U.S. patent application number 13/831328 was filed with the patent office on 2013-08-08 for brachytherapy apparatus and method for use with minimally invasive surgeries of the lung.
This patent application is currently assigned to XOFT, INC.. The applicant listed for this patent is XOFT, INC.. Invention is credited to Mark P. Carol, James E. Jervis, Paul A. Lovoi.
Application Number | 20130204071 13/831328 |
Document ID | / |
Family ID | 40583720 |
Filed Date | 2013-08-08 |
United States Patent
Application |
20130204071 |
Kind Code |
A1 |
Carol; Mark P. ; et
al. |
August 8, 2013 |
BRACHYTHERAPY APPARATUS AND METHOD FOR USE WITH MINIMALLY INVASIVE
SURGERIES OF THE LUNG
Abstract
Brachytherapy treatment of a patient's lung tissue following
resection is effected using a balloon applicator which is inserted,
normally through the same opening used for the surgery, through the
chest wall and into the cavity. The lung and chest openings are
closed around the applicator and generally sealed around the
applicator. A suction port is provided, in a suction circuit of the
applicator, to withdraw fluid from the pleural cavity, at intervals
as needed, to assure that the lung can be inflated. Different
embodiments of suction circuits are disclosed. A bronchial
applicator and method are also disclosed.
Inventors: |
Carol; Mark P.; (Burlingame,
CA) ; Jervis; James E.; (Atherton, CA) ;
Lovoi; Paul A.; (Saratoga, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
XOFT, INC.; |
Sunnyvale |
CA |
US |
|
|
Assignee: |
XOFT, INC.
Sunnyvale
CA
|
Family ID: |
40583720 |
Appl. No.: |
13/831328 |
Filed: |
March 14, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11978147 |
Oct 26, 2007 |
8409070 |
|
|
13831328 |
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Current U.S.
Class: |
600/3 |
Current CPC
Class: |
A61B 1/018 20130101;
A61B 1/00094 20130101; A61N 5/1002 20130101; A61B 1/2676 20130101;
A61N 5/1015 20130101; A61M 1/0023 20130101; A61B 1/00082
20130101 |
Class at
Publication: |
600/3 |
International
Class: |
A61N 5/10 20060101
A61N005/10; A61B 1/018 20060101 A61B001/018; A61B 1/00 20060101
A61B001/00; A61M 1/00 20060101 A61M001/00; A61B 1/267 20060101
A61B001/267 |
Claims
1. An applicator adapted for brachytherapy treatment in a human
lung of a patient, comprising: a shaft having a proximal end and a
distal end and defining an elongated internal channel; an
inflatable balloon secured to the distal end of the shaft; a
catheter carrying a source of ionizing radiation at or near the
distal end of the catheter; the shaft elongated internal channel
receiving the catheter and radiation source; a hub disposed at the
proximal end of the shaft through which the catheter is inserted;
the hub including an inflation port for inflating the balloon
through the shaft; a suction sleeve having a proximal end and a
distal end; the suction sleeve being disposed coaxially about the
shaft, being constructed and arranged for sliding motion on the
shaft between withdrawn and advanced positions thereof, and
defining a suction channel extending in a direction between
proximal and distal ends thereof and about the shaft; a suction
port at and in communication with the suction sleeve; the suction
sleeve having the distal end thereof open for communication with a
body cavity in the advanced position thereof.
2. The applicator of claim 1 wherein the suction sleeve is
tubular.
3. The applicator of claim 2 wherein the distal end of the tubular
suction sleeve is open to form an annular coupling port to the body
cavity.
4. The applicator of claim 1 wherein the suction sleeve has a fluid
tight seal at the proximal end thereof.
5. The applicator of claim 4 wherein the proximal end of the
suction sleeve is enlarged and the seal comprises an o-ring seal
disposed at the enlarged end.
6. The applicator of claim 4 wherein the suction port of the
suction sleeve extends radially of the suction sleeve.
7. The applicator of claim 1 wherein the shaft extends across the
full diameter of the balloon.
8. The applicator of claim 1 wherein the suction sleeve is disposed
proximal to the inflatable balloon, and the shaft has a distal most
end that is in contact with the balloon.
