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WO2018081420A1 - Procédés d'assurance et de vérification de la qualité de radiothérapie - Google Patents

Procédés d'assurance et de vérification de la qualité de radiothérapie Download PDF

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Publication number
WO2018081420A1
WO2018081420A1 PCT/US2017/058524 US2017058524W WO2018081420A1 WO 2018081420 A1 WO2018081420 A1 WO 2018081420A1 US 2017058524 W US2017058524 W US 2017058524W WO 2018081420 A1 WO2018081420 A1 WO 2018081420A1
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WIPO (PCT)
Prior art keywords
phantom
disk
region
module
disks
Prior art date
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Ceased
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PCT/US2017/058524
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English (en)
Inventor
Peter Demetri OLCOTT
Rostem BASSALOW
Brent Harper
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RefleXion Medical Inc
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RefleXion Medical Inc
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Publication of WO2018081420A1 publication Critical patent/WO2018081420A1/fr
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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/037—Emission tomography
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/58—Testing, adjusting or calibrating thereof
    • A61B6/582—Calibration
    • A61B6/583—Calibration using calibration phantoms
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/1048—Monitoring, verifying, controlling systems and methods
    • A61N5/1075—Monitoring, verifying, controlling systems and methods for testing, calibrating, or quality assurance of the radiation treatment apparatus
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N5/00—Radiation therapy
    • A61N5/10—X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy
    • A61N5/1048—Monitoring, verifying, controlling systems and methods
    • A61N5/1071—Monitoring, verifying, controlling systems and methods for verifying the dose delivered by the treatment plan

Definitions

  • Radiation therapy involves the emission of high-energy X-rays to targeted tumor regions within a patient's body. Images of the location and geometry of tumor regions are acquired before the treatment session, and the based on this data, a treatment plan is formulated to deliver the desired dose of radiation to the targeted tumor regions.
  • a treatment plan may include instructions to the radiation therapy system as to the firing angle of the radiation source (e.g., linac), as well as the state of any beam-shaping components (e.g., jaws and/or collimators) at particular firing angles in order to deliver the desired radiation dose.
  • BGRT biologically-guided radiation therapy
  • EGRT emission-guided radiation therapy
  • signals from the targeted tumor regions may be incorporated with the treatment plan in order to compensate for any changes in tumor location or geometry that may have occurred between the treatment planning session and the treatment session.
  • the patient may be injected with the PET tracer that is preferentially taken up by tumor regions prior to the treatment session.
  • Lines-of-response (LORs) that indicate the occurrence of a positron annihilation event within a tumor region are detected by PET detectors of the radiation therapy system and used to update or modify the treatment plan, if needed, to compensate for any tumor movement.
  • a desired dose of radiation has been delivered according to a treatment plan (that may or may not be modified by detected LORs)
  • Such phantoms may aid in the development of treatment plans and/or calibration of the various components of a radiation system (e.g., gantry rotation and radiation source timing, collimator control, etc.).
  • a phantom for use in a biologically-guided radiation therapy system, such as an emission-guided radiation therapy system.
  • a phantom may comprise an oblong or cylindrical housing having a longitudinal lumen therethrough, a plurality of blocks or disks that are sized and shaped to be arranged or stacked within the housing, and a plurality of radiographic sheets of film disposed between at least two of the plurality of disks within the housing.
  • the phantom may also comprise an end cap that may be disposed over one end of the housing, and may be used to retain and/or compress the disks and film sheets together within the housing (i.e., to reduce or eliminate the air gap between the disks and film sheets).
  • the plurality of disks may comprise a material that emits positrons (e.g., PET-avid).
  • One or more of the plurality of disks may comprise a first region that has a first level of PET activity and a second region that has a second level of PET activity that is higher than the first level.
  • the second region may have any desired cross-sectional shape, for example, a circle, semi-circle, arc, etc.
  • the first region may be a background region that represents a low level of PET tracer uptake and the second region may be a target region that represents a higher level of PET tracer uptake that simulates the uptake of a tumor region.
  • the disks may comprise a radioactive epoxy (e.g., Ge-68), and may optionally include one or more radiopaque materials distributed within the epoxy and/or throughout the disk.
  • the background and target region(s )of a disk may comprise radioactive epoxy, where the radioactive epoxy in the background region may have a lower PET tracer concentration (or lower levels of PET activity per unit mass per unit volume in ⁇ /g) than the radioactive epoxy in the target region(s).
  • the ratio of PET tracer concentration or activity of the target region(s) to the PET tracer concentration or activity of the background region may be from about 2: 1 to about 16: 1.
  • the PET activity concentration in the background and the target regions may vary in the ranges of 0.1 ⁇ /mL to 20 ⁇ /mL.
  • the standard uptake value (SUV) between the target region and the background region may be from about 1 to 100, e.g., about 2 to 16.
  • a radiographic sheet e.g.,
  • GAFCHROMICTM film may be disposed between some of the plurality of disks and not others.
  • a radiographic sheet may be disposed between two disks that each have target regions.
  • a phantom may comprise an array of radiation sensors located between consecutive disks, such as two disks that each has target regions.
  • phantom assemblies that comprise one or more phantoms that may be movable with respect to each other.
  • a phantom assembly may comprise a base having a first longitudinal lumen and a second longitudinal lumen, a first cylindrical phantom module slidably disposed within the first longitudinal lumen, and a second cylindrical phantom module slidably disposed within the second longitudinal lumen.
  • the cylindrical phantom modules may be configured to rotationally and/or laterally slide within the lumens.
  • the first and second longitudinal lumens may be adjacent to each other.
  • a base may have a third longitudinal lumen located between the first and second longitudinal lumens, and the third longitudinal lumen may have a smaller diameter than the first and second longitudinal lumens.
  • the cylindrical phantom modules may each comprise a cylindrical housing having a longitudinal lumen therethrough, a plurality of disks that are sized and shaped to be stacked within the housing, and a plurality of radiographic sheets of film disposed between at least two of the plurality of disks within the housing.
  • the phantom module may also comprise an end cap that may be disposed over one end of the housing, and may be used to retain and/or compress the disks and film sheets together within the housing.
  • a third cylindrical phantom module comprising a PET-avid material and one or more radiographic sheets may be slidably disposed within the third longitudinal lumen.
  • the base may be filled with a radioactive or nonradioactive material, including but not limited to, radioactive materials (e.g., radioactive epoxy such as Ge-68 epoxy, PET tracers such as FDG), or non-radioactive materials (e.g., water, plastic, acrylic).
  • radioactive materials e.g., radioactive epoxy such as Ge-68 epoxy, PET tracers such as FDG
  • non-radioactive materials e.g., water, plastic, acrylic.
  • a phantom disk may comprise an enclosed shell having an internal volume, a first region of the volume comprising a first material, and a second region of the volume comprising a second material that is more radioactive than the first material.
  • the second material may emit more positrons than the first material.
  • the first material may have a first standard uptake value and the second material may have a second standard uptake value that is greater than the first standard uptake value.
  • the second standard uptake value may be about four times greater than the first standard uptake value.
  • the first material may comprise Ge-68 epoxy that has a first standard uptake value and the second material may comprise Ge-68 epoxy that has a second standard uptake value that is about four times greater than the first standard uptake value.
  • the second region may have a smaller volume than the first region.
  • the second region may have a circular cross-section, and/or the second region may have an arc-shaped cross-section.
  • the disk may have a thickness and the second region may extend across the entire thickness of the disk.
  • the internal volume of the shell may be filled with a radioactive liquid.
