Methods and devices for detecting, controlling, and predicting radiation delivery

A system for treating a target area in a patient with an irradiation beam, comprising:

• (a) a tracking assembly for tracking the position of a patient body region containing the target area and at least one radiation-sensitive area with respect to a known reference axis in an external coordinate system;
• (b) a X-ray beam source for directing an irradiation beam at the patient target area along a known treatment axis in the external coordinate system;
• and
• (c) a processor operatively connected to the tracking assembly and beam source, and configured to:
• (i) determine, from the known position of body region in the external coordinate system, the coordinates of the target area to be treated and the coordinates of the at least one radiation-sensitive patient structure;
• (ii) during a period when the irradiation beam is being directed along the treatment axis at the target area, and based on information received from the tracking assembly, track the positions of the target area to be treated and the at least one radiation-sensitive structure;
• (iii) based on the known beam axis of the collimated beam in the external coordinate system, and the instantaneous positions of the target area to be treated and the at least one radiation-sensitive structure, calculate a total radiation equivalent received at the target area and at least one radiation-sensitive structure;
• and
• (iv) based on the calculated radiation equivalents from step (iii), control the irradiation beam to insure that the at least one radiation-sensitive structure does not receive more than a preselected radiation equivalent during the treatment.

Non-transitory machine-readable medium operable with an electronic computer, in monitoring the total radiation dose received at a target site during the course of treatment in which the target site is irradiated with a collimated x-radiation, to perform the steps comprising:

• (a) defining, in an external coordinate system, coordinates for (i) a reference axis, (ii) a radiation-beam axis, and (iii) the target site which, when a body axis having a known relationship to the target site is aligned with the reference axis, places the radiation beam at the center of the target area,
• (b) receiving from a body tracking device, ongoing information during the course of radiation treatment on the position of the body axis with respect to the reference axis,
• (c) from the information received in step (b), and from the known intensity of the beam at the radiation beam, calculating the spatial distribution of radiation received in the region of the target site over the course of the treatment, and
• (d) using the spatial distribution of radiation calculated in step (c) to monitor the total radiation dose at the target site over the course of the treatment.

Non-transitory machine-readable medium operable with an electronic computer, in controlling the treatment of an ocular lesion by exposing the lesion to a collimated x-radiation beam, to perform the steps comprising:

• (a) using information received from an eye-tracking system to determine a geometric axis of the eye in an external coordinate system,
• (b) with the geometric axis of the eye placed in alignment with a reference axis, determining the coordinates of the lesion in an external coordinate system,
• (c) from the coordinates of the ocular lesion determined in step (b), determining a beam axis that intersects the lesion with the patient eye in an defined position with respect to the reference axis, and
• (d) controlling the position of an x-ray beam source to position the beam along the beam axis determined in step (c).

A computer-executed method for use in an X-ray radiation treatment device including a computer processor and a body-part motion tracking device operably connected to the computer processor, the tracking device including a body-contact member configured to engage the surface of a body part of the patient which includes a radiation treatment target, and a camera configured to capture an electronic image of the body part, the processor effective to execute instructions to perform the steps comprising:

• (a) determining an initial position and orientation of the body part, based on:
• (i) determining the alignment of the contact member as engaged with the body so as to have a known orientation relative to an anatomical axis of the body part and a known position relative to the contacted body surface;
• and
• (ii) determining the alignment of the contact member as engaged with the body with the radiation treatment device so as to have a known initial position and orientation in a coordinate system of the radiation treatment device;
• (b) determining an initial position of the treatment target in the coordinate system of the radiation treatment device, based on determining the relative position of the treatment target to the contact member;
• (c) electronically capturing a plurality of time-sequenced images including the contact member while engaged with the body during the administration of radiation treatment;
• (d) processing the images in the computer processor so as to determine one or both of an orientation and a position of the contact member in the coordinate system of the radiation treatment device at the time of capture of each image;
• and
• (e) determining for each image, from the orientation and/or position of the contact member at the time of capture of the image, the change from the initial orientation and/or position of the contact member in the coordinate system of the radiation treatment device;
• and
• (f) determining for each image, the change from the initial position of the treatment target in the coordinate system of the radiation treatment device, so as to track the sequential motion of the treatment target;
• and
• (g) controlling at least one aspect of the radiation treatment based on the tracking of the sequential motion of the treatment target.