9. The applicator of claim 1 including a knob at the proximal end
of the suction sleeve, and wherein the shaft is attached at opposed
sides of the balloon.
10. An applicator adapted for brachytherapy treatment in a human
lung, comprising: a shaft with an inflatable balloon secured to its
distal end, the shaft defining an internal channel adapted to
receive a catheter carrying a source of ionizing radiation near the
distal end of the catheter; the shaft including, at a proximal end
thereof, a hub through which the catheter can be inserted, and the
hub including provision for inflating the balloon through the
shaft; a suction port positioned to communicate via a suction
circuit with the pleural cavity of the patient to drain or evacuate
fluid; and the suction circuit including a slidable sleeve having a
distal end thereof forming the suction port, adjustable as to axial
position about and along the shaft, with the suction port
positionable at a body cavity, and an evacuation port positioned on
the sleeve to be exterior of the body cavity.
11. The applicator of claim 10 wherein the distal end of the
suction sleeve is open to form an annular coupling port to the body
cavity.
12. The applicator of claim 10 wherein the suction sleeve has a
fluid tight seal at the proximal end thereof, and a knob for
manipulating the sleeve.
13. The applicator of claim 10 wherein the shaft extends across the
full diameter of the balloon.
14. The applicator of claim 10 wherein the suction sleeve is
disposed proximal to the inflatable balloon, and the shaft has a
distal most end that is in contact with the balloon.
15. The applicator of claim 10 including a knob at the proximal end
of the suction sleeve, and wherein the shaft is attached at opposed
sides of the balloon.
16. A method for brachytherapy treatment in a human lung,
comprising: extending an applicator through the skin into the lung
tissue and into a resection cavity, said applicator having an
inflatable balloon at its distal end, the balloon being deflated
upon insertion, the applicator having a shaft supporting the
balloon, and defining an internal channel adapted to receive a
catheter carrying a source of ionizing radiation near the distal
end of the catheter, and the shaft including at a proximal end a
hub through which the catheter can be inserted, and the hub
including provision for inflating the balloon through the shaft,
inflating the balloon within the resection cavity, irradiating
tissue within the lung and adjacent to the resection cavity by
means of the source carried by the catheter within the inflated
balloon; providing a suction sleeve about the shaft including
positioning the suction sleeve so that a distal end thereof is in
communication with a pleural cavity of the patient to drain or
evacuate fluid; and at least partially withdrawing the applicator
after being inserted.
17. The method of claim 16 including providing the suction sleeve
as slideable along the shaft between withdrawn and advanced
positions.
18. The method of claim 17 including providing the distal end of
the suction sleeve as open to define a suction port.
19. The method of claim 18 further including sliding the suction
sleeve so that the suction port is in communication with the body
cavity.
20. The method of claim 19 including providing a knob on the
suction sleeve to assist in sliding the suction sleeve.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 11/978,147, filed Oct. 26, 2007, entitled
BRACHYTHERAPY APPARATUS AND METHOD FOR USE WITH MINIMALLY INVASIVE
SURGERIES OF THE LUNG, the entire disclosure of which is herein
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This invention pertains to minimally invasive surgery of the
lung. In particular, it applies to application of brachytherapy
techniques directed primarily to lung or pleural tissue surfaces
exposed by or created as a result of tumor resection or the
presence of primary cancer of the pleura. As with other tumor
resection procedures, and even when pathology shows "clear"
margins, there is potential for disease recurrence from diffuse
proliferative disease in the resected surfaces. Balloon
brachytherapy as an adjuvant follow-up to resection has been shown
to reduce the likelihood of such recurrent disease.
[0003] Recent advances in surgical treatment of proliferative
diseases of the lung include endoscopic procedures conducted
through, and directed to lesions near the bronchi, and
alternatively, video-assisted, minimally-invasive thoracic surgery
directed to more peripheral disease and performed through incisions
providing access to the thoracic cavity.
