U.S. patent application number 16/861622 was filed with the patent office on 2021-01-14 for device and method for use of photodynamic therapy.
This patent application is currently assigned to CranioVation, Inc.. The applicant listed for this patent is CranioVation, Inc.. Invention is credited to Vijay AGARWAL, Ranjith BABU, Jack RATCLIFFE.
Application Number | 20210008385 16/861622 |
Document ID | / |
Family ID | 1000005109423 |
Filed Date | 2021-01-14 |
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United States Patent
Application |
20210008385 |
Kind Code |
A1 |
AGARWAL; Vijay ; et
al. |
January 14, 2021 |
DEVICE AND METHOD FOR USE OF PHOTODYNAMIC THERAPY
Abstract
An apparatus including a light source provides for intracranial
treatment of a tissue region of a brain of a patient. The
intracranial treatment apparatus comprises an outer shaft having a
proximal end and a distal end for positioning within the tissue
region of the brain. The outer shaft defines a lumen extending
between the proximal end and the distal end of the outer shaft and
having at least one aperture adjacent the distal end of the outer
shaft. An inner light-delivery element having a distal end and a
proximal end is adapted to be operatively connected to the light
source. The light-delivery element is configured to be received
within the lumen and extend from the proximal end of the shaft to
adjacent the distal end of the shaft. The light-delivery element is
adapted to deliver light from the light source through the at least
one aperture of the outer shaft to the tissue region of the brain
in proximity to the distal end of the outer shaft.
Inventors: |
AGARWAL; Vijay; (Durham,
NC) ; BABU; Ranjith; (Durham, NC) ; RATCLIFFE;
Jack; (Wendell, NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CranioVation, Inc. |
Oakdale |
MN |
US |
|
|
Assignee: |
CranioVation, Inc.
Oakdale
MN
|
Family ID: |
1000005109423 |
Appl. No.: |
16/861622 |
Filed: |
April 29, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15109506 |
Jul 1, 2016 |
10675482 |
|
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PCT/US2015/010053 |
Jan 2, 2015 |
|
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16861622 |
|
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61923639 |
Jan 4, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/2272 20130101;
A61B 2018/2261 20130101; A61N 2005/0665 20130101; A61B 90/10
20160201; A61N 5/0601 20130101; A61K 41/0057 20130101; A61N
2005/0612 20130101; A61B 2018/2266 20130101; A61N 5/062 20130101;
A61B 2090/3966 20160201; A61B 90/39 20160201; A61B 2018/00321
20130101; A61B 2090/3954 20160201; A61N 2005/0651 20130101; A61N
2005/063 20130101 |
International
Class: |
A61N 5/06 20060101
A61N005/06; A61B 90/10 20060101 A61B090/10; A61B 90/00 20060101
A61B090/00; A61K 41/00 20060101 A61K041/00 |
Claims
1. An apparatus including a light source for intracranial treatment
of a tissue region of a brain of a patient, the intracranial
treatment apparatus comprising: an outer shaft having a proximal
end and a distal end for positioning within the tissue region of
the brain, the outer shaft defining a lumen extending between the
proximal end and the distal end of the outer shaft and having at
least one aperture adjacent the distal end of the outer shaft; and
an inner light-delivery element having a distal end and a proximal
end adapted to be operatively connected to the light source, the
light-delivery element configured to be received within the lumen
and extend from the proximal end of the shaft to adjacent the
distal end of the shaft, wherein the light-delivery element is
adapted to deliver light from the light source through the at least
one aperture of the outer shaft to the tissue region of the brain
in proximity to the distal end of the outer shaft.
2. The intracranial treatment apparatus as recited in claim 1,
wherein the outer shaft has a closed distal end so that the distal
end of the light-delivery element is contained within the outer
shaft.
3. The intracranial treatment apparatus as recited in claim 1,
wherein the outer shaft comprises a location marker adapted to be
located by one of magnetic resonance imaging, computerized x-ray
tomography, or combinations thereof.
4. The intracranial treatment apparatus as recited in claim 1,
wherein the light-delivery element comprises a fiber optic
cable.
