System for monitoring the geometry of a radiation treatment apparatus, trackable assembly, program product, and related methods

A system to monitor a geometry of a treatment apparatus, the system comprising:

• an application computer having a memory associated therewith, and a treatment plan stored in the memory to provide treatment delivery instructions;
• a treatment apparatus, in communication with the application computer, to provide radiation treatment to the patient, the radiation treatment apparatus including:
• a radiation emitter positioned to emit a radiation beam, and
• a rotating assembly to direct a radiation beam having a beam axis through a target of the patient and having a rotational path in a distinct plane and an axis of rotation, the axis of rotation of the rotating assembly intersecting the beam axis at a three-dimensional coordinate to define an isocenter of an isocenter coordinate system of the treatment apparatus;
• a trackable body fixedly connected to a preselected portion of the rotating assembly at a predetermined trackable body offset position relative to a predetermined three-dimensional coordinate position of the isocenter, the trackable body having a plurality of separate and spaced-apart indicators each connected at a separate preselected position thereon and adapted to be tracked to indicate a separate three-dimensional coordinate position of each indicator of the plurality of indicators;
• and
• an apparatus to track a trackable body, the apparatus comprising:
• a trackable body detector having a detector body positioned spaced apart from the treatment apparatus and having a receiver positioned to receive energy provided by a subset of the plurality of indicators, to thereby detect three-dimensional positions and to produce a plurality of position signals indicating three-dimensional coordinate positions of the subset of the plurality of indicators, and
• a determiner, in communication with the trackable body detector and responsive to the plurality of position signals produced by the detector, to determine the three-dimensional coordinate positions of the subset of the plurality of indicators, to thereby determine the three-dimensional coordinate position of the isocenter of the treatment apparatus and to thereby determine, when so existing, a possible isocenter coordinate system definition failure.

A trackable assembly comprising:

• a first trackable body adapted to be fixedly connected to a preselected portion of a rotating assembly of an apparatus located at a predetermined offset reference position relative to a predetermined three-dimensional coordinate system definition of an isocenter of an isocenter coordinate system of the apparatus and located along a rotational path of a preselected portion of the rotating assembly, the first trackable body having a first set of a plurality of separate and spaced-apart indicators each connected at a separate preselected position thereon to indicate a separate three-dimensional coordinate position of each indicator in the first set of the plurality of indicators, to thereby provide three-dimensional positional data and orientation data of the first trackable body, the first trackable body adapted to be tracked by an apparatus to track a trackable body over a subset of possible first trackable body positions and orientations to provide a fixed positional reference to the three-dimensional coordinate system definition of the isocenter;
• and
• a second trackable body having a proximal body end portion pivotally connected to or adjacent the first trackable body, a free-moving distal body end portion, a medial body portion connected to and extending between the proximal body end portion and the distal body end portion, and having a second set of a plurality of separate and spaced-apart indicators each connected at a separate preselected position thereon to indicate a separate three-dimensional coordinate position of each indicator in the second set of the plurality of indicators, to thereby provide three-dimensional position data and orientation data of the second trackable body, the second trackable body adapted to be tracked by the apparatus to track a trackable body over a subset of possible second trackable body positions and orientations to provide a substantially fixed reference orientation to the apparatus to track a trackable body.

Geometry analyzing program product stored on a storage media to analyze a geometry of a radiation treatment apparatus having a rotating assembly during radiation delivery so that a treatment plan can be more accurately applied to a patient, the program product comprising:

• a trackable body position and orientation determiner, adapted to receive a plurality of position signals produced by a trackable body detector and indicating a separate three-dimensional coordinate position of a first and a second set of a plurality of trackable indicators connected respectively to a first and a second trackable body, to determine a three-dimensional coordinate first trackable body position and first trackable body orientation of the first trackable body, and to determine a respective second trackable body orientation of the second trackable body;
• an isocenter position and orientation determiner, responsive to the determined first trackable body position, the determined first trackable body orientation, the determined second trackable body orientation, and responsive to a predetermined transform matrix indicating a transform magnitude, direction, and magnitude between a predetermined first trackable body reference coordinate system and a predetermined isocenter coordinate system of the treatment apparatus, to determine a respective three-dimensional coordinate system definition of an isocenter of the isocenter coordinate system and to determine an angular difference between the first trackable body orientation and the second trackable body orientation, the angular difference indicating an angle of rotation of the rotating assembly, to thereby determine an orientation of the isocenter coordinate system for the treatment apparatus independent of the angle of rotation of the rotating assembly;
• a deviation detector, responsive to at least one of the trackable body position and orientation determiner and the isocenter position and orientation determiner, to detect a deviation in the geometry of the rotating assembly, when so existing, such deviation indicating a possible isocenter coordinate system definition failure;
• and
• a deviation responder, responsive to detection of the deviation, when so existing, to respond to such deviation during application of the treatment plan by signaling an existence of a possible isocenter coordinate system definition failure.

A computer readable medium that is readable by a computer to monitor a geometry of an apparatus having a rotating assembly, the computer readable medium comprising a set of instructions that, when executed by the computer, cause the computer to perform the following operations:

• receiving a plurality of position signals produced by a trackable body detector and indicating a separate three-dimensional coordinate position of a plurality of trackable indicators connected respectively to a trackable body;
• determining a three-dimensional coordinate trackable body position of the trackable body, responsive to the plurality of position signals;
• receiving a predetermined transform matrix indicating a transform magnitude, direction, and rotation between a predetermined trackable body reference coordinate system and a predetermined isocenter coordinate system of the apparatus;
• and
• responsive to the determined trackable body position and the predetermined transform matrix, determining a respective a three-dimensional coordinate system definition of the isocenter of the apparatus.

A computer readable medium that is readable by a computer to monitor during patient treatment delivery a geometry of a treatment apparatus having a rotating assembly, the computer readable medium comprising a set of instructions that, when executed by the computer, cause the computer to perform the following operations:

• receiving a plurality of position signals produced by a trackable body detector and that indicate a separate three-dimensional coordinate position of a plurality of separate and spaced-apart trackable indicators connected to a trackable body positioned along a rotational path of the rotating assembly;
• determining during patient treatment delivery a three-dimensional coordinate trackable body position of the trackable body, responsive to the plurality of position signals;
• receiving a predetermined transform matrix indicating a transform between a predetermined trackable body coordinate system of the trackable body and a predetermined isocenter coordinate system of the treatment apparatus;
• and
• determining an at least one three-dimensional coordinate position of the isocenter, responsive to the determined three-dimensional coordinate position of the trackable body and the predetermined transform matrix.

A method of monitoring a geometry of a treatment apparatus having a rotating assembly so that a treatment plan can be more accurately applied to a patient, the method comprising the steps of:

• connecting a trackable body to a preselected portion of the rotating assembly located at a predetermined offset position relative to a predetermined three-dimensional coordinate position of an isocenter of the treatment apparatus;
• sampling and analyzing at least one position of the trackable body along a rotational path of the rotating assembly to detect a deviation in the geometry of the rotating assembly, when so existing, during application of the treatment plan, to thereby verify a definition of the isocenter coordinate system determined with reference to the trackable body;
• and
• signaling an existence of a possible isocenter coordinate system definition failure, responsive to detection of the deviation.