METHOD FOR IDENTIFYING A SITE FOR SURGICAL REMOVAL

Abstract

A method for marking a biopsy site after a biopsy has been performed includes the steps of placing a marker in the form of a semi-permeable membrane at the biopsy site so that the marker can be found at a later time, inserting a needle into the marker at the later time which is preferably immediately before a planned surgical resection of the biopsy site, and injecting a dye directly into the marker to color the marker. The semi-permeable qualities of the marker facilitate the slow egress of dye into tissue that is immediately adjacent the marker, enlarging the footprint of the marker. The semi-permeable membrane includes a high percentage of water after reaching osmotic equilibrium, rendering the marker highly visible under ultrasound imaging. The semi-permeable membrane may take the form of a fully or partially dehydrated hydrogel.

Claims

1. A biopsy site marker comprising: a body defining an outer perimeter of the marker, the body including hydrogel, the hydrogel being configured to transition from a dehydrated state to a hydrated state, the hydrogel being configured further to expand in size when transitioning from the dehydrated state to the hydrated state, the hydrogel including a radiation emitting material, the radiation emitting material being configured to permit detection of the marker using a gamma camera.

2. The marker of claim 1, further comprising a localization element including a wire, a portion of the localization element being disposed within the body.

3. The marker of claim 2, the localization element being configured to detection under x-ray visualization.

4. The marker of claim 1, the hydrogel further including a plurality of nanoparticles, the nanoparticles being configured to emit electromagnetic radiation.

5. The marker of claim 1, the hydrogel further including a radiopaque contrast agent.

6. The marker of claim 1, the hydrogel further including a medical dye.

7. The marker of claim 6, the medical dye including one or more of methylene blue, toluene blue, gentian violet, methyl violet, dichlorophenolindophenol, fluorescein, Prussian blue, Egyptian blue, Han purple, potassium ferrocyanide, potassium ferricyanide, and phenothiazine.

8. The marker of claim 1, the hydrogel being configured to form a semi-permeable membrane.

9. A system for locating a biopsy site, the system comprising: (a) a marker, the marker including a hydrogel body, the hydrogel body being configured to transition from a dehydrated state to a hydrated state, the hydrogel being configured further to expand in size when transitioning from the dehydrated state to the hydrated state, the hydrogel body including a radiation emitting compound; and (b) a gamma camera, the gamma camera being configured to detect radiation emitted from the radiation emitting compound to locate the position of the marker within tissue.

10. The system of claim 9, further comprising a localization element including a wire, a portion of the localization element being disposed within the hydrogel body.

11. The marker of claim 10, the localization element being configured to detection under x-ray visualization.

12. The marker of claim 9, the hydrogel body further including a plurality of nanoparticles, the nanoparticles being configured to emit electromagnetic radiation.

13. The marker of claim 9, the hydrogel body further including a radiopaque contrast agent.

14. The marker of claim 9, the hydrogel body further including a medical dye.

15. The marker of claim 14, the medical dye including one or more of methylene blue, toluene blue, gentian violet, methyl violet, dichlorophenolindophenol, fluorescein, Prussian blue, Egyptian blue, Han purple, potassium ferrocyanide, potassium ferricyanide, and phenothiazine.

16. The marker of claim 9, the hydrogel being configured to form a semi-permeable membrane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed disclosure, taken in connection with the accompanying drawings, in which:

[0027] FIG. 1 depicts a semi-permeable membrane when in its fully dehydrated condition and prior to the introduction of any dye thereinto;

[0028] FIG. 2 depicts the semi-permeable membrane of FIG. 1 when in a hydrated condition and after a dye has been injected thereinto; and

[0029] FIG. 3 depicts the semi-permeable membrane in a hydrated condition after dye has been injected thereinto where the semi-permeable membrane has been in a patient's body for a time sufficient for some of the dye to have spread from the semi-permeable membrane into surrounding tissue of the patient's body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0030] The novel method for marking a biopsy site after a biopsy has been performed includes the step of placing a marker in the form of a semi-permeable membrane in a fully dehydrated state at the biopsy site so that the marker can be found at a later time under imaging guidance means such as ultrasound, CT, X-ray, MRI, PET, fluoroscopic imaging, radiation emitting compounds that are detected with a gamma camera, and the like.