  • the internal volume of the shell may be filled with a radioactive solid or radioactive gel.
  • a phantom module may comprise a housing comprising a longitudinal lumen therethrough, a plurality of phantom disks stacked within the longitudinal lumen, a plurality of dosimetry sensors disposed between the plurality of phantom disks, and a cap that may enclose the longitudinal lumen such that the phantom disks and the dosimetry sensors are retained and compressed within the lumen.
  • At least one of the plurality of phantom disks may comprise a background region and a target region, where the target region may be more radioactive than the background region.
  • the target region of the at least one of the plurality of phantom disks may have a higher rate of positron emissions than the background region.
  • the standard uptake value of the target region may be greater than the standard uptake value of the background region.
  • the standard uptake value of the target region may be four times greater than the standard uptake value of the background region.
  • the target region may have a circular cross-section and/or may have an arc-shaped cross-section.
  • at least one of the plurality of phantom disks may comprise a radiopaque material.
  • the dosimetry sensors of a phantom module may comprise radiographic film.
  • FIG. 1 depicts one variation of a radiation therapy system.
  • FIG. 2 is a schematic depiction of one variation of a phantom module.
  • FIG. 3 A is a schematic depiction of a front view of one variation of a disk-shaped phantom.
  • FIG. 3B is a perspective side view of the disk-shaped phantom of FIG. 3 A.
  • FIG. 4A is a schematic depiction of a front view of one variation of a disk-shaped phantom.
  • FIG. 4B is a perspective side view of the disk-shaped phantom of FIG. 4A.
  • FIG. 4C is a cross-sectional view (taken along line A-A) of one variation of a disk-shaped phantom similar to the phantom depicted in FIG. 4A.
  • FIG. 4D is a cross-sectional view (taken along line A-A) of another variation of a disk-shaped phantom similar to the phantom depicted in FIG. 4A.
  • FIG. 5A is a schematic depiction of a front view of one variation of a disk-shaped phantom.
  • FIG. 5B is a perspective side view of the disk-shaped phantom of FIG. 5 A.
  • FIG. 5C is a cross-sectional view (taken along line A-A) of one variation of a disk-shaped phantom similar to the phantom depicted in FIG. 5A.
  • FIG. 5D is a cross-sectional view (taken along line A-A) of another variation of a disk-shaped phantom similar to the phantom depicted in FIG. 5 A.
  • FIG. 6A is a schematic depiction of a front view of one variation of a disk-shaped phantom.
  • FIG. 6B is a perspective side view of the disk-shaped phantom of FIG. 6A.
  • FIG. 6C is a cross-sectional view (taken along line A-A) of the disk-shaped phantom of FIG. 6A.
  • FIG. 7A is a schematic depiction of a front view of one variation of a disk-shaped phantom without a target region.
  • FIG. 7B is a perspective side view of the disk-shaped phantom of FIG. 6 A.
  • FIG. 8A is a schematic representation of one variation of a phantom assembly comprising a plurality of phantom modules.
  • FIG. 8B is a schematic representation of one variation of a phantom assembly comprising a plurality of phantom modules.
  • FIG. 8C is a schematic representation of one variation of a phantom assembly.
  • FIG. 8D is a schematic representation of one variation of a phantom module.
  • FIG. 9A is a schematic depiction of a perspective view of one variation of a phantom module.
  • FIG. 9B is a transverse cross-sectional view of the phantom module of FIG. 9A.
  • FIG. 9C is a perspective view of a housing of the phantom module of FIG. 9A.
  • FIG. 1 OA is a schematic depiction of a perspective view of another variation of a phantom module.
  • FIG. 10B is a transverse cross-sectional view of the phantom module of FIG. 10A.
  • FIG. 11 is a schematic depiction of a perspective view of one variation of a phantom module.
  • FIG. 12A is a schematic representation of one variation of a phantom assembly comprising a plurality of phantom modules.
  • FIG. 12B is an exploded view of one variation of a phantom module with a plurality of orthogonal films and/or detector arrays.
  • FIG. 12C is a schematic representation of one variation of a phantom module with a plurality of orthogonal films and/or detector arrays.
  • phantoms for the characterization, qualification and calibration of radiation therapy system including biologically-guided radiation therapy systems (e.g., emission-guided radiation therapy system).
  • biologically-guided radiation therapy system may comprise a rotatable gantry, one or more PET detectors mounted on the gantry, a radiation source mounted on the gantry, and a beam-shaping assembly disposed in the radiation beam path of the radiation source.
  • the beam-shaping assembly may comprise one or more sets of jaws and/or collimators.
  • FIG. 1 One variation of a radiation therapy system is depicted in FIG. 1.
  • a radiation therapy system 100 may comprise an arcuate or circular gantry 102 having a bore 104, a first array of PET detectors 106a located along a first length of the gantry, a second array of PET detectors 106b located along a second length of the gantry, and a linear acceleration (linac) 108 located between the first and second PET detector arrays.
  • the first array of PET detectors 106a and the second array of PET detectors 106b may be located across (e.g., opposite) each other.
  • the system 100 may also comprise a multi-leaf collimator 110 mounted on the gantry 102, disposed in the beam path 112 of the linac 108.
  • the multi-leaf collimator 110 may be, in some variations, a binary multi-leaf collimator.
  • the open and closed states of the individual leaves of the multi-leaf collimator may be independently controlled by a controller that is in communication with all of the components of the system 100.
  • the gantry may be a fast rotating gantry with a speed from about 20 RPM to about 70 RPM, e.g., about 60 RPM.
  • the system 100 may be configured to detect positron emission paths or lines of response (LORs) emitted from a patient (e.g., tumor regions that have taken up an injected PET tracer) during a treatment session and to apply radiation beams to target regions in the patient in response to the detected LORs.
  • LORs positron emission paths or lines of response
  • the multi-leaf collimator disposed in the beam path of the linac may shape the beam emitted from the linac, applying a pattern of beamlets to targeted patient regions.
  • radiation beamlets may be fired along detected LORs.
  • the system 100 may be configured to continuously detect LORs from the patient to deliver a real-time motion compensated treatment to multiple target regions.
  • the data from the LORs detected during a treatment session may be analyzed and used to update treatment plans that may have been formulated based on diagnostic images acquired in advance of the treatment session (e.g., days, weeks, or even months before the treatment session).
  • some radiation therapy systems may comprise an imaging system, such as a CT system, that may be used to acquire patient images just before, during and/or after the treatment session.
  • the system may undergo quality assurance testing, registration and/or calibration and/or verification procedures prior to a treatment session or during periodic checks.
  • Such procedures may use one or more structures or phantoms that simulate PET-avid tissue, such as PET-avid target tissue and PET-avid, non-target tissue (e.g., "background" tissue).
  • a phantom may comprise a target region that simulates a first PET-activity level and a background region that simulates a second PET- activity level that is less than the first PET-activity level.
  • the target region may emit LORs at a higher rate than the background region, simulating the preferential uptake of PET tracers, including but not limited to FDG, for example, by tumor tissue than non-tumor tissue.
  • Phantoms may have a variety of shapes, as may be desired, and may be cylinder-shaped, disk-shaped, oblong-shaped, etc.
  • Some phantoms may comprise one or more radiographic films or sheets and/or radiation detectors located at the target region in order to acquire images or data that indicate the amount of radiation dose delivered to the target region. Radiographic films or sheets or radiation detectors may also be provided to non-target regions of a phantom to determine whether these regions are exposed to unwanted levels of radiation. The size and shape of a target region, as well as the number of target regions, in a phantom may be varied as desired.