[0004] Today with early stage carcinoma of the lung, particularly
in peripheral portions of the lung, treatment consists of resecting
a wedge-shaped portion of lung through small incisions between
adjacent ribs. If a wedge resection is inadequate to excise the
entirety of the tumor, a lobectomy may be performed, removing a
complete pulmonary lobe. Visualization is provided by camera or
conventional fiber optic means mounted on a thoroscope and monitor
display, although other state-of-the-art modalities can be used.
Percutaneous or other methods or small incisions are used to
introduce the necessary instrumentation, and with newer, minimally
invasive techniques, conventional rib spreading is not required.
The absence of rib spreading greatly reduces pain and hastens
patient recovery, but narrows instrument access to a few small,
discrete points on the rib cage. In order to provide adjuvant
brachytherapy, methods and apparatus are needed that are compatible
with the methods described above, and preferably without requiring
additional access beyond that already established during
resection.
[0005] With the intrabronchial approach to treatment of
obstructions or lesions, a flexible bronchoscope with a working
channel is generally employed in the affected bronchus while the
remaining bronchial tree provides intraoperative ventilation. The
bronchoscope also comprises either camera or fiber optic means to
provide monitor display. Other instrumentation, preferably
including that for follow-up brachytherapy, must be flexible, and
of appropriate diameter for operation from within the working
channel in order to be compatible. Extra or intrabronchial
procedures often involve removal of a diseased section of bronchus,
after which the exposed ends are usually approximated, either by
suture or staple methods. Adjuvant brachytherapy may also be
indicated after extra or intrabronchial surgery.
[0006] Brachytherapy practice traditionally comprises positioning a
radiation source within target tissue and delivering a therapeutic
dose of radiation, often from within a balloon, without overdosing
either target or adjacent tissue. One particularly useful class of
radiation sources are miniature electronic x-ray tubes which may be
switched on and off at will, or which can be modulated with respect
to either penetration depth (by controlling acceleration voltage of
the x-ray tube) or dose intensity (by controlling filament
current). These tubes are usually mounted at the end of a power
supply cable and can emit isotropically or can be directional,
emitting through a predetermined solid angle. One reference
describing the principles and construction of such tubes is Atoms,
Radiation and Radiation Protection, Second Edition, John E. Turner,
Ph.D., CHP, 1995, John Wiley & Sons, Section 2.10. By contrast,
isotope sources cannot in principle be modulated, and in addition
require both isolation of the patient during radiotherapy and
special facilities and apparatus to assure safety of personnel.
[0007] A minimum therapeutic absorbed dose (the prescription dose)
is selected by the therapist to be delivered to all of the target
tissue. Because dose generally decreases exponentially with
distance from the source, accurate dose delivery is complicated and
automated treatment planning is generally employed to assure
delivery of a dose to the target tissue which is at least equal to
the prescription dose, but which is also within allowable limits,
thus avoiding substantial necrosis of normal tissue. The
prescription dose may of necessity vary depending on the proximity
of the source to radiation sensitive structures within the anatomy.
Examples would include the skin, heart or other organs, and bone.
Treatment planning is usually automated based on known radiation
source parameters, prescription parameters, and geometry as
determined by conventional imaging of the apparatus within tissue.
Planning usually precedes the treatment delivery.
[0008] A useful device for controlling radiation intensity is an
applicator, preferably a balloon applicator. Balloon applicators
generally determine the interior shape of the target tissue (the
resection cavity) and position the radiation source at a controlled
distance from the tissue to be treated, thus defining treatment
geometry and reducing the radiation intensity exponentially from
spatial considerations. Several other means are available to
moderate the absorbed dose delivered to the tissue. As noted above,
the acceleration voltage applied to the x-ray tube can be used to
limit the penetration depth of the radiation. The filament current
can be reduced to lower emitted intensity, or in fact, to eliminate
emissions altogether. Once output emission characteristics are
determined by selection of x-ray tube input parameters, shielding
can be used to reduce radiation intensity, or to control the
direction of emissions, statically or dynamically as therapy
progresses. Such shielding and attenuation methods for x-ray tubes
are described in copending application Ser. Nos. 11/385,255,
11/471,277 and 11/471,013, each of which is incorporated herein in
their entirety by reference.