5. The intracranial treatment apparatus as recited in claim 4,
wherein the light delivery element further comprises a diffuser
configured to be mounted to the distal end of the fiber optic
cable.
6. The intracranial treatment apparatus as recited in claim 5,
wherein the light delivery element further comprises a reflective
sphere disposed within the outer shaft distal to the diffuser.
7. The intracranial treatment apparatus as recited in claim 1,
wherein the outer shaft has a plurality of ports radially or
axially spaced along the outer shaft, and wherein the
light-delivery element comprises a plurality of independently
movable fiber optic cables, each of the plurality of fiber optic
cables extending from one of the ports and axially movable within
the lumen relative to the outer shaft between a first position
where the distal end of the fiber optic cable is adjacent the outer
shaft, and a second position where the distal end of the fiber
optic cable extends into the tissue region of the brain in
proximity to the outer shaft.
8. The active endoscopic device according to claim 1, further
comprising a light-emitting diode mounted on the distal end of each
of the plurality of fiber optic cables so as to effectively
irradiate a selected treatment site.
9. A method for intracranial treatment of a tissue region of a
brain of a patient, the intracranial treatment method comprising
the steps of: providing a device including a light source for
selectively irradiating tissue, the irradiating device comprising
an outer shaft having a proximal end and a distal end for
positioning within the tissue region of the brain, the outer shaft
defining a lumen extending between the proximal end and the distal
end of the outer shaft and having at least one aperture adjacent
the distal end of the outer shaft, and an inner light-delivery
element having a distal end and a proximal end configured to be
operatively connected to the light source, the light-delivery
element configured to be received within the lumen and extend from
the proximal end of the outer shaft to adjacent the distal end of
the outer shaft, positioning the distal end of the outer shaft
within close proximity to a selected site adjacent the tissue
region in the brain; and delivering light from the light source
through the light-delivery element and the at least one aperture of
the outer shaft to the tissue region of the brain in proximity to
the distal end of the outer shaft sufficient to kill a portion of
the tissue.
10. The intracranial treatment method as recited in claim 9,
wherein the outer shaft has a closed distal end so the
light-delivery element is contained within the lumen of the outer
shaft.
11. The intracranial treatment method as recited in claim 9,
further comprising the step of selectively determining a site
within the tissue of the brain for light delivery.
12. The intracranial treatment method as recited in claim 11,
wherein the outer shaft has a location marker, and wherein the
selectively determining step comprises locating the position of the
location marker within the brain by utilizing magnetic resonance
imaging, computerized x-ray tomography, or combinations
thereof.
13. The intracranial treatment method comprising as recited in
claim 11, wherein the selectively determined site is a tumor.
14. The intracranial treatment method as recited in claim 9,
further comprising the step of delivering photosensitive fluid
activated by radiation to the tissue region, and delivering
sufficient light to the tissue region in the presence of the
photosensitive fluid to kill the tissue.
15. The intracranial treatment method as recited in claim 9,
wherein the positioning step comprises introducing the outer shaft
through a percutaneous penetration in a skull of the patient.
16. The intracranial treatment method as recited in claim 9,
wherein the light-delivering element is a fiber optic cable.
17. The intracranial treatment method as recited in claim 9,
wherein the outer shaft has a plurality of ports radially or
axially spaced along the outer shaft, wherein the light-delivery
element comprises a plurality of independently movable fiber optic
cables, each of the plurality of fiber optic cables extending from
one of the ports and axially movable within the lumen relative to
the outer shaft between a first position where the distal end of
the fiber optic cable is adjacent the outer shaft, and a second
position where the distal end of the fiber optic cable extends into
the tissue region of the brain in proximity to the outer shaft, and
wherein the positioning step comprises moving the plurality of
fiber optic cables to the second position such that the distal end
of each of the plurality of fiber optic cables extends through the
port of the outer shaft and into the tissue region in proximity to
the outer shaft when the plurality of fiber optic cables is
advanced distally relative to the lumen.