  • a phantom module may comprise a plurality of phantom disks that are arranged or stacked within a housing.
  • At least a subset of the disks may comprise target regions that when arranged with surrounding disks that have target regions that align together, form an overall target region within the phantom module.
  • the overall target region may simulate a tumor region within a patient's lung, for example.
  • the phantom disks may be sized and shaped to be arranged within the module housing in any desirable fashion.
  • the phantom module housing may have a generally cylindrical shape having a longitudinal axis (e.g., lying on an x-axis) and a transverse axis (e.g., lying on a y-axis, perpendicular to the longitudinal axis).
  • the disks may be shaped such that the plurality of disks is arranged along the longitudinal axis.
  • the phantom disks may be shaped as a half-cylinder (i.e., a cylinder that has been cut longitudinally down its central axis), and a phantom module may comprise two half-cylinder shaped phantoms that are arranged along the transverse axis, where a first half-cylinder phantom is a top portion of a cylinder and the second half-cylinder phantom is a bottom portion of the cylinder.
  • the phantom module may also comprise disks that are shaped as sections of a cylinder that has been cut longitudinally at various locations along the transverse axis.
  • a phantom or phantom module may be coupled to an actuator that may be configured to move the phantom laterally or rotationally to simulate patient movement during treatment (e.g., due to breathing, fidgeting, shifting body positions, etc.).
  • a plurality of phantoms may be arranged relative to each other to simulate the position of anatomical structures.
  • a phantom assembly that simulates a patient's torso may comprise a first phantom module, a second phantom module, and a base that retains the first and second phantom modules adjacent to each other to simulate the relative positioning of the lungs.
  • the first and second phantom modules may have a mass density that is less than that of water, for example about 20% to about 40% of the mass density value of water.
  • the phantom assembly may comprise a third phantom module coupled to the base that simulates the position of the spine relative to the lungs.
  • These phantoms may comprise one or more radiographic sheets of film or radiation detectors.
  • the first and second phantom modules may comprise at least one target region with a PET activity that simulates the PET-activity level of a tumor region.
  • the third phantom module may not have any target regions or regions of elevated PET-activity levels, but may comprise one or more radiographic sheets of film or radiation detectors to detect whether unwanted radiation is delivered.
  • the third phantom may also have mass density value that is different from the first and second phantom modules.
  • the mass density value of the third phantom may be similar to that of bone, to simulate the bony structure of a spine (or any skeletal structure). This may help to develop treatment plans and/or control algorithms that are capable of heterogeneous dose calculation to help reduce the exposure of radiation-sensitive regions, such as the spine, to unwanted levels of radiation.
  • the phantoms described herein may be used to characterize, calibrate, and/or verify the expected or desired function of the linac, multi-leaf collimator, PET detectors, and rotatable gantry, as well as to characterize treatment plans formulated based on diagnostic images and to verify performance of dose delivery and dose calculation algorithms.
  • one method of characterizing a treatment plan may comprise placing a phantom within a patient treatment region of a radiation therapy system, where the phantom has target regions with elevated PET- activity levels and background regions with relatively lower PET-activity levels. LORs emitted from the phantom may be detected by the one or more PET detectors.
  • Location data of the target region based on the detected LORs may be used in conjunction with a treatment plan to rotate the gantry to position the linac at a selected firing angle, open and close selected leaves of the multi-leaf collimator, and emit radiation beams to the target regions.
  • the treatment plan may have been formulated based on the particular size, shape, and location of the target region(s) of the phantom.
  • the phantom may comprise a plurality of radiographic films and/or radiation detectors located throughout the phantom that acquire radiation dose measurements during the "treatment session". At the conclusion of the session, data from the radiographic films may be used to compute the amount of dose applied to the phantom during the "treatment session" and/or may be used to generate a dose map.
  • a 3D dose distribution may be obtained in the "lung" cylinders by interpolating the 2D dose measured on films due to the parallel stacking geometry of the films and having one film at each end of the cylinder.
  • 3D dose volume histograms can be then calculated for the lung and tumor volumes.
  • the dose map and the DVH may be compared to the treatment plan to identify any dose deviations.
  • the operation of the linac, gantry, and the multi-leaf collimator may also be validated and/or characterized based on the radiation dose data and/or map acquired by the radiographic films and/or radiation detectors. Other methods of characterizing the radiation therapy system and/or individual components of the system may include any of the phantoms described herein.
  • Phantom module 200 may comprise a cylindrical housing 201 having a longitudinal lumen 202, a plurality of PET-avid disks 204 located within the lumen, and one or more radiographic films 206 located between two or more of the disks, and an end cap 203 enclosing an open end of the housing lumen 202.
  • the phantom module 200 may additionally or alternatively comprise radiation detectors (e.g., two-dimensional silicon, diamond, calorimetric or plastic scintillation detector arrays, thin-film detectors or sensors, etc.) located between two or more of the disks.
  • the disks 204 may be cylindrical with a flattened edge 205.
  • the disks may have a flattened peripheral surface and an arcuate peripheral surface.
  • An internal wall 212 of the longitudinal lumen 202 may comprise a curved portion and a flattened portion, such as a longitudinally- extending flattened surface 210, and aligning the flattened edge 205 of each of the disks with the flattened surface 210 of the longitudinal lumen 202 prevents rotational motion of the disks 204 within the housing 201.
  • the module may be oriented such that the flattened surface 210 may be the bottom (e.g., below the curved portion) or alternatively, the module may be oriented such that the flattened surface 210 may be the top (e.g., above the curved portion).
  • the disks may comprise a PET-avid material that is distributed throughout the volume of the disk.
  • the disks may be filled with Ge-68 epoxy.
  • Some disks may have a substantially homogenous PET-activity level throughout the entire volume of the disk (e.g., disk 204a), while other disks (e.g., disk 204b) may have one or more regions of elevated PET-activity levels.
  • a region of elevated PET-activity levels e.g., region 218) may simulate a tumor region that has taken up more PET tracer than other surrounding regions.
  • regions of elevated PET-activity levels are referred to as target regions, while the remaining region of the disk (e.g., non-target region) is referred to as the background region.
  • the homogeneity of both the background and target regions should be within about 5% across the entire background or target region.
  • the absolute concentration of the radioactive material within the background or target region of a disk should not deviate more than about 10% across the region.
  • the disks may be filled with a non-radioactive or non-PET-avid material.
  • the boundary or junction between the perimeter of a target region and a background region may comprise a small region that is not PET-avid (a "dead area"), while in other variations, there is little or no such dead area between the perimeter of the target region and the background region. Dead areas located around target regions may unrealistically improve the contrast around the target region that is detected by the therapy system and/or introduced unwanted artifacts.
  • the outer surface of a disk may be made of a plastic (i.e., non-PET-avid material and/or a material that is dosimetrically similar to water), the thickness of the outer surface of a disk may also act as dead areas that introduce artifacts and artificially-high contrast lines.
  • the thickness of a first surface 214 and a second surface 216 of a disk 204, along with the internal boundary between a target region 218 and the background region 220 may be between about 0.05 mm to about 0.5 mm, e.g., less than about 0.25 mm. Accordingly, the dead area may be from about 0.1 mm to about 1 mm, and may preferably be less than about 0.5 mm, or less than 0.2 mm. There may be any number of disks within a housing 201, for example, 2, 3, 4, 5, 6, 7, 9, 10, 12, 15, 19, 20, 22, etc.
  • the thickness of the disks may be from about 7 mm to about 100 mm, e.g., about 10 mm, about 20 mm, about 50 mm, about 75 mm, etc.
