1. Field of the Invention
The present invention concerns a method and a device and an apparatus system for prostate cancer therapy.
2. Description of the Prior Art
According to the modern prior art, two standard methods can be selected to treat the prostate tumor (PCa), namely prostatectomy (the radical removal of the prostate) or what is known as active surveillance (“watchful waiting”).
The diagnosis normally takes place by palpation and/or by determining the PSA value in the blood of the patient. Since neither method allows a definitive conclusion as to whether PCa is present or not, in the event of suspicion a punch biopsy of the prostate is conducted. Under ultrasound monitoring (TRUS), the urologist punctures the prostate with a biopsy needle according to a specific puncture pattern, since PCa is normally not detectable in ultrasound. For example, 12 biopsy specimens are extracted—named according to their approximate extraction point (left/right; apex/middle/base; peripheral zone/transitional zone)—and sent to a pathologist for histological assessment. The result is provided to the urologist after a few days or weeks. Due to the blind extraction, often all biopsy specimens are negative, such that often a repeat biopsy is required for further clarification. So that the prostate can be punctured at different points in the repeat biopsy, knowledge of the extraction points of the previous biopsy is required. Items known as biopsy grids are used for this purpose, for example. These are plate-shaped structures with a predetermined hole pattern that are affixed to the biopsy apparatus, for example. Given a repeat biopsy, the biopsy needle is directed through other holes of the grid.
Using the histology data that is possibly present after multiple biopsies, the urologist in consultation with the patient makes a decision about a therapy, most often for a complete removal of the prostate with the known consequences of incontinence and impotence. The procedure is conducted either as an open operation or as a RALP (Robot Assisted Laparoscopic Prostatectomy). In addition to this, other forms of therapy exist, for instance hormone therapy and different forms of local therapy such as radiation therapy, brachytherapy and ablative methods (for instance cryotherapy and laser therapy). In local therapy, the entire prostate is normally subjected to an ablation. The reason for this is the poor ability to depict PCa with conventional imaging methods, and therefore the lack of knowledge about the precise position and propagation of PCa in the prostate. At best, given the presence of one or two positive findings with low Gleason score in one prostate half, a hemi-ablation is considered. Therefore, generally the treatment has previously entailed a massive damage to healthy prostate tissue, with the known side effects. With newer biopsy apparatuses, the extraction points of the biopsy specimens can be stored. Nevertheless, these apparatuses do not allow a targeted therapy of only the tumor tissue. This is due to the fact that during the course of the therapy the prostate has varied in size, shape or position relative to the point in time of the biopsy. The bladder presses on the prostate and alters its shape and/or position more or less depending on the fill level. Such a variation can also be caused by a rectally inserted apparatus, for instance an ultrasound probe. Therefore, it is also the case that an exact focusing (localization) of the therapy on a tumor cannot take place with the cited biopsy apparatuses. This is particularly true for PCa in the early stage, which already can barely be detected with conventional imaging methods due to its low volume.
An object of the invention is to provide a method, a device and an apparatus system that allow focused therapy of a prostate tumor in which healthy prostate tissue is damaged as little as possible.
This object is achieved by a method according to the invention, in which a treatment of the tumor occurs only as necessary even during the therapy session, with factors affecting position and size of the prostate—such as bladder fill level or a different position of a newly rectally inserted ultrasound switching head—being excluded, or at least having only an insignificant effect.
In the method in accordance with the present invention, during the course of a treatment session in the context of prostate cancer therapy, the prostate of a patient is subjected to a diagnostic examination at different locations to identify the presence or absence of a tumor at the respectively different locations. In the case of a positive diagnosis (i.e., a diagnosis that a tumor is present at a respective location of the prostate, only the location in the prostate at which the positive diagnosis occurred is therapeutically treated during the treatment session.
An extracted tissue sample can be conducted during a single treatment session with the use of a diagnostic unit that embodies a device for histological assessment, such that the finding is present even during the treatment session. A PCa therefore can be treated immediately, for instance with the use of laser beams. In contrast, given a conventional procedure in which the tissue samples are examined by an external laboratory the finding is only available after a few days or weeks.