[0009] Balloon applicators are known, for example those described
in U.S. Pat. No. 6,413,204. In general, such applicators comprise a
balloon mounted on a shaft proximate the distal end of the shaft,
and further comprise at least one source guide to position the
source at a known distance or distances from the balloon (and
tissue cavity) surface. Fluid circuits can be provided
communicating from outside the patient to the interior of the
balloon for inflation purposes, or to outside the shaft and/or
balloon for example for suction purposes or administration of
anesthetic or therapeutic agents.
SUMMARY OF THE INVENTION
[0010] After a lung wedge resection or lobectomy, and preferably
after pathology determination of clean margins, adjuvant
brachytherapy may be indicated. If so, an applicator with a balloon
is positioned within the resection cavity as the lung is closed,
but before the chest cavity is closed, with the applicator shaft
extending outside the patient. (Optionally, the skin may be closed
as well, but it may be desirable to close the skin later such that
pleural access is available for suturing or stapling after removal
of the brachytherapy apparatus.) For this minimal access resection
method (usually between the ribs), a substantially rigid applicator
shaft is likely preferred. The balloon is then inflated. If
necessary to close the lung effectively, the bronchoscopic methods
of U.S. Patent Application Publication No. 2005/0137714 may be
employed.
[0011] Once the balloon is properly positioned and inflated, the
lung will likely self-expand or may be gently inflated. If desired,
the chest may be imaged using conventional or state-of-the-art
methods to assure that the lung tissue closely conforms to and
surrounds the balloon as closely as possible. Advantageously, a
fluid suction circuit in the applicator leading from outside the
patient to outside the shaft of the applicator in communication
with the pleural cavity is helpful for preventing or reducing
pneumothorax, and facilitating proper lung inflation. The port
intended to open into the pleural cavity is preferably adjustable
along the shaft of the applicator such that it may be properly
positioned and suction can be applied as desired. Alternatively,
the suction circuit can comprise a valve, and/or the circuit can be
used to instill therapeutic agents.
[0012] When the apparatus is properly situated and the anatomy is
in conformance with the balloon, imaging of the site can be
performed, and the information used to help create the treatment
plan. Such information can include the shape of the treatment
cavity, and the location of the cavity relative to anatomical
structures, some of which could lie within the range of target
tissue, or by their anatomical position, be at risk of inadvertent
exposure during delivery of the prescription. If the latter occurs,
radiation sensors capable of communication with the central
controller can be applied to the skin, or positioned adjacent such
structures by needle means or implanted during the surgical
procedure. Output from these sensors can be used to eliminate
over-exposure to radiation--inadvertent or otherwise.
[0013] The source, preferably mounted on a power cable or catheter,
can then be inserted into the source guide, properly positioned,
and optionally manipulated within or proximate the balloon to
deliver the prescribed dose. Such manipulation can be manual, or is
preferably automated in accordance with the treatment plan. The
treatment plan may be delivered intraoperatively in its entirety,
or may be delivered in fractions over time, in accordance with the
treatment plan. At completion of treatment, the apparatus is
removed from the body.
[0014] For application of brachytherapy after a bronchial resection
or for treatment/palliation of an inoperable lesion (cancer), an
applicator with a flexible shaft is advanced through the working
channel of the bronchoscope. Once properly situated within a
bronchus, the balloon is inflated, positioning the source guide
accurately relative to the tissue to be treated. The source can
then be positioned and radiotherapy begun. Because of the tubular
nature of the resection, radiation delivery may be from within one
positioning of a relatively short balloon with the source position
fixed or translated within the balloon, or can be delivered from
successive balloon positions with iterations of inflation,
radiation, and deflation. Alternatively, an elongated or
sausage-shaped balloon may be used. Because of the limited diameter
of the bronchus, the methods and apparatus of co-pending U.S.
application Ser. No. 11/925,200, have applicability here, and this
teaching is incorporated herein in its entirety by reference.