  • the disks may comprise a radiopaque material distributed throughout the epoxy.
  • the background region of a disk may comprise a radiopaque material that provides about 50 HU of contrast.
  • the total radioactivity of the phantom module 200, including all of the disks, may be less than about 1 mCi.
  • the three- dimensional target region may be made up of the target regions of multiple disks. That is, the target region of multiple disks may be segments of the overall three-dimensional target region. Stacking together multiple disks and aligning their target regions may then create the overall three-dimensional target.
  • a phantom module kit may comprise disks with a variety of different target geometries and/or segments that may be stacked together to build a three-dimensional target region of a desired size or shape.
  • the disks may be re-ordered or shuffled to create different sizes and/or shapes of target regions, and in some variations, may be ordered in a stack such that the overall target region approximates a treatment or tumor region of a patient.
  • radiographic films or radiation detector arrays may be disposed between the disks to detect the dosage applied to different portions of a target region.
  • a phantom module may comprise a first set of disks that have no target regions and a second set of disks that have one or more target regions, where stacking the second set of disks together may create a three-dimensional target region.
  • the disks and films/arrays may be compressed together by attaching the end cap to the opening of the cylindrical housing.
  • the end cap may be attached to the cylindrical housing by screw-fit, and where tightening down the end cap may compress the disks together and reduce the gaps between the disks.
  • the end cap may comprise a rigid material and/or may comprise a bias member (e.g., a spring) that applies a longitudinal compressive force on the disks and films/arrays.
  • the surface flatness over the face of a disk is may be configured to help facilitate continuous and smooth contact with radiographic film. Continuous contact with radiographic film may help improve the accuracy and precision of the dose data collected by the film.
  • the flatness of the face(s) of a disk that contact the face(s) of adjacent disks and/or radiographic film or radiation detector array may be such that the height differential across the surface of the face is no greater than approximately 20 microns to about 50 microns.
  • the module or block may be injection molded, mechanically or laser machined, and/or sanded to the desired shape and/or tolerance.
  • FIGS. 3A and 3B depict one variation of a disk 300 that may be used in a phantom module, such as the phantom module depicted in FIG. 2.
  • the disk 300 may comprise nonradioactive shell or container that encloses a radioactive material or non-radioactive material.
  • the shell or container may comprise a plastic and/or any material that is dosimetrically similar to water, and the radioactive material enclosed in the shell may comprise a radioactive (e.g., PET-avid) epoxy, such as Ge-68 epoxy.
  • Other radioactive fluids e.g., liquids, such as PET tracers, including FDG
  • the disk may comprise a background region 302 having a first PET-activity level and a target region 304 having a second PET-activity level value that is greater than the first PET-activity level.
  • radiopaque materials may be mixed in the radioactive epoxy.
  • both the background region 302 and the target region 304 may comprise Ge-68 epoxy, but the target region may include additional amounts of PET-avid material.
  • the background region may simulate non-specific uptake of a PET tracer in a patient and the target region may simulate increased uptake of a PET tracer in a tumor.
  • the cross-sectional shape of the target region 304 is depicted in the front-view of the disk in FIG. 3A.
  • the target region 304 has a circular cross-section, but it should be understood that a target region may have any desired cross-sectional shape, such as rectangular shape (e.g., square), trapezoidal, oval or elliptical shape, an arc-shape (e.g., hemi-arc, hemi- spherical, hemi-cylindrical), etc.
  • the diameter of the disk 300 may be from about 7 cm to about 20 cm, e.g., from about 6 cm to about 10 cm, about 12 cm, and the diameter of the target region may be from about 0.25 cm to about 5 cm, e.g., from about 0.5 cm to about 3.5 cm.
  • SUV of the background region may be from about 1 to about 8, e.g., about 2, and the SUV of the target region may be from about 16 to about 32.
  • the ratio of PET tracer concentration between the target region and the background region may be from about 2: 1 to about 16: 1.
  • FIGS. 4-7 depict several variations of disks, some of which have different sized and different shaped target regions, or no target regions at all.
  • Two disks may have targets that have the same shape as viewed from a first surface (e.g., front surface), but have different shapes when viewed from a second surface that is perpendicular to the first surface (e.g., side surface).
  • the cross-sectional shape of the target region may be circular, while the side-view of the target region may have semi-circular shape in one disk and the side-view of the target region may have a rectangular shape.
  • FIGS. 4A-4B One variation of a disk 400 having a circular target region 402 as viewed from a front face is depicted in FIGS. 4A-4B.
  • the sectional view of the target region taken along line A-A of the disk may have a rectangular shape 404 that extends through the entire thickness of the disk 400', while in other variations, the sectional view of the target region taken along line A-A of the disk may have a semi-circular shape 406 that does not extend through the entire thickness of the disk 400" .
  • Disk 400' having the rectangular shape 404 target region and the disk 400" having a semi -circular shape 406 target region may be stacked adjacent to each other in a cylindrical housing along with another disk (not shown) having a semi-circular shape target region like disk 400" (but flipped) to form an overall ovoid-shaped or rounded elongated target region (e.g., the two disks having semi -circular shaped targets stacked on either side of the disk having the rectangular shaped target).
  • the diameter of the disk 400, 400', 400" may be about 98 mm, the diameter of the target region 402 may be about 15 mm, and the radius of the semi-circular target region 406 may be about 7.5 mm, and the thickness of the disk 400, 400', 400" may be about 9.9 mm.
  • the activity concentration of the background region 408 may be from about 0.2 ⁇ /cc to about 0.75 ⁇ /cc (about 7.5kBq/cc - about 27.8 kBq/cc).
  • the activity concentration of the target region 402 may from about 2-4 times greater than that of the background region 108, e.g., from about 0.8 ⁇ /cc to about 3 ⁇ /cc (about 30kBq/cc - about 111.2 kBq/cc).
  • the disk 400, 400', 400" may comprise a radioactive epoxy (e.g., Ge-68), and/or may also include radiopaque materials (e.g., iodide).
  • the radioactive epoxy in the background region may comprise low density particles (e.g., air bubbles or materials such as plastics, glass, cork, wood, saw dust, etc.) to reduce the SUV and/or radiopacity of the background region relative to the target region.
  • a target region may comprise an added X-ray contrast of approximately 50 HU +/-10 (Hounsfield Units), which may allow for CT imaging (e.g., with a 140 keV diagnostic CT system).
  • a phantom module or assembly may be positioned using KVCT, MVCT or orthogonal pair radiographic imaging, three or more high density or metal fiducial beads or pellets may be embedded into the target or background material. For example, two beads may be placed along the IEC X axis, and one at the top edge of the disk along the IEC Z axis.
  • FIGS. 5A-5B Another variation of a disk 500 having a circular target region 502 as viewed from a front face is depicted in FIGS. 5A-5B.
  • the sectional view of the target region taken along line A-A of the disk may have a rounded shape 504 similar to a segment of a sphere that does not extend through the entire thickness of the disk 500', while in other variations, the sectional view of the target region taken along line A-A of the disk may have a truncated circular shape 506 that extends through the entire thickness of the disk 500" .
  • Disk 500' having the rounded shape 504 target region and the disk 500" having a truncated circular shape 506 target region may be stacked adjacent to each other in a cylindrical housing along with another disk (not shown) having a rounded shape target region like disk 500' (but flipped) to form an overall spherically shaped target region (e.g., the two disks having rounded shape targets stacked on either side of the disk having the truncated circular shaped target).