The histological assessment can be based on a known biopsy, meaning that tissue samples are extracted at specific points of the prostate, and these samples are subjected to a histological assessment immediately on site—i.e. while a patient is located on the patient table within the scope of a treatment session. In order to ensure the ability for a later re-location of a specific, positively assessed point of the prostate, the extraction points are marked or acquired and stored with the aid of an imaging method. For example, marking with a biopsy grid is possible.
A spatially precise acquisition and storage of extraction points is possible with the aid of an imaging method and a software to store the respective spatial positions of the extraction points. For example, such a system is the system under the name “TargetScan”, distributed by the company “Envisioneering Medical Technologies”, St. Louis, Mo. 63114. In a preferred method variant, the biopsy is implemented with the use of a device having a hollow needle and a biopsy needle that is movable and can be directed within the inner chamber of said hollow needle. After the tissue extraction, the hollow needle is left with unchanged position in the prostate and is only removed if a negative finding results. In the case of a positive diagnosis, a therapy—for example a laser ablation of the affected location—takes place via the internal chamber of the hollow needle. Since its position is unchanged relative to the point in time of the tissue extraction, a pinpoint therapy is possible. A storage of the spatial coordinates of the extraction point with the assistance of an imaging method and a storage medium is not required for this. All methods that can be implemented with the aid of a therapy element which can be introduced into the internal chamber of the hollow needle (thus rod-shaped, wire-shaped or fibrous elements) are thus suitable for the therapy. A device suitable for these method variants comprises a hollow needle; a biopsy needle bearing an extraction element at its forward end (the end serving for the extraction of a tissue sample); and a therapy element that, for example, is an optical waveguide with which a laser ablation can be conducted. However, other therapy forms such as cryotherapy, brachytherapy, PDT, electroporation and the administration of chemotherapeutics can also be considered.
In a preferred embodiment, an in vivo diagnosis in which a point of the prostate is charged via an optical waveguide with an electromagnetic radiation and the fluorescence response of the tissue is detected. Such a method is described in European Patent Application Nr. EP 09006583.0, the contents of which are incorporated herein by reference. In this method, living, tumor-afflicted tissue is detected in that an electromagnetic radiation is emitted towards this and the decay response of an eigenfluorescence intensity of the tissue (which eigenfluorescence intensity is excited by the electromagnetic radiation) is acquired with temporal and spectral resolution. A diagnosis result can already be obtained within a few seconds with such a method, which can also be implemented in a sample of living cells that is extracted via biopsy. For in vivo assessment it is advantageous that storage of diagnostically examined locations is not required.
In the event of a tissue extraction by means of a biopsy, to implement the method a device that comprises a hollow needle (the hollow needle embodying a biopsy needle bearing an extraction element at its forward end, the forward end serving for the tissue extraction, and a therapy element serving for therapeutic action at a point of prostate) instead of a conventional biopsy device. The biopsy needle and the therapy element—for example an optical waveguide—are designed so that they can be introduced into the hollow needle, advantageously singularly. However, the hollow needle could also be designed so that the biopsy needle and optical waveguide can be accommodated simultaneously. In addition to an optical waveguide with which a laser ablation can be conducted, a therapy element can also be considered with which the aforementioned therapy methods (such as cryotherapy etc.) can be applied.
In the case of an optical waveguide as a therapy element, it is advantageous that this is not switched out after the diagnosis, but rather that only therapeutic active laser light must be fed in. The optical waveguide is thus usable for diagnosis and therapy. For the case that a different therapy form such as laser ablation should be used, the device is designed similar to as is described further above, thus comprises a hollow needle, an optical waveguide for diagnostic purposes and a therapy element. The hollow needle is designed so that it can advantageously accommodate only one of the cited parts. In the in vivo method it is the case that the hollow needle containing the optical waveguide serving for diagnosis remains at the respective point after implementation of the diagnostic with unchanged position and alignment. A therapy taking place via the inner chamber of the hollow needle after the diagnostic can therefore be directed with pinpoint accuracy towards the tumor, and possibly its environment.
