 can include software modules 862, 864, 866 for controlling the processor 820. The system 800 can include other hardware or software modules. The storage device 860 is connected to the system bus 810 by a drive interface. The drives and the associated computer-readable storage devices provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for the computing device 800. In one aspect, a hardware module that performs a particular function includes the software component stored in a tangible computer-readable storage device in connection with the necessary hardware components, such as the processor 820, bus 810, display 870, and so forth, to carry out a particular function. In another aspect, the system can use a processor and computer-readable storage device to store instructions which, when executed by the processor, cause the processor to perform operations, a method or other specific actions. The basic components and appropriate variations can be modified depending on the type of device, such as whether the device 800 is a small, handheld computing device, a desktop computer, or a computer server. When the processor 820 executes instructions to perform “operations”, the processor 820 can perform the operations directly and/or facilitate, direct, or cooperate with another device or component to perform the operations.
Although the exemplary embodiment(s) described herein employs the hard disk 860, other types of computer-readable storage devices which can store data that are accessible by a computer, such as magnetic cassettes, flash memory cards, digital versatile disks (DVDs), cartridges, random access memories (RAMs) 850, read only memory (ROM) 840, a cable containing a bit stream and the like, may also be used in the exemplary operating environment. Tangible computer-readable storage media, computer-readable storage devices, or computer-readable memory devices, expressly exclude media such as transitory waves, energy, carrier signals, electromagnetic waves, and signals per se.
To enable user interaction with the computing device 800, an input device 890 represents any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and so forth. An output device 870 can also be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multimodal systems enable a user to provide multiple types of input to communicate with the computing device 800. The communications interface 880 generally governs and manages the user input and system output. There is no restriction on operating on any particular hardware arrangement and therefore the basic hardware depicted may easily be substituted for improved hardware or firmware arrangements as they are developed.
For clarity of explanation, the illustrative system embodiment is presented as including individual functional blocks including functional blocks labeled as a “processor” or processor 820. The functions these blocks represent may be provided through the use of either shared or dedicated hardware, including, but not limited to, hardware capable of executing software and hardware, such as a processor 820, that is purpose-built to operate as an equivalent to software executing on a general purpose processor. For example the functions of one or more processors presented in
The logical operations of the various embodiments are implemented as: (1) a sequence of computer implemented steps, operations, or procedures running on a programmable circuit within a general use computer, (2) a sequence of computer implemented steps, operations, or procedures running on a specific-use programmable circuit; and/or (3) interconnected machine modules or program engines within the programmable circuits. The system 800 shown in
One or more parts of the example computing device 800, up to and including the entire computing device 800, can be virtualized. For example, a virtual processor can be a software object that executes according to a particular instruction set, even when a physical processor of the same type as the virtual processor is unavailable. A virtualization layer or a virtual “host” can enable virtualized components of one or more different computing devices or device types by translating virtualized operations to actual operations. Ultimately however, virtualized hardware of every type is implemented or executed by some underlying physical hardware. Thus, a virtualization compute layer can operate on top of a physical compute layer. The virtualization compute layer can include one or more of a virtual machine, an overlay network, a hypervisor, virtual switching, and any other virtualization application.
The processor 820 can include all types of processors disclosed herein, including a virtual processor. However, when referring to a virtual processor, the processor 820 includes the software components associated with executing the virtual processor in a virtualization layer and underlying hardware necessary to execute the virtualization layer. The system 800 can include a physical or virtual processor 820 that receive instructions stored in a computer-readable storage device, which cause the processor 820 to perform certain operations. When referring to a virtual processor 820, the system also includes the underlying physical hardware executing the virtual processor 820.
Embodiments within the scope of the present disclosure may also include tangible and/or non-transitory computer-readable storage devices for carrying or having computer-executable instructions or data structures stored thereon. Such tangible computer-readable storage devices can be any available device that can be accessed by a general purpose or special purpose computer, including the functional design of any special purpose processor as described above. By way of example, and not limitation, such tangible computer-readable devices can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other device which can be used to carry or store desired program code in the form of computer-executable instructions, data structures, or processor chip design. When information or instructions are provided via a network or another communications connection (either hardwired, wireless, or combination thereof) to a computer, the computer properly views the connection as a computer-readable medium. Thus, any such connection is properly termed a computer-readable medium. Combinations of the above should also be included within the scope of the computer-readable storage devices.
Computer-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing device to perform a certain function or group of functions. Computer-executable instructions also include program modules that are executed by computers in stand-alone or network environments. Generally, program modules include routines, programs, components, data structures, objects, and the functions inherent in the design of special-purpose processors, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of the program code means for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps.
Other embodiments of the disclosure may be practiced in network computing environments with many types of computer system configurations, including personal computers, hand-held devices, multi-processor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. Embodiments may also be practiced in distributed computing environments where tasks are performed by local and remote processing devices that are linked (either by hardwired links, wireless links, or by a combination thereof) through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
The various embodiments described above are provided by way of illustration only and should not be construed to limit the scope of the disclosure. For example, the principles herein can be applied to any clinical case involving electron beam therapy. The 3D printing process can also apply to x-ray photon beam therapy over multiple sites where the tumor volume is superficial, although the design process for the bolus may be modified somewhat for photons. The bolus design algorithm can be changed, for example, to support photon or proton transport instead of electron transport. The eMC algorithm in 202, 206, and 214 can be replaced by a megavoltage photon dose calculation algorithm. Various modifications and changes may be made to the principles described herein without following the example embodiments and applications illustrated and described herein, and without departing from the spirit and scope of the disclosure. Claim language reciting “at least one of” a set indicates that one member of the set or multiple members of the set satisfy the claim.
This application is a continuation of International Application No. PCT/CA2014/051128 (published as WO 2015/077881), filed on Nov. 26, 2014, which claims priority to U.S. Provisional Patent Application No. 61/909,789, filed on Nov. 27, 2013; the contents of both applications are herein incorporated by reference in their entirety.
Number | Date | Country | |
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61909789 | Nov 2013 | US |
Number | Date | Country | |
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Parent | PCT/CA2014/051128 | Nov 2014 | US |
Child | 15157029 | US |