  • the diameter of the disk 500, 500', 500" may be about 98 mm
  • the diameter of the target region 502 may be about 25.86 mm
  • the radius of curvature of the rounded shape target region 504 may be about 15 mm
  • the thickness of the disk 500, 500', 500" may be about 14.8 mm or about 14.9 mm.
  • the rounded shape 504 target region may extend about 7.4 mm into the thickness of the disk 500' .
  • the curved portion of the truncated circular shape 506 target region may have a radius of curvature of about 30 mm.
  • the activity concentration of the background region 508 may be from about 0.2 uCi/cc to about 0.75 uCi/cc (about 7.5kBq/cc - about 27.8 kBq/cc).
  • the activity concentration of the target region 502 may from about 2-4 times greater than that of the background region 508, e.g., from about 0.8 uCi/cc to about 3 uCi/cc (about 30kBq/cc - about 111.2 kBq/cc).
  • the disk 500, 500', 500" may comprise a radioactive epoxy (e.g., Ge-68), and/or may also include radiopaque materials (e.g., iodide).
  • the radioactive epoxy in the background region may comprise low density particles (e.g., air bubbles or materials such as plastics, glass, cork, wood, saw dust, etc.) to reduce the SUV and/or radiopacity of the background region relative to the target region.
  • a target region may comprise an added X-ray contrast of approximately 50 HU +/-10 (Hounsfield Units), which may allow for CT imaging (e.g., with a 140 keV diagnostic CT system).
  • a phantom module or assembly may be positioned using KVCT, MVCT or orthogonal pair radiographic imaging
  • three or more high density or metal fiducial beads or pellets may be embedded into the target or background material. For example, two beads may be placed along the IEC X axis, and one at the top edge of the disk along the IEC Z axis.
  • FIGS. 6A-6B Another variation of a disk 600 having a circular target region 602 as viewed from a front face is depicted in FIGS. 6A-6B.
  • the sectional view of the target region taken along line A-A of the disk may have a semi-circular shape 604 similar to a segment of a sphere that does not extend through the entire thickness of the disk 600.
  • Disk 600 having the semi-circular shape 604 target region may be stacked adjacent to another disk (not shown) having a similar semicircular shape target region like disk 600 (but flipped) in a cylindrical housing along with to form an overall spherically shaped target region.
  • the diameter of the disk 600 may be about 98 mm, the diameter of the target region 604 may be about 50 mm, the radius of the semi-circular shape target region 604 may be about 25 mm, and the thickness of the disk 600 may be about 29.9 mm.
  • the activity concentration of the background region 608 may be from about 0.2 uCi/cc to about 0.75 uCi/cc (about 7.5kBq/cc - about 27.8 kBq/cc).
  • the activity concentration of the target region may from about 2-4 times greater than that of the background region 608, e.g., from about 0.8 uCi/cc to about 3 uCi/cc (about 30kBq/cc - about 111.2 kBq/cc).
  • the disk 600 may comprise a radioactive epoxy (e.g., Ge-68), and/or may also include radiopaque materials (e.g., iodide).
  • the radioactive epoxy in the background region may comprise low density particles (e.g., air bubbles or materials such as plastics, glass, cork, wood, saw dust, etc.) to reduce the SUV and/or radiopacity of the background region relative to the target region.
  • a target region may comprise an added X-ray contrast of approximately 50 HU +/-10 (Hounsfield Units), which may allow for CT imaging (e.g., with a 140 keV diagnostic CT system).
  • a phantom module or assembly may be positioned using KVCT, MVCT or orthogonal pair radiographic imaging, three or more high density or metal fiducial beads or pellets may be embedded into the target or background material. For example, two beads may be placed along the IEC X axis, and one at the top edge of the disk along the IEC Z axis.
  • Some disks may not have a target region (i.e., a region of elevated PET-activity level) at all.
  • a disk 700 that comprises a homogenous distribution of a radioactive material (e.g., Ge-68 epoxy) is depicted in FIGS. 7A-7B.
  • the diameter of the disk 700 may be about 98 mm, and the thickness of the disk 700 may be about from about 15 mm to about 70 mm, e.g., about 19.9 mm, about 49.9 mm.
  • the activity concentration of the radioactive epoxy may be from about 0.2 uCi/cc to about 0.75 uCi/cc (about 7.5kBq/cc - about 27.8 kBq/cc).
  • the disk 700 may comprise radiopaque materials (e.g., iodide).
  • the radioactive epoxy may comprise low density particles (e.g., air bubbles or materials such as plastics, glass, cork, wood, saw dust, etc.) to reduce the PET-activity level and/or radiopacity of the disk 700.
  • low density particles e.g., air bubbles or materials such as plastics, glass, cork, wood, saw dust, etc.
  • three or more high density or metal fiducial beads or pellets may be embedded into the target or background material. For example, two beads may be placed along the IEC X axis, and one at the top edge of the disk along the IEC Z axis.
  • the disks depicted in FIGS. 4-7 are described above as comprising a radioactive epoxy, in some variations, the disks may comprise a non-radioactive epoxy.
  • both the background region and the target region may comprise non-radioactive epoxy, and the target region may further comprise an X-ray contrast agent that provides an X-ray contrast with the background region of approximately 50 HU +/-, which may allow for CT imaging (e.g., with a 140 keV diagnostic CT system).
  • Such disks may not radioactive (e.g., not PET-avid), and may be used to characterize, calibrate, and/or verify a CT imaging system that may be included with a radiation therapy system.
  • a plurality of phantom modules may be assembled together to simulate a patient's torso.
  • two phantom modules may be arranged adjacent to each other to simulate a patient's lungs and a third phantom module having a diameter that is smaller than the first two phantom modules may be positioned between them to simulate a patient's spine.
  • the first two phantom modules may be movable in such a way as to simulate lung movements during a treatment session, while the third phantom module may be stationary.
  • the third phantom module may also be movable to simulate patient movement or body shifting during a treatment session.
  • the phantom assembly 800 may comprise a base 802 having a first longitudinal lumen 804a and a second longitudinal lumen 804b, a first cylindrical phantom module 806 slidably disposed within the first longitudinal lumen 804a, and a second cylindrical phantom module 808 slidably disposed within the second longitudinal lumen 804b.
  • the base may comprise a radioactive material (e.g., radioactive epoxy, liquids or gels, or non-radioactive epoxy, liquid or gels).
  • each phantom module may comprise a plurality of stacked disks and a plurality of radiographic sheets of film disposed between at least two of the stacked disks.
  • Each of the disks may comprise a background region with a first PET-activity level and a target region with a second PET-activity level that is higher than the first PET- activity level.
  • a phantom module may comprise any number of disks that have any number, size, and shape of target regions. In the variation depicted in FIG.
  • the first phantom module 806 may comprise a circular (e.g., spherical, elliptical, etc.) target region 810 and the second phantom module 808 may comprise an arc-shaped (e.g., hemi-arc, hemi- spherical, hemi- cylindrical) target region 812.
  • a circular target region 810 e.g., spherical, elliptical, etc.
  • the second phantom module 808 may comprise an arc-shaped (e.g., hemi-arc, hemi- spherical, hemi- cylindrical) target region 812.
  • Each of the phantom modules 806 and 808 may have other target regions with shapes and sizes that are not visible in the cross-section depicted in FIG. 8A.
  • the phantom assembly 800 may also comprise a third phantom module 830 configured to be slidably disposed within a third longitudinal lumen 804c of the base 8
  • the third phantom module 830 may comprise one or more radiographic films or radiation detectors at various locations within the volume of the module.