[0015] The apparatus and methods of this invention may be employed
to facilitate adjuvant brachytherapy used in conjunction with the
procedures described above. The features and elements disclosed may
be combined in other embodiments as will occur to those of skill in
the art, but these variations are to be considered within the scope
of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention description below refers to the accompanying
drawings, of which:
[0017] FIG. 1A is a schematic side view in partial section of an
applicator of the invention passing through the skin and chest wall
of a patient and extending into a lung;
[0018] FIG. 1B is a detail of the apparatus of FIG. 1A showing a
suction sleeve with its open end positioned just within the pleural
cavity of a patient;
[0019] FIG. 2A is a schematic side view in partial section of an
alternate applicator of the invention comprising a channel of a
suction circuit within the applicator shaft bore, the channel
having a port opened to communicate with the volume of the pleural
cavity;
[0020] FIG. 2B is a section view of the applicator shaft of FIG. 2A
showing the suction channel;
[0021] FIG. 3 is a schematic perspective view of a bronchoscope
positioned within a section of bronchus, the bronchoscope having a
intraluminal balloon applicator positioned and inflated within the
resection portion of the bronchus;
[0022] FIGS. 4A and B are progressive positions of an applicator
similar to that of FIG. 3, but intended for multiple positioning
within the bronchus being treated; and
[0023] FIG. 5 is an schematic perspective view of an elongated
balloon on a bronchial applicator of the invention, though which a
radiation source may be translated in order to treat an elongated
section of bronchus.
DETAILED DESCRIPTION
[0024] FIG. 1A is a side view in partial section showing an
applicator 10 of the invention passing through the chest wall 12 of
the patient. The shaft 14 of the applicator extends from a
conventional hub 16 outside the patient into a balloon 18
positioned within a resected portion of the lung 20. The chest wall
12 includes the skin 22, ribs 24, and parietal pleura 26. The space
between the parietal pleura 26 and the visceral pleura (not shown)
covering the lung 20 defines the pleural cavity 28.
[0025] The hub 16 of the applicator 10 includes a side port 30 for
inflating the balloon 18 and a central port 32 for advancing a
radiation source 34 and source catheter 36 into the balloon 18. The
central port includes a conventional seal (not shown) to avoid
fluid leaks around the catheter through the hub. The shaft 14
extends from the hub into the balloon, and the balloon inflation
medium passes through the shaft around the catheter 36 to a port 37
opening into the interior of the balloon 18 (see flow arrows). The
interior of the shaft serves as a source guide, and accurately
positions the source 34 within the balloon. Preferably the balloon
is fastened to the shaft at both its distal end 38 and proximal end
40.
[0026] A suction sleeve 42 is located coaxially and slideably over
the applicator shaft 14 as shown in FIG. 1B, just distal of the hub
16, and comprises a knob 44, a conventional seal 45 therein at its
proximal end 46, sealing the interior of the sleeve 42 and outside
of the shaft. A suction port 48 is provided near the proximal end,
and in communication with the annulus between the sleeve 42 and the
shaft 14. In use, the applicator 10 is advanced into the anatomy
until the balloon 18 is properly positioned in the target tissue,
i.e. in a resected portion of the lung. The sleeve is then slid on
the shaft until the distal end is just within the pleura and in
communication with the pleural cavity. If desired, apparatus for
locking the sleeve position axially on the shaft may be provided,
for example a locking nut or set screw (not shown). Thus upon
application of suction, the pleural cavity 28 is drained and/or
evacuated, facilitating expansion of the lung 20.
[0027] As an alternative to the shaft being attached to both the
proximal and distal extremities of the balloon as depicted in FIG.
1A, the shaft need only communicate with the interior of the
balloon as shown in FIG. 2A. The shaft 64 can extend into the
volume of the balloon 65 and stop. The inflation medium passes from
the port 68 into and through the annulus between the interior of
the shaft 64 and the outside of the catheter 36 and into the
interior of the balloon.