Description
BACKGROUND
[0001] A device and method is shown and described for use in
irradiating or otherwise administering light to a location within
the body of a patient and, more particularly, a device and method
for the use of photodynamic therapy for the therapeutic treatment
of tissue in the brain or other part of the body of the patient,
including tumors, such as malignant brain neoplasms.
[0002] There are a variety of medical procedures that require light
or irradiated energy to be administered to a patient within the
body. Photodynamic therapy (PDT) is a form of treatment that relies
on exposing an area of tissue to a selected wavelength of
activating radiation. PDT uses non-toxic, photosensitive compounds
that accumulate selectively in targeted tissue. The photosensitive
compounds become toxic when exposed to light at selected
wavelengths. This leads to chemical destruction of any tissues
which have selectively taken up the photosensitizer and have been
selectively exposed to light.
[0003] One application of PDT is in oncology for the destruction of
malignant cell masses in the body. PDT has been used effectively in
the treatment of a variety of human tumors and precancerous
conditions, including basal and squamous cells, skin cancers, lung
cancer, breast cancer, metastatic to skin, brain tumors, and head
and neck, stomach, and the female genital tract malignancies. PDT
has also been used to treat the cancers and precancerous conditions
of the esophagus, such as Barrett's esophagus. In the latter
application, a photosensitizer, such as Photophrin, is first
administered. A 630 nm light from a KTP/dye laser, a diode laser,
or an argon-pumped dye-laser is delivered using a PDT balloon
having a reflective inner surface. The PDT balloon includes an
internal cylindrical diffuser and has several windows for
illuminating the treatment area.
[0004] Therapeutic use of PDT in the brain has been minimal
Therefore, evidence for the efficacy and the safety of PDT for use
in the brain is limited in quality and quantity. However, the
introduction of probes or similar devices into the brain is common
in many surgical procedures. The probes used for intracranial
penetration are typically fabricated so that their introduction
into the brain is as minimally traumatic as possible. During
typical implantation, a surgeon feeds the probe into the brain
through an aperture in the skull. Probes inserted into the brain
typically include ports for drug delivery or paired contacts
positioned at specific points or regions in the brain. The contacts
are electrical, chemical, electrochemical, temperature or pressure
contacts, which enable the observation and analysis of the brain
state or provide stimulation. In addition, neurosurgeons use
photosensitizers when resecting infiltrative tumors. The
photosensitizers fluoresce when light of a certain wavelength is
shined on the cells allowing for rough identification of the tumor
margins.
[0005] For the foregoing reasons, there is a need for a new device
and method for the use of photodynamic therapy (PDT) for the
therapeutic treatment of tissue in the brain of a patient. The new
device and method should ideally include a probe or similar device
familiar to neurosurgeons to deliver PDT for the treatment of the
brain tissue, including tumors such as malignant brain neoplasms.
In one aspect, the new device and method for PDT is useful and
effective for other parts of the body in addition to the brain.
SUMMARY
[0006] An apparatus for use in photodynamic therapy is described,
in one embodiment, for intracranial treatment of a tissue region of
a brain of a patient. The intracranial treatment apparatus
comprises an outer shaft having a proximal end and a distal end for
positioning within the tissue region of the brain. The outer shaft
defines a lumen extending between the proximal end and the distal
end of the outer shaft and having at least one aperture adjacent
the distal end of the outer shaft. An inner light-delivery element
has a distal end and a proximal end adapted to be operatively
connected to a light source. The light-delivery element is
configured to be received within the lumen and extend from the
proximal end of the shaft to adjacent the distal end of the shaft.
The light-delivery element is adapted to deliver light from the
light source through the at least one aperture of the outer shaft
to the tissue region of the brain in proximity to the distal end of
the outer shaft.
[0007] In one aspect, the outer shaft has a plurality of ports
radially or axially spaced along the outer shaft. In this
embodiment, the light-delivery element comprises a plurality of
independently movable fiber optic cables, each of the plurality of
fiber optic cables extending from one of the ports and axially
movable within the lumen relative to the outer shaft between a
first position where the distal end of the fiber optic cable is
adjacent the outer shaft, and a second position where the distal
end of the fiber optic cable extends into the tissue region of the
brain in proximity to the outer shaft.
