Abstract: Disclosed herein are methods and devices for the acquisition of positron emission (or PET) data in the presence of ionizing radiation that causes afterglow of PET detectors. In one variation, the method comprises adjusting a coincidence trigger threshold of the PET detectors during a therapy session. In one variation, the method comprises adjusting a gain factor used in positron emission data acquisition (e.g., a gain factor used to multiply and/or shift the output(s) of a PET detector(s)) during a therapy session. In some variations, a method for acquiring positron emission data during a radiation therapy session comprises suspending communication between the PET detectors and a signal processor of a controller for a predetermined period of time after a radiation pulse has been emitted by the linac.

Abstract: Described herein are multi-leaf collimators that comprise leaf drive mechanisms. The leaf drive mechanisms can be used in binary multi-leaf collimators used in emission-guided radiation therapy. One variation of a multi-leaf collimator comprises a pneumatics-based leaf drive mechanism. Another variation of a multi-leaf collimator comprises a spring-based leaf drive mechanism having a spring resonator.

Abstract: Described herein are systems and methods for positioning a radiation source with respect to one or more regions of interest in a coordinate system. Such systems and methods may be used in emission guided radiation therapy (EGRT) for the localized delivery of radiation to one or more patient tumor regions. These systems comprise a gantry movable about a patient area, where a plurality of positron emission detectors, a radiation source are arranged movably on the gantry, and a controller. The controller is configured to identify a coincident positron annihilation emission path and to position the radiation source to apply a radiation beam along the identified emission path. The systems and methods described herein can be used alone or in conjunction with surgery, chemotherapy, and/or brachytherapy for the treatment of tumors.

Abstract: Disclosed herein are systems and methods for guiding the delivery of therapeutic radiation using incomplete or partial images acquired during a treatment session. A partial image does not have enough information to determine the location of a target region due to, for example, poor or low contrast and/or low SNR. The radiation fluence calculation methods described herein do not require knowledge or calculation of the target location, and yet may help to provide real-time image guided radiation therapy using arbitrarily low SNR images.

Abstract: Disclosed herein are systems and methods for monitoring calibration of positron emission tomography (PET) systems. In some variations, the systems include an imaging assembly having a gantry comprising a plurality of positron emission detectors. A housing may be coupled to the gantry, and the housing may include a bore and a radiation source holder spaced away from a patient scan region within the bore. A processor may be configured to receive positron emission data from the positron emission detectors and to distinguish the positron emission data from the radiation source holder and from the patient scan region. A fault signal may be generated when the positron emission data from the radiation source holder exceeds one or more threshold parameters or criteria.

Abstract: Systems and methods for shuttle mode radiation delivery are described herein. One method for radiation delivery comprises moving the patient platform through the patient treatment region multiple times during a treatment session. This may be referred to as patient platform or couch shuttling (i.e., couch shuttle mode). Another method for radiation delivery comprises moving the therapeutic radiation source jaw across a range of positions during a treatment session. The jaw may move across the same range of positions multiple times during a treatment session. This may be referred to as jaw shuttling (i.e., jaw shuttle mode). Some methods combine couch shuttle mode and jaw shuttle mode. Methods of dynamic or pipelined normalization are also described.

Abstract: An apparatus comprising a radiation source, coincident positron emission detectors configured to detect coincident positron annihilation emissions originating within a coordinate system, and a controller coupled to the radiation source and the coincident position emission detectors, the controller configured to identify coincident positron annihilation emission paths intersecting one or more volumes in the coordinate system and align the radiation source along an identified coincident positron annihilation emission path.

Abstract: Described herein are methods for fluence map generation or fluence map optimization (FMO) for radiation therapy. One variation of a method for generating a fluence map comprises smoothing out nondifferentiable penalty functions and using an accelerated proximal gradient method (e.g., FISTA) to compute a fluence map that may be used by a radiotherapy system to apply a selected dose of radiation to one or more regions of interest (ROI) or volumes of interest (VOI).

Abstract: Systems and methods for shuttle mode radiation delivery are described herein. One method for radiation delivery comprises moving the patient platform through the patient treatment region multiple times during a treatment session. This may be referred to as patient platform or couch shuttling (i.e., couch shuttle mode). Another method for radiation delivery comprises moving the therapeutic radiation source jaw across a range of positions during a treatment session. The jaw may move across the same range of positions multiple times during a treatment session. This may be referred to as jaw shuttling (i.e., jaw shuttle mode). Some methods combine couch shuttle mode and jaw shuttle mode. Methods of dynamic or pipelined normalization are also described.

Abstract: Disclosed herein are methods and devices for the acquisition of positron emission (or PET) data in the presence of ionizing radiation that causes afterglow of PET detectors. In one variation, the method comprises adjusting a coincidence trigger threshold of the PET detectors during a therapy session. In one variation, the method comprises adjusting a gain factor used in positron emission data acquisition (e.g., a gain factor used to multiply and/or shift the output(s) of a PET detector(s)) during a therapy session. In some variations, a method for acquiring positron emission data during a radiation therapy session comprises suspending communication between the PET detectors and a signal processor of a controller for a predetermined period of time after a radiation pulse has been emitted by the linac.

