Radiation therapy system with constrained rotational freedom
AssigneeWisconsin Alumni Research Foundation
InventorsStuart Swerdloff, Thomas Rockwell Mackie, Timothy Holmes
Life of this patent
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Abstract
A radiation therapy machine has a constrained angular freedom to produce a beam only within a gantry plane. A radiation shield may be stationary and not attached to the gantry or rotating to always block the primary beam. The constrained motion reduces the risk of patient/gantry collision and provides for extremely accurate radiation therapy planning. The therapy machine, so constrained, may include a tomographic imaging system on a single gantry. The two systems cooperate and employ many of the same hardware components to both plan and carry out therapy sessions in which irregularly shaped treatment volumes are accurately irradiated while tissue surrounding those volumes is minimally irradiated.
Claims4
A radiation therapy machine for treating a patient with high energy radiation comprising:
- a gantry for rotation within a gantry plane;
- a table disposed along an axis of translation for supporting a patient and for moving the patient along the axis of translation, the axis of translation positioned within the rotation of the gantry;
- a radiation source disposed on the gantry for producing a radiation beam within a fan beam plane substantially parallel to the gantry plane, the beam including a plurality of rays diverging in the beam plane about one central ray, the central ray directed at the patient from a variety of gantry angles along the gantry plane;
- and
- an attenuation means disposed between the radiation source and the patient for independently controlling the intensity of each ray as a function of gantry angle, the attenuation means including:
- a plurality of radiation attenuating leaves;
- a supporting member positioned generally between the radiation source and the patient for guiding the leaves between a closed state within the radiation beam, each leaf thus occluding one ray of the beam, and an open state outside of the radiation beam to allow unobstructed passage of the ray;
- motivation means for independently moving each leaf between the open and closed states;
- and
- timing means communicating with the motivation means for controlling the ratio of the period of time during which each leaf is in the closed state to the period during which each leaf is in the open state to control the average energy fluence of each ray of the beam.
Dependencies are inferred from the claim text.