[0008] A method for intracranial treatment of a tissue region of a
brain of a patient is also described. The intracranial treatment
method comprises the steps of providing a device including a light
source for selectively irradiating tissue. The irradiating device
comprises an outer shaft having a proximal end and a distal end for
positioning within the tissue region of the brain. The outer shaft
defines a lumen extending between the proximal end and the distal
end of the outer shaft and having at least one aperture adjacent
the distal end of the outer shaft. An inner light-delivery element
has a distal end and a proximal end configured to be operatively
connected to the light source. The light-delivery element is
configured to be received within the lumen and extend from the
proximal end of the outer shaft to adjacent the distal end of the
outer shaft. The distal end of the outer shaft is positioned within
close proximity to a selected site adjacent the tissue region in
the brain. Light is delivered from the light source through the
light-delivery element and the at least one aperture of the outer
shaft to the tissue region of the brain in proximity to the distal
end of the outer shaft sufficient to kill a portion of the
tissue.
[0009] In a further aspect of the method, the outer shaft has a
plurality of ports radially or axially spaced along the outer
shaft. The light-delivery element comprises a plurality of
independently movable fiber optic cables, each of the plurality of
fiber optic cables extending from one of the ports and axially
movable within the lumen relative to the outer shaft between a
first position where the distal end of the fiber optic cable is
adjacent the outer shaft, and a second position where the distal
end of the fiber optic cable extends into the tissue region of the
brain in proximity to the outer shaft. The positioning step
comprises moving the plurality of fiber optic cables to the second
position such that the distal end of each of the plurality of fiber
optic cables extends through the port of the outer shaft and into
the tissue region in proximity to the outer shaft when the
plurality of fiber optic cables is advanced distally relative to
the lumen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a more complete understanding of the present invention,
reference should now be had to the embodiments shown in the
accompanying drawings and described below. In the drawings:
[0011] FIG. 1 is a perspective view of an embodiment of a device
for providing photodynamic therapy to the brain of a patient.
[0012] FIG. 2 is exploded perspective of the photodynamic therapy
device as shown in FIG. 1.
[0013] FIG. 3 is a longitudinal cross-section view of the
photodynamic therapy device as shown in FIG. 1.
[0014] FIG. 4 is a close-up view of an embodiment of tip of a wand
for use with the photodynamic therapy device as shown in FIG.
1.
[0015] FIG. 5 is an exploded perspective view of the tip of the
wand as shown in FIG. 4.
[0016] FIG. 6 is a longitudinal cross-section view of the tip of
the wand as shown in FIG. 4.
[0017] FIG. 7 is front perspective view of another embodiment of a
device for providing photodynamic therapy to the brain of a
patient.
[0018] FIG. 8 is a rear perspective view of the photodynamic
therapy device as shown in FIG. 7.
[0019] FIG. 9 is an exploded perspective view of the photodynamic
therapy device as shown in FIGS. 7 and 8.
[0020] FIG. 10 is a longitudinal cross-section of the photodynamic
therapy device as shown in FIGS. 7 and 8.
[0021] FIG. 11 is a close-up perspective view of an embodiment of
tip of a wand for use with the photodynamic therapy device as shown
in FIGS. 7 and 8 and showing with light delivering elements in a
first position.
[0022] FIG. 12 is a close-up perspective view of the tip of the
wand as shown in FIG. 11 with light delivering elements in a second
position.
DESCRIPTION
[0023] Certain terminology is used herein for convenience only and
is not to be taken as a limitation on the invention. For example,
words such as "upper," "lower," "left," "right," "horizontal,"
"vertical," "upward," and "downward" merely describe the
configuration shown in the FIGS. Indeed, the components may be
oriented in any direction and the terminology, therefore, should be
understood as encompassing such variations unless specified
otherwise.
[0024] As used herein, the term "light", "light irradiation", or
"irradiation" refers to light of wavelengths from about 300 nm to
about 1200 nm. This includes UV, visible and infrared light. The
PDT device can be used with any wavelength of light. The choice of
wavelength will be determined by the intended application, namely
being selected to match the activation wavelength of the
photosensitive drug or the wavelength used for irradiation when a
photo-activated compound is not employed.