  • the third phantom module 830 may contain a PET-avid material distributed throughout its internal volume (e.g., Ge-68 epoxy as described above), while in other variations, the third phantom module 830 may contain a non-radioactive material distributed throughout its internal volume (e.g., epoxy or acrylic).
  • the third phantom module 830 may or may not comprise a target region therein with elevated PET-activity level, and may or may not comprise a radiopaque substance, as desired.
  • the third phantom module may have a size and shape similar to that of a patient's spine, and may be positioned with respect to the first and second phantom modules similarly to the relative position of the spine and a patient's lungs.
  • the third phantom module may comprise a target region, and one or more radiographic films or radiation detector arrays may be disposed in proximity to the target region to determine whether a desired dose has been applied to the target region.
  • the third phantom module may not comprise any target regions, but may include a number of radiographic films or radiation detector arrays distributed throughout to measure the level of radiation deposited within the module by the system while depositing dose in either or both of the first and second phantom modules. This may provide information as to whether the spine is subjected to undesired levels of radiation during a treatment session.
  • a phantom assembly may comprise one or more actuators or motors 820, 822 coupled to one or more of the phantom modules, where the actuators or motors are configured to move the phantom modules in such a way as to simulate patient and/or tumor motion.
  • the base of a phantom assembly may be coupled to an actuator or motor 824 that is configured to move the base (and therefore, the phantom modules within the base).
  • the actuator or motor 824 may move the base longitudinally, laterally, and/or may rotate and/or pivot the base.
  • An actuator or motor 820, 822 coupled to a phantom module may be configured to longitudinally translate the module within the lumen of the base.
  • two-axis actuators e.g., that provide linear and rotational movements
  • three-axis actuators e.g., that provide movement in three dimensions, along the x-, y-, and z- axes
  • phantom assemblies or modules may comprise one or more cavities that may be filled with a radioactive or positron-emitting fluid.
  • Radioactive or positron-emitting fluids may include a Ge-68 solution, a PET tracer (e.g., FDG) solution, and the like.
  • the one or more cavities may be adjacent to phantom regions with higher levels of radioactivity and/or PET-activity, to simulate background levels of radioactivity and/or PET- activity (e.g., due to non-specific uptake of radioactive and/or PET tracers) that may be adjacent to tumor regions with elevated levels of radioactivity and/or PET-activity.
  • the level of radioactivity and/or PET-activity of the fluid may be from about 0.2 ⁇ to about 0.75 ⁇ /cc, while the level of radioactivity and/or PET-activity of phantom regions with elevated PET- activity levels (i.e., phantom target regions) may be from about 0.8 ⁇ /cc to about 3 ⁇ /cc.
  • the one or more fluid cavities may surround phantom target regions.
  • Phantom assembly 830 may comprise a base 832 having a first longitudinal lumen 834a and a second longitudinal lumen 834b.
  • the base 832 may comprise a housing 831 that defines a fluid cavity or enclosure volume 833 that surrounds first and second longitudinal lumens 834a, 834b.
  • the first and second longitudinal lumens 834a, 834b are sized and shaped to correspond with first and second phantom modules 836, 838 respectively, such that the phantom modules can be slidably disposed within the lumens.
  • the phantom modules may each comprise a plurality of stacked disks and/or may have one or more target regions 840, 842 that have elevated PET-activity levels, as described previously.
  • the cavity or enclosure volume 833 of the base 832 may be filled with a radioactive or PET-avid fluid, for example, a radioactive epoxy, liquids or gels.
  • the housing 831 may comprise one or more fluid ports 835 through which a radioactive or PET-avid fluid may be injected or removed.
  • the port may comprise a one-way valve to prevent any unwanted fluid flow.
  • a housing may have a first fluid port having a first one-way valve that permits fluid flow into the housing cavity and a second fluid port having a second one-way valve that permits fluid flow out of the housing cavity. Fluids with different levels of PET-activity may be used to simulate or approximate background PET activity for different patients. By changing out the radioactive fluid in the housing cavity or enclosure, a phantom assembly may be customized to simulate the PET tracer uptake for different patients.
  • the ability to introduce fluids with different levels of PET-activity may allow for the evaluation of the radiation therapy system, radiation delivery methods and/or treatment plan under different types of noise environments.
  • the cavity of the housing may be filled with a fluid having increased levels of PET-activity in order to evaluate the performance of the radiation therapy system and treatment plan to simulate a patient who tends to exhibit pervasive nonspecific PET tracer uptake.
  • the phantom assembly 830 and/or phantom modules 836,838 may be coupled to one or more actuators or motors, as described previously with regard to the variation in FIG. 8A.
  • FIG. 8C depicts another variation of a phantom assembly comprising a housing defining a cavity or enclosure volume for radioactive fluid.
  • Phantom assembly 850 may comprise a housing 850 that defines a cavity or enclosure volume 853, and one or more fluid ports 856, 858.
  • Fluid port 856 may be a fluid inlet and fluid port 858 may be a fluid outlet, and may each optionally have a one-way valve.
  • the phantom assembly 850 may comprise one or more target region with elevated PET-activity levels (to simulate tumor regions), and one or more radiographic films or radiation detector arrays located throughout the cavity 853.
  • the phantom assembly 850 may comprise a plurality of phantom modules 855, some of which may be disc-shaped and comprise one or more target regions 852 and/or background regions that have lower PET activity than the target regions.
  • Films or detector arrays 854 may be located between the phantom modules 855, and may optionally be held in place (e.g., coupled to the modules 855 and/or the housing 851) with spacers or clamps 857.
  • a clamp may comprise a slit or recess through which a film or detector array may be inserted. Each film or detector array may be secured to a location within the cavity using one or more spacers or clamps.
  • a film or detector array 854 may be held in place within the cavity 853 by two co-linear clamps 857 that are aligned along an axis that is orthogonal to a longitudinal axis of the phantom assembly 850. While the volume of the cavity 853 may be occupied by the phantom modules 855, any unoccupied volume of the cavity may be filled with the radioactive and/or positron-emitting fluid. Fluid ingress may be through port 856 while fluid egress may be through port 858.
  • FIG. 8D depicts one variation of a phantom module comprising a housing with a cavity or enclosure volume and a fluid port through which fluid may be introduced or removed from the cavity.
  • the phantom module may comprise one or more radiographic films secured throughout the volume of the cavity or enclosure.
  • the films or detector arrays may be arranged so that the detection plane of the film/detector array is orthogonal to a cross-sectional plane of the module (e.g., as depicted in FIG. 8D) or parallel to a cross-sectional plane of the module (e.g., as depicted in FIG. 8C, co-planar with a cross-sectional plane, etc.).
  • the detection planes of the one or more films or detector arrays may be arranged at an angle with respect to a cross-sectional plane of the module.
  • the phantom module 860 may comprise a housing 862 that defines a cavity or enclosure volume 864 and a fluid port 866.
  • a radioactive fluid (such as any of the fluids described above) may be introduced into and/or withdrawn from the cavity through the fluid port 866.
  • the phantom module may comprise two or more fluid ports, as may be desirable (e.g., to increase the rate of fluid-filling and fluid-emptying).
  • the phantom module 860 may comprise one or more radiographic films or detector arrays 861 that are retained by one or more spacers or retainers 868.
