Tissue site markers for in vivo imaging

• US 7,565,191 B2
• Filed: 09/29/2005
• Issued: 07/21/2009
• Est. Priority Date: 02/02/1999
• Status: Expired due to Fees

• Current Assignee: Senorx Incorporated (Becton, Dickinson & Co)
• Original Assignee: Senorx Incorporated (Becton, Dickinson & Co)
• Inventors: De Santis, Stephen A., Jones, Michael L., Burbank, Fred H., Quick, Richard L., Lubock, Paul, Louw, Frank
• Primary Examiner(s): PELHAM, JOSEPH MOORE
• Application Number:
  US11/238,201
• Publication Number:
  US 20060036165A1
• Time in Patent Office: 1,391 Days
• Field of Search: None
• US Class Current: 600/431
• CPC Class Codes: A61B 10/02 Instruments for taking cell samples or for biopsy A61B10/0038 and A61B10/0045 take precedence; needle locating or guiding means A61B17/3403; samplers for enzymology or microbiology C12M1/26; sampling or preparing biological specimens G01N33/48
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61B 2090/08021 of the patient or his organs
• CPC Class Codes: A61B 2090/3908 Soft tissue, e.g. breast tissue
• CPC Class Codes: A61B 2090/3925 ultrasonic
• CPC Class Codes: A61B 2090/3987 Applicators for implanting markers
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: A61B 8/0833 involving detecting or locating foreign bodies or organic structures
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61K 49/006 Biological staining of tissues in vivo, e.g. methylene blue or toluidine blue O administered in the buccal area to detect epithelial cancer cells, dyes used for delineating tissues during surgery
• CPC Class Codes: A61K 49/222 characterised by a special physical form, e.g. emulsions, liposomes
• CPC Class Codes: A61M 37/0069 Devices for implanting pellets, e.g. markers or solid medicaments for introducing of radioactive sources for interstitial radiation therapy, i.e. brachytherapy A61N5/1027

Abstract

The invention is directed biopsy site markers and methods of marking a biopsy site, so that the location of the biopsy cavity is readily visible by conventional imaging methods, particularly by ultrasonic imaging. The biopsy site markers of the invention have high ultrasound reflectivity, presenting a substantial acoustic signature from a small marker, so as to avoid obscuring diagnostic tissue features in subsequent imaging studies, and can be readily distinguished from biological features. The several disclosed embodiments of the biopsy site marker of the invention have a high contrast of acoustic impedance as placed in a tissue site, so as to efficiently reflect and scatter ultrasonic energy, and preferably include gas-filled internal pores. The markers may have a non-uniform surface contour to enhance the acoustic signature. The markers have a characteristic form which is recognizably artificial during medical imaging. The biopsy site marker may be accurately fixed to the biopsy site so as to resist migration from the biopsy cavity when a placement instrument is withdrawn, and when the marked tissue is subsequently moved or manipulated.

Claims

1. An assembly for marking a selected intracorporeal site within tissue of a patient, comprising:

a) a delivery tube having a distal end, a distal portion proximal to the distal end, a discharge opening in the distal portion and an inner lumen extending to the discharge opening;

b) a plurality of marker bodies which are slidably disposed within the inner lumen of the delivery tube and which are formed at least in part of bioabsorbable material that dissipates over time at the intracorporeal tissue site; and

c) at least one marker body which is slidably disposed within the inner lumen of the delivery tube and which is formed at least in part of sintered metallic material, which is recognizably artificial when the marker body is remotely imaged and which is persistent at the intracorporeal site.

2. The assembly of claim 1 including a ramp within the distal portion of the delivery tube which is inclined to the elongated discharge port and which is configured to discharge marker bodies out of the discharge port and a plunger which is slidably disposed in part within the inner lumen of the delivery cannula proximal to the marker bodies and which is configured to move the marker bodies up the ramp and out of the discharge port in the delivery cannula.

3. The assembly of claim 2 wherein a plunger is slidably disposed within the inner lumen of the delivery tube proximal to the plurality of marker bodies, so that distal movement of the plunger will move marker bodies up the ramp and out of the discharge opening in the delivery cannula.

4. The assembly of claim 1 wherein the marker bodies formed of bioabsorbable material have transverse dimensions of about 0.5 to about 5 mm.

5. The assembly of claim 4 wherein the marker bodies formed of bioabsorbable material have longitudinal dimensions of about 1 to about 10 times the transverse dimensions thereof.

6. The assembly of claim 1 wherein marker bodies formed of bioabsorbable material have cylindrical shapes.

7. The assembly of claim 1 wherein the sintered metallic marker body has a porous structure.

8. The assembly of claim 7 wherein the sintered porous structure has a pore size of about 1 to about 100 micrometers.

9. The assembly of claim 8 wherein the porous marker body has a pore size of about 5 to about 40 micrometers.

10. The assembly of claim 1 wherein the bloabsorbable material is selected from the group consisting of gelatin, collagen, polylactic acid, polyglycolic acid, polylactic-polyglycolic acid co-polymer, polycapriolactone, mixtures and composites thereof.

11. The assembly of claim 1 wherein the delivery tube contains up to 30 marker bodies.

12. The assembly of claim 1 wherein the delivery tube contains eight marker bodies.

13. The assembly of claim 1 wherein the sintered metallic marker is recognizably artificial when the marker body is remotely imaged by ultrasound or X-ray imaging.

14. The system of claim 1 wherein at least one of the marker bodies formed of bioabsorbable material is ultrasonically detectable.

15. The system of claim 7 wherein the sintered porous metallic material is selected from the group consisting of stainless steel, titanium, platinum, palladium and alloys thereof.

16. The system of claim 15 wherein the sintered porous metallic material is titanium.

17. The system of claim 15 wherein at least one marker body which is formed at least in part of sintered metallic material has a spherical shape.

18. The delivery system of claim 6 wherein the a plurality of marker bodies formed of bioabsorbable material are solid at a temperature of 40°

C.

19. The delivery system of claim 1 wherein the plurality of marker bodies formed of bioabsorbable material are ultrasonically detectable.

20. The delivery system of claim 6 wherein at least one marker body formed of binabsorbable material has a colorant incorporated therein.

21. The biopsy site marker of claim 1 wherein the bioabsorbable material is selected from the group consisting of gelatin or collagen.

22. The biopsy site marker of claim 21 wherein the collagen is renatured, cross-linked collagen.

23. The biopsy site market of claim 1 wherein the bioabsorbable material is dehydrated.

24. The system of claim 6 wherein the plurality of marker bodies formed of bioabsorbable material have a Bloom strength of at least 150.

25. The system of claim 6 wherein the plurality of marker bodies formed of bioabsorbabie material have a Bloom strength of not more than 300.

26. The system of claim 6 wherein the plurality of marker bodies formed of bioabsorbable material have a Bloom strength of about 200 to about 300.

27. The system of claim 6 wherein the plurality of marker bodies formed of bloabsorbable material have a Bloom strength of about 250 to about 300.

28. The assembly of claim 1 wherein the

at least one sintered metallic marker body is formed of a plurality of metallic particles.

29. The assembly of claim 28, wherein the sintered marker body has a length and diameter and the length is at least twice the diameter.

30. The assembly of claim 29, wherein said sintered marker measures approximately 1.5 mm in diameter and 3 mm in length.

31. The assembly of claim 28, wherein the sintered marker body is visible under multiple modalities.