[0025] Referring now to the FIGS. 1-3, wherein like reference
numerals designate corresponding or similar elements throughout the
several views, an embodiment of a device for selectively applying
photodynamic therapy to structures in the brain is shown in FIGS.
1-3 and generally designated at 20. The PDT device 20 comprises a
housing 22 that accommodates a light-generating apparatus,
including a light source 24 and a power source 26 to power the
light source. A tubular wand 28 extends from a distal end 23 of the
housing 22. A embodiment of a method of photodynamic therapy
comprises positioning the wand 28 of the PDT device 20 adjacent to
the target site so that the wand is brought into at least partial
contact, or close proximity, with a tissue structure within the
patient's brain, such as tumor tissue. Light is then delivered via
the wand 28 for treating at least a portion of the tissue structure
in situ. The PDT device 20 is particularly useful for therapeutic
treatment of benign or malignant tumors in the brain.
[0026] The housing 22 may be formed from a plastic material that is
molded into a suitable shape for handling by a surgeon. As shown in
FIGS. 2 and 3, the housing 22 defines an inner cavity 30 for
receiving the light source 24 and the power supply 26 and
associated electrical connections (not shown). In this embodiment
of the PDT device 20, a proximal handle 32 is integral to the
housing 22. The handle 32 is sized to be grasped and manipulated by
the surgeon during a surgical procedure. It is understood that the
housing 22 of the PDT device 20 may be various sizes and shapes,
depending upon the context of use. As best seen in FIG. 1, the
proximal end 25 of the housing 22 includes an actuating button 34
for selectively powering the light source 24. An indicator light 36
shows when the light source 24 is powered. The power source 26
provides a sufficient voltage to establish the requisite conditions
for light delivery to the tissue. In the embodiment shown, the
power supply 26 is an onboard battery, for example, a rechargeable
11.1 V lithium ion battery.
[0027] The tubular wand 28 comprises an outer shaft 38 defining a
lumen extending from the proximal end 39 of the shaft to the distal
end 42 of the shaft 38. A fiber optic cable 40 is disposed within
the lumen and operates to transfer light from the light source 24
to distal end 29 of the wand. The light is emitted from the distal
end 29 of the wand 28 for exposing a tissue region in the brain of
a patient. The outer shaft 38 is a thin elongated tubular element
with a smooth outer surface in order to minimize the amount of
brain tissue contacted and to minimize damage to contacted brain
tissue. The outer shaft 38 will typically have a diameter of at
least about 0.6 mm and frequently in the range from about mm 1 to
about 10 mm. In one embodiment, the diameter of the outer shaft 38
is preferably between and 1.5 millimeters, most preferably about
1.0 millimeter. The outer shaft 38 generally has a length dimension
which permits the shaft 38 to be introduced through a burr hole in
the cranium or through a conventional transoral or transphenoidal
route. Thus, the outer shaft 38 will typically have a length of at
least about 5 cm for open surgical procedures and at least about 10
cm, or more typically about 20 cm or longer for endoscopic
procedures.
[0028] The outer shaft 38 is preferably rigid for percutaneous,
transluminal or direct delivery to the brain in either open
procedures or port access type procedures. The outer shaft 38 may
be formed from polyurethane, silicone, polyimede, or other
biocompatible material. Alternatively, the shaft may comprise a
metal, which is selected from the group consisting of tungsten,
stainless steel alloys, platinum or its alloys, titanium or its
alloys, molybdenum or its alloys, and nickel or its alloys.
Alternatively, the outer shaft 38 may be flexible, being combined
with a generally rigid internal tube (not shown) for mechanical
support. Flexible shafts may also be combined with pull wires for
guiding the outer shaft 38 to a target tissue site, shape memory
actuators, and other known mechanisms for effecting selective
deflection of the outer shaft to facilitate positioning of a distal
end 39 of the shaft 38. The outer shaft 38 may also include
elements for providing a location marker for determining the
precise position of the wand 28 within the brain of a patient.
