Ring gantry radiation treatment delivery system with dynamically controllable inward extension of treatment head

A method for image guided radiation treatment (IGRT) of a body part of a patient, comprising:

• positioning the patient along a longitudinal axis of an IGRT apparatus, the IGRT apparatus comprising:
• a ring gantry having a central opening sufficiently large to accommodate the body of the patient;
• a gantry tilting mechanism configured to tilt said ring gantry to a plurality of different tilt angles relative to said longitudinal axis;
• and
• a radiation treatment head coupled to said ring gantry and rotatable around said central opening in at least a 180 degree arc, wherein said radiation treatment head is mechanically coupled to said ring gantry such that a distance by which the radiation treatment head extends inwardly toward the central opening relative to the ring gantry is dynamically controllable;
• and
• operating the IGRT apparatus to apply non-coplanar radiation treatment to the body part during a treatment fraction, said operating comprising rotating the radiation treatment head around said central opening to a plurality of different gantry angles, said operating further comprising tilting said ring gantry to the plurality of different tilt angles relative to said longitudinal axis.

A radiation treatment apparatus, comprising:

• a ring gantry having a central opening sufficiently large to accommodate a body of a patient positioned along a longitudinal axis and extending therethrough;
• and
• a radiation treatment head coupled to said ring gantry and rotatable around said central opening in at least a 180 degree arc;
• wherein said radiation treatment head is mechanically coupled to said ring gantry such that a distance by which the radiation treatment head extends inwardly toward the central opening relative to the ring gantry is dynamically controllable.

A method for image guided radiation treatment (IGRT) of a body part of a patient, comprising:

• positioning the patient along a longitudinal axis of an IGRT apparatus, the IGRT apparatus comprising:
• a ring gantry having a central opening sufficiently large to accommodate the body of the patient;
• and
• a radiation treatment head coupled to said ring gantry and rotatable around said central opening in at least a 180 degree arc, wherein said radiation treatment head is mechanically coupled to said ring gantry such that a distance by which the radiation treatment head extends inwardly toward the central opening relative to the ring gantry is dynamically controllable;
• and
• operating the IGRT apparatus to apply radiation treatment to the body part during a treatment fraction, said operating comprising rotating the radiation treatment head around said central opening to a plurality of different gantry angles, said operating further comprising dynamically controlling said distance by which the radiation treatment head extends inwardly for said plurality of gantry angles.