[0028] In the alternate applicator 60 of FIG. 2A, there is no
suction sleeve as in FIG. 1A, but rather a suction channel 62
within the bore of the shaft 64. The channel 62 is shown in section
view in FIG. 2B taken at the port 72. Again as in FIG. 1A, the
chest wall 12 includes the skin 22, ribs 24, and parietal pleura
26. The space between the parietal pleura 26 and the visceral
pleura covering the lung 20 defines the pleural cavity 28. The
balloon 65 of this embodiment is only secured to the shaft 64 at
the balloon proximal end. This fastening is shown as an alternate
to the preferred fastening at both distal and proximal extremities
of the balloon 65 as shown in FIG. 1A. The hub 66 of this
embodiment comprises one port 68 for balloon inflation as described
above in connection with FIGS. 1A and 1B, and a suction port 70 in
communication with the suction channel 62 in the shaft 64 and the
port 72. The distal end of the channel 62 is blocked (for example
with a plug 63) so as not to communicate with the interior of the
balloon. In use, and maintaining the sterile surgical field, the
balloon is positioned properly within the resected tissue, and the
axial location of the pleural cavity 28 is marked on the shaft over
the suction channel 62. The applicator is then withdrawn from the
anatomy sufficiently for the practitioner to pierce or cut a port
72 into the suction channel at the mark. Once the port is made, the
applicator is reinserted into the anatomy so the port 72
communicates with the pleural cavity 28, the balloon 65 is
inflated, and the source 34 and the source catheter 36 are inserted
to commence radiation treatment. Suction may then be applied to the
suction channel 62 via the hub suction port 70, thus draining the
pleural cavity 28 of any fluid therein.
[0029] Alternatively, the suction channel 62 may have a long slot
(not shown) communicating outside the shaft 64 in the manner of the
port 72, but extending from the hub 66 distally and stopping short
of communication with the interior volume of the balloon 65. A
piece of sterile tape (not shown) may be applied to the exterior of
the shaft 64 from the hub 66 to just inside the pleural cavity,
thereby forming a closed suction circuit to drain the pleural
cavity in a manner similar to that described above.
[0030] With either the applicator of FIG. 1A or 2A, once the
balloon is properly located and inflated and the suction circuit
established (if needed), radiotherapy is commenced. The planed
therapy can be delivered in one dose application, or can be divided
into fractions and spread out in time. One treatment is complete,
the apparatus is removed, and any closing required is performed in
a conventional manner.
[0031] FIG. 3 shows a bronchoscope 80 positioned in a portion of a
bronchus 82 which has been resected and subsequently approximated.
A balloon applicator 84 is shown protruding from the working
channel of the bronchoscope 80, with the applicator balloon 86
inflated near the point of bronchus reapproximation 88. With
bronchoscopic applications, the applicator shaft is preferably
flexible so as easily to follow the working channel of the
bronchoscope. A radiation source and flexible source catheter
(neither shown) may be advanced into the balloon 86 from outside
the patient, properly positioned, and radiotherapy commenced in
accordance with a treatment plan.
[0032] If desired in order to deliver radiotherapy to a longer
section of bronchus, the balloon 86 may be deflated from its
original position, moved within the bronchus, reinflated and
further radiation delivered. Such stepping is illustrated in FIGS.
4A and 4B, and can be provided with use of a manipulator of the
sort depicted in FIG. 3 of copending application Ser. No.
11/925,200 referenced herein. Because of the small scale of the
bronchial anatomy, the eccentric source guides and methods of Ser.
No. 11/925,200 may be advantageously utilized for treatment from
within a balloon positioned in the bronchi. Alternatively to
stepping, a sausage-shaped balloon 90 with two-point fastening to
the shaft 92 may be used as depicted in FIG. 5. The hollow shaft 92
acts as a source guide for a source 34 which is translated within
the balloon 90 in accordance with the treatment plan. After
completion of treatment, the applicator and bronchoscope are
removed.
[0033] With the methods and apparatus of this invention, the
advantages of brachytherapy can be made available to virtually all
patients undergoing surgery of the lung. Most notably, these
advantages include less normal tissue exposure to radiation since
no external radiation sources are used, fewer safety requirements
to be observed (with x-ray tubes, no bunker facilities are
required) and hence virtually any medical facility can perform the
radiotherapy, and greatly reduced capital requirements and costs of
treatment.
[0034] The above described preferred embodiments are intended to
illustrate the principles of the invention, but not to limit its
scope. Other embodiments and variations to these preferred
embodiments will be apparent to those skilled in the art and may be
made without departing from the spirit and scope of the invention
as defined in the following claims.
* * * * *