[0029] The fiber optic cable 40 may be a fiber optic bundle or
liquid light guide. For convenience, these elements hereinafter are
referred to collectively as a fiber optic cable 40. The fiber optic
cable 40 extends from the proximal end 39 to the distal end 42 of
the outer shaft 38. The proximal end of the fiber optic cable 40 is
operably connected to the light source 24 for delivering light to a
tissue region adjacent the distal end 42 of the shaft 38. The fiber
optic cable 40 can be of any diameter so long as the fiber optic
cable can be inserted into the lumen of the outer shaft 38. The
preferred diameter of the fiber optic cable is from about 50
microns to about 1000 microns and preferably about 400 microns. The
choice of the diameter will depend on the brightness of the light
source 24 and the optical power output required from the tip of the
fiber optic cable 40.
[0030] Referring to FIGS. 4-6, the distal end 29 of the wand 28
comprises a rigid elongated end cap 44 coupled to the distal end 42
of the outer shaft 38. The end cap 44 is generally cylindrical and
extends from the distal end 42 of the shaft 38 a distance of about
1 mm to about 20 mm. The end cap 44 tapers to a point 45 at a
closed distal end. The end cap houses a diffusion tip or diffuser
46 and a ball bearing 48. As used herein, a diffuser or diffusion
tip, is defined as an element that can be attached to the end of a
fiber optic cable, or a structure that can be formed at the end of
the fiber optic cable, that provides a means for diffusing
(scattering) the light being transmitted through the fiber optic
cable so that it radiates outward from the fiber. In the embodiment
shown in the FIGS., the diffuser 46 is a generally hemispherical
reflective shell that mounts to the distal end of the fiber optic
cable 40 which is received within the shell. Light transmitted and
emitting from the fiber optic cable 40 is diffused by the diffuser
46 for providing an even radial distribution of the light. A
diffuse source of radiation can expose a greater area of tissue to
activation energy. The outer surface of the ball bearing 48 is
reflective to further diffuse the transmitted light.
[0031] One or more apertures 50 are provided along the surface of
the end cap 44. For example, the embodiment shown in FIGS. 4-6
shows a pair of opposed axial apertures 50 circumferentially spaced
on the body of the end cap 44. During PDT, light is delivered to
the surrounding brain tissue region through the apertures 45. The
end cap 44 may also contain a right angle prism 51 to provide for
re-direction of light through the apertures 45. The fiber optic
probe 40 is arranged to the right angle prism 51 so that the light
exits from the apertures 45 in the end cap 44.
[0032] An optional piezoelectric ceramic member 52 may also be
housed within the end cap 44. The piezoelectric member 52 is
coupled to wire connectors 54 that extend to the proximal end of
outer shaft 38 where they are suitably connected to the power
supply 26. A frequency level adjustment knob 66 on the housing 22
enables adjustment of the intensity of the piezoelectric member 52
allowing for variable intensity application of a desired
frequency.
[0033] Referring now to the FIGS. 7-10, another embodiment of a
device for selectively applying photodynamic therapy to structures
in the brain is shown and generally designated at 60. The PDT
device 60 comprises a housing 62 that accommodates a light source
64. The housing provides a suitable interface for receiving an
electrical connecting cable 66 from a power source (not shown) for
providing power to the light source 64. A tubular wand 66 extends
from a distal end 63 of the housing 62 which tapers to conform to a
proximal end 67 of the wand 66. As shown in FIGS. 9 and 10, the
housing 62 defines an inner cavity 70 that houses the light source
64 and associated electrical connections (not shown). The housing
62 may be formed from a plastic material that is molded into a
suitable shape for handling by a surgeon. The housing 62 of the PDT
device 60 is sized to be grasped and manipulated by the surgeon
during a surgical procedure.
