IMPLANT FOR TARGETING THERAPEUTIC PROCEDURE

1 . A method for treating a proliferative tissue disease in a patient comprising:

excising diseased tissue from the patient and thereby creating a tissue cavity;

placing a bioabsorbable implant within the tissue cavity, the implant having a predetermined shape and including means for visualizing the implant;

determining the location of the implant within the patient; and

treating tissue surrounding the tissue cavity with therapeutic energy sources.

2 . The method of claim 1 , wherein the implant comprises collagen.

3 . The method of claim 1 , wherein the implant has a density that is less than the density of soft tissue.

4 . The method of claim 1 , wherein the implant is in the shape of a sphere.

5 . The method of claim 1 , wherein the treating of tissue with energy sources comprises applying external beam radiation.

6 . The method of claim 1 , wherein the implant is sized to substantially fill the tissue cavity.

7 . The method of claim 1 , wherein the implant substantially maintains its predetermined shape for a period of about at least six weeks.

8 . The method of claim 1 , wherein a diameter of the implant is approximately 2 to 4 centimeters.

9 . A method for targeting and delivering therapeutic rays to a patient's soft tissue, comprising:

(a) imaging an implanted device within soft tissue in the patient, the implanted device being substantially rigid, having a predetermined shape, and having a density that is lower than a density of the patient's soft tissue;

(b) determining a region of target tissue surrounding the implanted device;

(c) targeting an energy source from external to the patient to the target tissue; and

(d) delivering the targeted energy dose.

10 . The method of claim 9 , further comprising:

without removing the implanted device or acting to alter its configuration, repeating, following the passage of time, steps (a) through (d).

11 . The method of claim 9 , wherein the implanted device has a density of less than or equal to about 1.03 g/cc.

12 . The method of claim 9 , wherein the implanted device is implanted in a resected tumor cavity.

13 . The method of claim 12 , wherein the implanted device is implanted in a patient's breast.

14 . The method of claim 10 , wherein the implanted device is bioabsorbable.

15 . The method of claim 14 , wherein the implanted device remains substantially rigid during the delivery of the targeted radiation doses before absorbing.

16 . The method of claim 9 , further comprising providing fiducial markers in or on the device in order to track the device's position.

17 . The method of claim 9 , further comprising delivering to the patient a treatment material from the implanted device.

18 . A system for targeting energy sources to target tissue surrounding a tumor resection cavity comprising:

an implantable device having a body;

the body being substantially rigid and having a predetermined shape; the body further being bioabsorbable and having a density less than or equal to about 1.03 g/cc;

wherein the implantable device can be implanted in a resected cavity in soft tissue and cause the cavity to conform to the predetermined shape, the implantable device further being imageable due to its density being less than that of soft tissue such that the boundaries of the tissue corresponding to the predetermined shape can be determined.

19 . The system of claim 18 , wherein the body includes a first bioabsorbable material covering a second bioabsorbable material, the two bioabsorbable materials having differing absorption characteristics.

20 . The system of claim 19 wherein the outer material is from the family of bioabsorbable sutures and the inner material is from the collagen family of materials.

21 . The system of claim 18 , further comprising an imaging means for determining the location of the predetermined shape in soft tissue and a delivery means for targeting and delivering therapeutic rays to target tissue surrounding the predetermined shape.