Apparatus and method for radiotherapy using a radioactive source wire having a magnetic insert
AssigneeAdvanced Cardiovascular Systems, Inc.
InventorRichard T. Thornton
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Abstract
A radiotherapy apparatus is disclosed in which a radioactive-tipped source wire is accurately and precisely positioned within an implantable catheter. Embedded within the source wire, adjacent to its distal tip, is a ferrous ball, and a special magnetic sensor assembly is configured to sense the retraction of the source wire to a predetermined home position by sensing the proximity of the embedded ferrous ball.
Claims19
Radiotherapy apparatus for use in irradiating a selected portion of a lumen of a patient, comprising:
- a catheter sized to be insertable into a patient lumen, the catheter having a lumen extending along substantially its entire length;
- a source wire sized to be slidably insertable into the lumen of the catheter, the source wire including a first segment at or near a distal end thereof, formed of a material that emits radiation, and further including a second segment at or near the distal end thereof, formed of a material having relatively high magnetic permeability;
- an afterloader configured to controllably position the source wire within the lumen of the catheter, with the first segment of the source wire at a selected location, and to withdraw the source wire from the lumen of the catheter, into a predetermined location within the afterloader;
- and
- a magnetic sensor associated with the afterloader, for sensing the presence of the second segment of the source wire at a predetermined home position within the afterloader.
A radiation source wire suitable for use in combination with a catheter insertable into a lumen of a patient, the catheter having a lumen extending along substantially its entire length, the radiation source wire comprising:
- an elongated wire sized and configured to be insertable into the lumen of the catheter, the wire being formed of a nonmagnetic material;
- a source of radiation located at or near a distal end of the elongated wire;
- and
- a magnetic material located at or near the distal end of the elongated wire, adjacent to the source of radiation, wherein proximity of the magnetic material can be sensed, to provide an indication of the position of the source wire within the lumen of the catheter.
A method for irradiating a prescribed region of a lumen of a patient, comprising:
- inserting a catheter into the patient lumen, the catheter having a lumen extending along substantially its entire length;
- providing a nonmagnetic source wire that carries a source of radiation at or near its distal tip and that further carries a magnetic material at or near its distal tip, adjacent to the source of radiation;
- and
- controllably inserting the source wire to a prescribed position within the lumen of the catheter, wherein controllably inserting includes sensing the presence of the source wire at a predetermined home position using a magnetic sensor sensitive to the magnetic material carried at or near the source wire's distal tip.
Dependencies are inferred from the claim text.