[0034] The tubular wand 68 comprises an elongated outer shaft 72
defining a lumen extending from a proximal end 73 of the shaft 72
to a distal end 74 of the shaft 72. A plurality of fiber optic
cables 76 are disposed within the lumen and operate to transfer
light from the light source 64. The diameter of the outer shaft is
preferably in the range from about 0.08 mm to about 1.0 mm, and
more preferably in the range of from about 0.05 mm to about 0.4 mm.
The outer shaft 72 extends about 1 cm to about 20 cm from the
distal end 63 of the housing 62. In this embodiment of the PDT
device 60, the outer shaft 72 may assume a wide variety of
configurations, with the primary purpose being to mechanically
support a plurality of light-delivering elements and permit the
surgeon to manipulate the light delivery elements from the proximal
end of the housing 62. The shaft may be formed from the group
including stainless steel, copper-based alloys, titanium or its
alloys, and nickel-based alloys.
[0035] Each of the fiber optic cables 76 has a proximal end and a
distal end. The proximal portion of outer shaft 72 includes a
multi-fitment (not shown) which provides for interconnections
between the proximal ends of the fiber optic cables 76 and the
light source 64 within the housing 62 adjacent to the fitment. In
one embodiment, the fiber optic cables 76 are independent from one
another and deliver light separately from the light source 64.
Alternatively, the fiber optic cables 76 may be connected together
at their the proximal ends to form a single fiber that couples to
the light source 64. It is understood that the PDT device 60 is not
limited to isolated fiber optic cables or even to a plurality of
fiber optic cables. For example, the plurality of fiber optic
cables 76 may be connected to a single lead that extends through
the outer shaft 72 to the light source 64.
[0036] Referring to FIGS. 11-13, the outer shaft 72 defines a
plurality of axially and circumferentially spaced ports 78 adjacent
the distal end 74 of the shaft 72. The posts 78 open into the lumen
and are each configured for passing one of the plurality of fiber
optic cables 76 running axially through the lumen. Each of the
fiber optic cables 76 has a distal end which passes from the lumen
via a corresponding port 78 into the tissue region beyond the
surface of the outer shaft 72.
[0037] A light-emitting diode (LED) 80 is connected to the distal
end of each of the fiber optic cables 76 external to the outer
shaft 72. In this arrangement, the PDT device 60 comprises a
distributed array of LED's 80 spaced axially and circumferentially
around the distal end 74 of the outer shaft 72. LED's 80 emit a
diverging beam of light without the need for a diffuser. In
addition, while the LED's 80 are depicted as short cylinders, the
LED's 80 can have any suitable shape, including spherical, twizzle
shapes for needle-like cutting, spring shapes or other twisted
metal shapes, and the like.
[0038] The fiber optic cables 76 have a length greater than the
shaft length and are configured for axial movement relative to the
shaft. It is understood that the assembly can include many fiber
optic cables 76 of different lengths and having different
arrangements of apertures or ports to selectively provide for
treatment of specific desired targeted tissue regions in the brain.
Optic exit site and depth of penetration can be determined
preoperatively via 3-dimensional imaging planning software. The
area of the tissue treatment can vary widely, with particular areas
and geometries being selected for specific applications. This
allows for optimal fiber optic penetration into, for example, a
tumor, which also optimizes the amount of light that is delivered
to the tumor.
[0039] In use, the wand 28, 68 of the PDT device 20, 60 is
introduced through a small opening, e.g., a burr hole, or other
percutaneous penetration in the patient's cranium, or through
natural openings in the patient's head, such as transoral or
transphenoidal procedures. The wand is advanced intraluminally and
guided to a target site within the brain in a conventional manner,
i.e., percutaneously, transluminally or using other minimally
invasive or traditional open surgery techniques. The chosen
technique may be performed in conjunction with an instrument
guiding technology for guiding the PDT device 20, 60 to the target
site within the brain. Accordingly, the target site may be charted
with a variety of imaging techniques, such as computerized
tomography (CT) scanning, magnetic resonance imaging (MRI),
ultrasound, angiography, radionucleotide imaging,
electroencephalography (EEG) and the like. In conjunction with one
of these imaging procedures, typically CT or MRI, the user may also
use compatible stereotactic systems for guiding the instrument to
the target site. In standard stereotactic systems, a frame, e.g., a
Leksell, Todd-Wells or Guiot frame, fixes the head of the patient
to the image. These frames, combined with radiological landmarks
and a brain atlas, provide anatomical localization to within +-1
mm. Alternatively, imaged guided frameless stereotactic systems
that utilize modern imaging, computer software and a locating
device, may be employed. For use with these guidance and locating
techniques, the wand 28, 68 may have a location marker comprising
material which contains a mobile phase suitable for MRI imaging by
commercial machines, and which is sufficiently X-Ray-opaque for
adequate imaging on CT or X-ray.