Abstract: Disclosed herein are variations of megavoltage (MV) detectors that may be used for acquiring high resolution dynamic images and dose measurements in patients. One variation of a MV detector comprises a scintillating optical fiber plate, a photodiode array configured to receive light data from the optical fibers, and readout electronics. In some variations, the scintillating optical fiber plate comprises one or more fibers that are focused to the radiation source. The diameters of the fibers may be smaller than the pixels of the photodiode array. In some variations, the fiber diameter is on the order of about 2 to about 100 times smaller than the width of a photodiode array pixel, e.g., about 20 times smaller. Also disclosed herein are methods of manufacturing a focused scintillating fiber optic plate.

Abstract: Described here are systems, devices, and methods for imaging and radiotherapy procedures. Generally, a radiotherapy system may include a radiotransparent patient platform, a radiation source coupled to a multi-leaf collimator, and a detector facing the collimator. The radiation source may be configured to emit a first beam through the collimator to provide treatment to a patient on the patient platform. A controller may be configured to control the radiotherapy system.

Abstract: Disclosed herein are radiation therapy systems and methods. These radiation therapy systems and methods are used for emission-guided radiation therapy, where gamma rays from markers or tracers that are localized to patient tumor regions are detected and used to direct radiation to the tumor. The radiation therapy systems described herein comprise a gantry comprising a rotatable ring coupled to a stationary frame via a rotating mechanism such that the rotatable ring rotates up to about 70 RPM, a radiation source (e.g., MV X-ray source) mounted on the rotatable ring, and one or more PET detectors mounted on the rotatable ring.

Abstract: Described herein are systems and methods for positioning a radiation source with respect to one or more regions of interest in a coordinate system. Such systems and methods may be used in emission guided radiation therapy (EGRT) for the localized delivery of radiation to one or more patient tumor regions. These systems comprise a gantry movable about a patient area, where a plurality of positron emission detectors, a radiation source are arranged movably on the gantry, and a controller. The controller is configured to identify a coincident positron annihilation emission path and to position the radiation source to apply a radiation beam along the identified emission path. The systems and methods described herein can be used alone or in conjunction with surgery, chemotherapy, and/or brachytherapy for the treatment of tumors.

Abstract: Disclosed herein are systems and methods for guiding the delivery of therapeutic radiation using incomplete or partial images acquired during a treatment session. A partial image does not have enough information to determine the location of a target region due to, for example, poor or low contrast and/or low SNR. The radiation fluence calculation methods described herein do not require knowledge or calculation of the target location, and yet may help to provide real-time image guided radiation therapy using arbitrarily low SNR images.

Abstract: Described herein are systems and methods for positioning a radiation source with respect to one or more regions of interest in a coordinate system. Such systems and methods may be used in emission guided radiation therapy (EGRT) for the localized delivery of radiation to one or more patient tumor regions. These systems comprise a gantry movable about a patient area, where a plurality of positron emission detectors, a radiation source are arranged movably on the gantry, and a controller. The controller is configured to identify a coincident positron annihilation emission path and to position the radiation source to apply a radiation beam along the identified emission path. The systems and methods described herein can be used alone or in conjunction with surgery, chemotherapy, and/or brachytherapy for the treatment of tumors.

Abstract: Systems and methods for shuttle mode radiation delivery are described herein. One method for radiation delivery comprises moving the patient platform through the patient treatment region multiple times during a treatment session. This may be referred to as patient platform or couch shuttling (i.e., couch shuttle mode). Another method for radiation delivery comprises moving the therapeutic radiation source jaw across a range of positions during a treatment session. The jaw may move across the same range of positions multiple times during a treatment session. This may be referred to as jaw shuttling (i.e., jaw shuttle mode). Some methods combine couch shuttle mode and jaw shuttle mode. Methods of dynamic or pipelined normalization are also described.

Abstract: Disclosed herein are systems and methods for monitoring calibration of positron emission tomography (PET) systems. In some variations, the systems include an imaging assembly having a gantry comprising a plurality of positron emission detectors. A housing may be coupled to the gantry, and the housing may include a bore and a radiation source holder spaced away from a patient scan region within the bore. A processor may be configured to receive positron emission data from the positron emission detectors and to distinguish the positron emission data from the radiation source holder and from the patient scan region. A fault signal may be generated when the positron emission data from the radiation source holder exceeds one or more threshold parameters or criteria.

Abstract: Described herein are multi-leaf collimators that comprise leaf drive mechanisms. The leaf drive mechanisms can be used in binary multi-leaf collimators used in emission-guided radiation therapy. One variation of a multi-leaf collimator comprises a pneumatics-based leaf drive mechanism. Another variation of a multi-leaf collimator comprises a spring-based leaf drive mechanism having a spring resonator.

Abstract: Described herein are methods for monitoring the radiation delivery during a radiotherapy delivery session and providing a graphical representation of radiation delivery to an operator (e.g., a clinician, a medical physicist, a radiation therapy technologist). The graphics are updated in real-time, as radiation data is collected by the radiotherapy system, and in some variations, can be updated every 15 minutes or less. A variety of graphical representations (“graphics”) can be used to indicate the status of radiation delivery relative to the planned radiation delivery. Methods optionally include calculating a range of acceptable metric values, generating graphics that represent the range of acceptable metrics values, and generating a graphic that depicts the real-time values of those metrics overlaid with the range of acceptable metrics values.