[0031] A partially dehydrated semi-permeable membrane may also be used instead of a fully dehydrated semi-permeable membrane.

[0032] The preferred embodiment of this invention employs a hydrogel as the preferred semi-permeable membrane. The semi-permeable membrane includes a high percentage of water after reaching osmotic equilibrium, rendering the marker highly visible under ultrasound imaging.

[0033] In a first embodiment, a needle is inserted into the marker and a medical dye is injected into the marker at the time of the biopsy procedure.

[0034] In a second embodiment, no medical dye is inserted into the marker at the time of the biopsy procedure and the marker is found at a later date using the aforesaid conventional imaging guidance means. The dye is then injected into the marker immediately prior to a surgical resection.

[0035] The needle is used in both embodiments to inject a medical dye such as methylene blue, toluene blue, gentian violet, methyl violet, dichlorophenolindophenol, fluorescein, Prussian blue, Egyptian blue, Han purple, potassium ferrocyanide, potassium ferricyanide, phenothiazine, or the like directly into the marker. The dye colors the marker to facilitate identification of the marker at the time of a surgical removal of a lesion at said biopsy site.

[0036] FIG. 1 depicts semi-permeable membrane 10 when in its fully dehydrated condition and prior to the introduction of any dye thereinto.

[0037] FIG. 2 depicts semi-permeable membrane 10 when in a hydrated condition and after dye 12, represented by cross-hatching, has been injected thereinto.

[0038] FIG. 3 depicts semi-permeable membrane 10 in a hydrated condition after dye 12 has been injected thereinto and where semi-permeable membrane 10 has been in a patient's body for a time sufficient for some of dye 12 to have spread from semi-permeable membrane 10 into surrounding tissue of the patient's body.

[0039] The semi-permeable quality of the marker facilitates the egress of dye into the immediate surrounding tissue, identifying not just the marker but also the tissue immediately adjacent the marker, thereby enlarging the footprint of the marker and thus facilitating identification of the biopsy site.

[0040] The marker may also be injected with therapeutic agents including chemotherapy drugs, antibiotics and radioactive material for the purpose of high drug, antibiotic, and radiation concentration in a very localized area. The dye or drugs remains localized based on the osmotic properties of semi-permeable membranes. Said osmotic properties have no effect on radiation.

[0041] The injection may also be performed through a standard wire localization needle. A localization wire is then advanced into the marker to further enhance localization.

[0042] The methylene blue, tolulene blue, or other medical-grade dye may also be mixed with a radioopaque contrast agent if a mammogram or X-rays will be used to localize a wire position. When using a mammogram to check the wire position, the contrast agent will facilitate the determination as to whether or not the marker has been found.

[0043] If a mammogram/X-ray is used to find the wire in a case where a radioopaque contrast agent but no medical dye was injected into the marker at the time the wire localization was performed, such medical-grade dye or therapeutic substance, or both, can be injected into the marker at that time. The marker is found under ultrasound first. The dye or therapeutic substance, or both, is then injected into the marker to make it more visible on mammogram, visual identification, and other imaging modalities.

[0044] A dye or therapeutic substance can also be injected into tissue in the immediate vicinity of the marker and osmotic diffusion will result in absorption of such dye or therapeutic substance by said marker upon contact.

[0045] Compounds having utility as marking agents include, for example, fludeoxyglucose (.sup.18F) or fluorodeoxyglucose (.sup.18F), commonly abbreviated .sup.18F-FDG or FDG. This compound is a radiopharmaceutical that can be used in conjunction with fluorescent material in a form of nano particles, such as plasmonic fluorescent quantum dots, which are injected into the hydrogel to facilitate locating tumor cells under different wavelength light sources, such as UV light, during surgery.

[0046] These compounds may serve as imaging agents or marking agents, depending upon the molecule. The novel marker may also be injected with nanoparticles that could function as imaging or marking agents or nanoparticles that could yield a high dose local treatment of a tumor by continuously diffusing out of the hydrogel at a slow rate.

[0047] It will thus be seen that the objects set forth above, and those made apparent from the foregoing disclosure, are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matters contained in the foregoing disclosure or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

[0048] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention that, as a matter of language, might be said to fall therebetween.