[0040] Once the distal end of the wand 28, 68 is positioned
adjacent to, or in contact with, the affected tissue at the target
site, light is delivered via the fiber optic cables 40, 76. A
photosensitive compound, such as 5-ALA or Photophrin, is then
delivered through the lumen of the shaft or through another
catheter to the tissue region. Light is then applied through the
apertures 45 in the end cap 44 or from the LED's 80 directly at the
desired site in the presence of the photosensitive compound to
treat the tissue structure. The light is sufficient for the
therapeutic treatment of intracranial tumors while minimizing the
collateral damage to surrounding tissue or nerves within the brain
of the patient. The power sources can be utilized to illuminate
fiber probes or the LED's which emit light at wavelengths of either
405 nm wavelength, for diagnostic purposes, or 635 nm, or
therapeutic purposes. It is understood that the delivered light may
be at other wavelengths, including within or outside the range of
405 nm to 635 nm. The application of light for appropriate time
intervals affects or otherwise modifies the target tissue. The
light is sufficient to activate the photosensitive compound, which
results in death of the tumor tissue. The tissue volume over which
the light is delivered may be precisely controlled.
[0041] When using the PDT device 60 comprising the plurality of
LED's 80, each corresponding fiber optic cable 76 is preferably
introduced to the brain through the wand 68 such that a particular
LED 80 penetrates to a desired portion of the brain tissue. Such an
arrangement allows for inserting the wand 68 through the
intervening brain tissue, precisely locating the wand 68 relative
to a specific tissue region and then advancing the plurality of
LED's via the fiber optic cables 76 for positioning the LED's at a
predetermined tissue region for treating the tissue region.
[0042] The device for selectively applying photodynamic therapy to
structures in the brain has many advantages, including providing a
minimally invasive method for delivering light for PDT treatment of
tumors in the brain. Placement of means for light delivery at the
distal end of the device to brings the light source directly to the
desired site providing light irradiation to a defined, targeted
area of tissue. The result is precise intracranial treatment within
tissue in the brain of a patient. The device and method provide the
surgeon the ability to treat malignant brain tumors, even those
that are in difficult to reach locations, without a large open
surgery. The device provides the potential to deliver light
therapy, in a diagnostic or therapeutic fashion, to brain tumors
via a very small opening the skull, including for those lesions
deemed dangerous to operate on.
[0043] Although the device and method for PDT has been shown and
described in considerable detail with respect to only a few
exemplary embodiments thereof, it should be understood by those
skilled in the art that we do not intend to limit the device and
method to the embodiments since various modifications, omissions
and additions may be made to the disclosed embodiments without
materially departing from the novel teachings and advantages,
particularly in light of the foregoing teachings. For example,
therapeutic use of PDT in the brain is described, but it is
understood that PDT for any other part of the body is contemplated.
In addition, the choice of materials used in each of the components
of the devices described herein, and in particular the overall
geometry of the devices, can be specifically tailored to provide
the desired properties for a given treatment indication.
Accordingly, we intend to cover all such modifications, omission,
additions and equivalents as may be included within the spirit and
scope of the following claims. In the claims, means-plus-function
clauses are intended to cover the structures described herein as
performing the recited function and not only structural equivalents
but also equivalent structures. Thus, although a nail and a screw
may not be structural equivalents in that a nail employs a
cylindrical surface to secure wooden parts together, whereas a
screw employs a helical surface, in the environment of fastening
wooden parts, a nail and a screw may be equivalent structures.
* * * * *