RefleXion Medical, Inc.

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.

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.

Disclosed herein are methods for determining the location of a moving target region (e.g., a tumor) based on the location of the center of its range of motion and the location of a target region surrogate, during a radiotherapy treatment session or a quality assurance (QA) session. These methods comprise characterizing the motion range of the target region, calculating the location of the center of the motion range, and determining a correlation between the position of the target region surrogate and the displacement of the target region from the center of the motion range as the target region moves.

Described herein are variations of a radiotherapy patient motion detection system. For example, a patient motion detection system may include a sensor coupled to a patient support platform for use in measuring patient motion during a radiotherapy treatment session. The motion sensor may transmit measurements to a controller for processing and subsequent use in timing delivery of radiation to a treatment region of interest within a patient. Also described herein are methods of use of a patient motion detection system.

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.

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.

This application relates to methods for delivering radiation to a positron-emitting target within a subject under continuous PET guidance. Instead of directing radiation at a collinear path along each detected positron line-of-response (LOR), the methods generally include detecting a pattern of LORs that intersect the target. In response to the pattern, radiation may be delivered along paths that are not necessarily collinear to any of the LORs. Methods for further modifying radiation delivery as well as the detected LOR population are also described.

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.

A radiation therapy system comprising a therapeutic radiation system (e.g., an MV X-ray source, and/or a linac) and a co-planar imaging system (e.g., a kV X-ray system) on a fast rotating ring gantry frame. The therapeutic radiation system and the imaging system are separated by a gantry angle, and the gantry frame may rotate in a direction such that the imaging system leads the MV system. The radiation sources of both the therapeutic and imaging radiation systems are each collimated by a dynamic multi-leaf collimator (DMLC) disposed in the beam path of the MV X-ray source and the kV X-ray source, respectively. In one variation, the imaging system identifies patient tumor(s) positions in real-time. The DMLC for the imaging radiation source limits the kV X-ray beam spread to the tumor(s) and/or immediate tumor regions, and helps to reduce irradiation of healthy tissue (e.g., reduce the dose-area product).

Described herein are methods and systems for generating a MV detector image for evaluating the quality of radiation delivery according to a radiotherapy treatment plan. The MV detector image is generated from MV detector measurements of a small number of multi-leaf collimator (MLC) leaf openings.