  • the retainers 868 may comprise planar structures that correspond to a cross-sectional geometry of the housing 862 and that are attached to the interior side walls of the housing. Retainers may also comprise shelves with recesses or grooves. The retainers 868 may comprise one or more slits and/or recesses and/or clamps to secure the films and/or detector arrays 861. In contrast to other phantom assemblies or modules (e.g., such as the assembly depicted in FIG. 8C), the majority of the volume of the cavity or enclosure is fluid-fillable such that the fluid flows around the films or detector arrays. The phantom module 860 may not have any target regions, or may have one or more target regions.
  • FIGS. 2-7 depict phantom disks that are arranged or stacked along a
  • phantoms may be arranged or stacked along a transverse axis of an oblong or cylindrical phantom module (i.e., where the transverse axis is orthogonal to the longitudinal axis).
  • phantoms that may be slidably disposed into the generally cylindrical internal volume may be shaped as transverse sections of the internal volume.
  • each of the phantoms may be shaped as hemi-cylinders (i.e., a cylinder that has been cut lengthwise, along/parallel to the longitudinal axis or length of the cylinder).
  • phantom module 900 may comprise a housing 902 having a cylindrical lumen 903 therethrough, a first phantom 904 having a hemi -cylindrical shape disposed within a first portion of the lumen 903, a second phantom 906 having a hemi- cylindrical shape disposed within a second portion of the lumen 903.
  • a radiographic film (or radiation detector array) 908 may be disposed between the first and second phantoms.
  • Each of the first and second phantoms 904, 906 may comprise a background region 910, and one or more target regions 912, which may be PET-avid.
  • the phantoms 904, 906 may comprise a non-target region 914, which may represent an anatomical structure that is radiation-sensitive and should be avoided during a treatment session (e.g., spine, liver, brain).
  • the non-target region 914 may comprise one or more radiographic films or radiation detector arrays to assess the radiation exposure of this region during a treatment session.
  • the phantoms may be shaped as non-symmetric sections of a cylinder (e.g., a cylinder that has been cut lengthwise, but not along the central longitudinal axis).
  • the background regions of the first and second phantoms may comprise a radioactive material (e.g., Ge-68 epoxy or PET tracer, solid or liquid) or may comprise a non-radioactive material (e.g., epoxy, water, acrylic).
  • the module 900 may be coupled to one or more actuators or motors that may be configured to move it laterally according to arrow 920, or to rotate it according to arrow 930. Alternatively or additionally, the module 900 may be mounted on a cradle or curved base that rolls the module 900 along a partial arc or rotates/pivots the module 900 about a central longitudinal axis.
  • FIG. 9B also depicts one variation of a module 900' where the first phantom 904' and the second phantom 906' are shaped as phantoms 904, 906 respectively, but may not comprise any radioactive materials.
  • the module 900' may comprise a radiographic film 908' or radiation detector array between the first and second phantoms 904', 906' . Radiographic films and detectors may be located at other locations throughout the module.
  • Phantom modules 900, 900' to qualify, calibrate, and/or validate a radiation therapy system and treatment plan.
  • a treatment plan may be developed to apply radiation dose to the target regions of module 900.
  • the module 900 may be loaded into the radiation therapy system, where PET emissions from the target regions 912 are detected by the PET detectors and used to update the treatment plan, if needed.
  • the module 900 may be moved in accordance with arrows 920, 930.
  • the module 900 may be replaced with module 900' .
  • Module 900' may be movable in the same way that module 900 is movable within the system. The updated treatment plan is then used to apply radiation to the module 900'.
  • the dose may be measured by the radiographic film 908' .
  • Dose data from the radiographic film 908' may be used to generate a dose map and/or to otherwise verify, calibrate, or qualify the treatment plan, and/or radiation therapy system components.
  • a radiation detector array may comprise an array of diode detectors such as
  • FIG. 11 depicts one variation of a phantom module comprising a plurality of semi-disk shaped phantoms.
  • the phantom module 1100 may comprise a housing 1102 comprising a longitudinal lumen 1103.
  • the lumen 1103 may be cylindrically shaped and sized to retain a plurality of phantoms, some of which may contain background or low levels of PET activity and others which may contain target regions with elevated levels of PET activity.
  • a phantom 1104 may be shaped as a semi-disk, and when multiple semi-disk phantoms 1104 are stacked or assembled together within the lumen 1103, the target regions of each semi-disk phantom may form an overall target region profile (or profiles, if there are multiple target regions).
  • the phantom module 1100 may also comprise one or more radiographic films or detector arrays 1106 located between the semi-disk phantoms. In some variations, one or more films or detector arrays 1106 may be located along a plane that extends along the length of the module 1100 (e.g., that transects the longitudinal lumen 1103).
  • one or more films or detector arrays may be located alone planes that are parallel with the plane(s) of the phantom 1104 (e.g., slices that are orthogonal to the longitudinal axis of the phantom module).
  • a radioactive fluid may be used to fill regions of the longitudinal lumen that are not occupied by a semi -disk phantom (e.g., via a fluid port in the housing).
  • a phantom module may comprise semi -disk phantoms that comprise one or more target regions, and the remainder of the lumen volume that is not occupied by semi-disk phantoms having target regions may be filled with a radioactive fluid.
  • the lumen volume not occupied by semi-disk phantoms having target regions may be occupied by semi-disk phantoms without target regions.
  • the phantom module 1100 may be coupled to one or more motors or actuators that may be configured to move it laterally or to rotate it.
  • FIG. 12A depicts one variation of a phantom assembly 1200 comprising a base 1201 having a first longitudinal lumen 1203a and a second longitudinal lumen 1203b.
  • the base 1201 may comprise a housing that defines a fluid cavity or enclosure volume that surrounds first and second longitudinal lumens 1203a, 1203b.
  • the first and second longitudinal lumens 1203a, 1203b are sized and shaped to correspond with first and second phantom modules 1202, 1202' respectively, such that the phantom modules can be slidably disposed within the lumens.
  • the macro structure or overall geometry of phantom modules 1202, 1202' may be cylindrical, and may each comprise a plurality of phantom portions or segments 1210.
  • the phantom segments 1210 may each be subdivisions of the cylindrical phantom modules 1202, 1202' .
  • the phantom segments 1210 may be shaped as cylinders that have been laterally and
  • each of the phantom segments are quartered cylinders, some of which are segments that are symmetrically-quartered cylinders (e.g., the segments are all the same size, shaped as if a cylinder was quartered symmetrically along orthogonal axes, FIG. 12C), and some of which are segments that are asymmetrically-quartered (e.g., the segments are different sizes, shaped as if a cylinder was quartered symmetrically along one axis, or quartered without any axial symmetry, FIGS. 12A- 12B).
  • the phantom segments 1210 may comprise one or more target regions 1206 that exhibit elevated levels of radioactivity and/or PET-activity, and non-target regions 1208 that exhibit relatively lower levels of radioactivity and/or PET-activity.
  • the non-target regions 1208 may comprise cavity or enclosure volumes that can be filled with radioactive or positron-emitting or non-radioactive fluid, as may be desirable and described above.
  • phantom segments may comprise a housing that defines a cavity or enclosure that may be filled with a radioactive or positron-emitting or non-radioactive fluid, and a fluid port attached to the housing.
  • base 1201 may comprise a third longitudinal lumen that has a size and shape that corresponds to the size and shape of phantom modules 1204.
  • the phantom assembly 1200 may simulate a patient's torso, where the size, shaped and location of the first and second longitudinal lumens and the properties of the phantom modules therein may simulate the relative positioning and dosimetric properties of the lungs.
  • the phantom modules 1202, 1202' may have a mass density that is less than that of water, for example about 20% to about 40% of the mass density value of water.
  • the phantom modules 1204 coupled to the base may simulate the position of the spine relative to the lungs, as well as the dosimetric properties of the spine.
  • the phantom modules 1204 are not radioactive or PET-avid, or have relatively low levels of radioactivity or PET activity.
  • the phantom modules 1204 may also be shaped as quarter cylinders, as described above.
  • One or more radiographic films and/or detector arrays may be located between the phantom module segments, and in some variations, the films or detector arrays may be arranged orthogonally with respect to each other. This orthogonal arrangement may facilitate dose measurements in three orthogonal planes.
  • the films and/or detector arrays may be secured or clamped between the phantom module quarter segments, as depicted in FIGS. 12A and 12B.
  • a first film or detector array 1212 and a second film or detector array 1214 may be located between the phantom module quarter segments 1210, such that the first and second
  • films/detector arrays are orthogonal to each other.
  • a third film or detector array 1212' and a third film or detector array 1214' may be located between the phantom module quarter segments 1210', such that the third and fourth
  • films/detector arrays are orthogonal to each other.
  • One or more films or detector arrays 1205 may be disposed between phantom modules 1204. Films or detector arrays 1205 may be used to measure the irradiation of non-target tissue regions (e.g., spine).
  • the film or detector array 1212, 1212' may have a slit through which the orthogonal film or detector array 1214, 1214' may be inserted.
  • separate films and/or arrays may be used for each surface of the phantom module quarter segment that is adjacent to another phantom module quarter segment.
  • phantom module 1220 comprises four phantom quarter segments 1222a, 1222b, 1222c, 1222d that together form a cylindrical shape.
  • the phantom quarter segments may each have a target region surrounded with a FDG solution or Ge-68 epoxy with relatively low radioactivity or PET-activity, or may not have any target regions and comprise FDG solution or Ge-68 epoxy with low radioactivity or PET-activity.
  • Four films or arrays 1224a, 1224b, 1224c, 1224d may be disposed between the phantom quarter segments and held in place by radially pressing all of the phantom quarter segments together. Films and/or detector arrays may be positioned adjacent to phantom regions where dose measurements are of interest, and secured in those positions using clamps, the phantoms themselves, adhesives, and the like.
  • FIG. 12C depicts one variation of a phantom module 1230 comprising a housing 1232 that defines a cavity or enclosure 1234 that may be filled with a radioactive/PET-avid fluid or epoxy, or a non-radioactive fluid or epoxy, as described previously above, to simulate the dosimetric properties of a non-tumor region. Some variations may comprise a fluid port, while others may not comprise a fluid port.
  • the phantom module 1230 may comprise one or more radiographic films and/or detector arrays 1236, 1238 that are located throughout the internal volume of the housing. The films and/or detector arrays 1236, 128 may be secured at selected locations using clamps, adhesives, and the like.
  • the inner walls of the housing 1232 may comprise slots, grooves, recesses, and/or rails to retaining films and/or detector arrays.
  • the films and/or detector arrays 1236 may be arranged such that they are orthogonal to the films and/or detector arrays 1238, or they may be arranged in any orientation or location based upon the location for which dose/fluence is desired to be measured.
  • the phantom module 1230 may comprise one or more target regions 1240 that exhibit elevated levels of radioactivity and/or PET-activity, to simulate the dosimetric properties of a tumor region.
  • the target region 1240 is spherical.
  • the one or more films and/or detector arrays may transect the tumor region (e.g., as depicted in FIG. 12B) or may not transect the tumor region (e.g., as depicted in FIG. 12C).
  • the phantom module 1230 may optionally be coupled to one or more actuators or motors that may be configured to move it laterally (e.g., translate along its longitudinal axis) or to rotate it (e.g., rotate about its longitudinal axis).

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  • Veterinary Medicine (AREA)
  • Radiology & Medical Imaging (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Pathology (AREA)
  • Biophysics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Radiation-Therapy Devices (AREA)

Abstract

La présente invention concerne des fantômes qui permettent d'étalonner des systèmes de radiothérapie et d'en assurer la qualité et qui comprennent des systèmes de radiothérapie guidée biologiquement qui administrent des doses de rayonnement en réponse à des lignes de réponse de PET détectées en temps réel (LOR). Les fantômes de l'invention sont des fantômes modulaires qui comprennent un boîtier cylindrique ayant une pluralité de disques empilés à l'intérieur et une pluralité de films radiographiques. Certains disques ont une région d'arrière-plan et une région cible, la vitesse d'émission de positrons de la région cible étant supérieure à celle de la région d'arrière-plan. Les disques peuvent être agencés et réagencés à l'intérieur du boîtier pour obtenir la forme de région cible souhaitée.
PCT/US2017/058524 2016-10-28 2017-10-26 Procédés d'assurance et de vérification de la qualité de radiothérapie Ceased WO2018081420A1 (fr)

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US201662414613P 2016-10-28 2016-10-28
US62/414,613 2016-10-28

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RU190308U1 (ru) * 2019-03-04 2019-06-25 Государственное бюджетное учреждение здравоохранения города Москвы "Научно-практический клинический центр диагностики и телемедицинских технологий Департамента здравоохранения города Москвы" (ГБУЗ "НПКЦ ДиТ ДЗМ") Устройство фантома для оценки эффективности алгоритмов и методов подавления артефактов от металлоконструкций при проведении компьютерной томографии
WO2020006507A1 (fr) * 2018-06-29 2020-01-02 The Regents Of The University Of California Fantôme modulaire pour l'évaluation de la performance et de la dose d'imagerie dans une tomodensitométrie à faisceau conique
WO2023000437A1 (fr) * 2021-07-20 2023-01-26 Siemens Shanghai Medical Equipment Ltd. Procédé de détermination de la position longitudinale d'un fantôme combiné, support de stockage lisible par ordinateur et dispositif de tomodensitométrie
US12070623B2 (en) 2018-10-12 2024-08-27 Elekta Ltd. Quality assurance for MR-Linac

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US20150212219A1 (en) * 2012-08-10 2015-07-30 Dixit S.R.L. Phantom and method for verifying the calibration of pet scanners

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020006507A1 (fr) * 2018-06-29 2020-01-02 The Regents Of The University Of California Fantôme modulaire pour l'évaluation de la performance et de la dose d'imagerie dans une tomodensitométrie à faisceau conique
US11642094B2 (en) 2018-06-29 2023-05-09 The Regents Of The University Of California Modular phantom for assessment of imaging performance and dose in cone-beam CT
US12016720B2 (en) 2018-06-29 2024-06-25 The Regents Of The University Of California Modular phantom for assessment of imaging performance and dose in cone-beam CT
US12070623B2 (en) 2018-10-12 2024-08-27 Elekta Ltd. Quality assurance for MR-Linac
US12343566B2 (en) 2018-10-12 2025-07-01 Elekta Ltd. Quality assurance for MR-Linac
RU190308U1 (ru) * 2019-03-04 2019-06-25 Государственное бюджетное учреждение здравоохранения города Москвы "Научно-практический клинический центр диагностики и телемедицинских технологий Департамента здравоохранения города Москвы" (ГБУЗ "НПКЦ ДиТ ДЗМ") Устройство фантома для оценки эффективности алгоритмов и методов подавления артефактов от металлоконструкций при проведении компьютерной томографии
WO2023000437A1 (fr) * 2021-07-20 2023-01-26 Siemens Shanghai Medical Equipment Ltd. Procédé de détermination de la position longitudinale d'un fantôme combiné, support de stockage lisible par ordinateur et dispositif de tomodensitométrie

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