In the in vivo variant, the fluorescence of a fluorescence marker (known from DE 10 2007 028 659 A1, for example) can also be utilized in addition to the eigenfluorescence of the examined tissue (as described in Patent Application Nr. EP 09006583.0). Such a fluorescence marker is formed from a fluorescing molecule and a ligand, wherein the latter specifically binds to tumor tissue of the prostate. The fluorescence marker (supplied via the bloodstream, for example) accumulates [enriches] in tumor tissue, such that this is visible due to the fluorescence caused by exposure with light. For example, for detection of the fluorescence a fiberglass bundle can be used here and also in the diagnostic method known from the Patent Application Nr. EP 09006583.0. Naturally, the diagnosis based on fluorescence can also be applied extracorporeally given a sample extracted from the prostate.
An apparatus system suitable to implement a method of the type described above has a diagnostic unit and a therapy unit for focal therapy treatment of the prostate, wherein the diagnostic unit includes a device to histologically assess prostate tissue. With this basic configuration of medical apparatuses, for the aforementioned reasons a focal therapy can be implemented with pinpoint accuracy within the scope of a treatment session. It is advantageous for the apparatus system to also include an imaging device.
A workstation with an apparatus system to implement the method illustrated above is shown in a significantly schematic manner in
In the course of a biopsy, samples are extracted at multiple different points of the prostate. In order to monitor the tissue extraction visually on the one hand and, if necessary, to store the extraction points 13 recorded in the image on the storage medium of a PC (not shown), a device is present for imaging 14. For example, this comprises an ultrasound apparatus 15 with a rectally insertable ultrasound head 16. The ultrasound apparatus 15 is connected via a data line 17 with a computer (not shown) that in turn reproduces the prepared image information on a display 18. In addition to TRUS (transrectal ultrasound), other imaging methods such as MR or MR-US fusion can also be used. Different MRI protocols (T2W, DWI, DCE and MRS, for example) can thereby be used to show and delimit the tumor. Novel ultrasound methods such as 3D-TRUS, CE-US and elastography, or even molecular (for example optical) imaging methods can also be used. In addition to a storage of the spatial coordinates of an extraction point 13 with the aid of an imaging method an a storage medium, the use of what are known as biopsy grids (not shown) is also known. These are plate-shaped structures with a grid of bores, for example. The individual bores are numbered, such that an extraction point is defined by the number of the bore via which the hollow needle 7 has been inserted. The circles 11 rendered in the image of the prostate 12 (reference character 5=urethra) in
The diagnostic unit 3 comprises a device 23 for histological assessment of prostate tissue. Such devices are known as such and are used in laboratories (for example) to which tissue samples have previously been sent for assessment. Since, according to the invention, diagnosis and therapy are conducted during a single treatment session, such devices or methods which already allow a finding after a short period of time (for example in less than 2 minutes) are naturally advantageous. Such a method described in EP Application Nr. 09 006 583.0 was already mentioned above. It operates with the aid of electromagnetic radiation with which the living tissue is excited to an eigenfluorescence radiation. The intensity of the eigenfluorescence is detected with a detector with constant scan rate for at least one wavelength, the difference autocorrelation function C(t) of the intensity decay response is determined with the determined intensity measurement values. From this the fractal dimension DF for the respective exposed tissue is then calculated, and the value of the fractal dimension is compared with a tumor-specific threshold. If the threshold is exceeded, the exposed tissue of the tissue sample can be classified as afflicted with tumors. Additional details with regard to this method are to be learned from the cited EP Patent Application. The supply of the magnetic radiation can take place with the device described above, which comprises a hollow needle 7 and an optical waveguide 24. This thus represents the assessment [finding] device 23 or is at least a part of this.
The therapy unit 4 includes at least one device suitable for PCa therapy. All prevalent devices and methods to treat PCa can be used. This can be a device with which a therapy can be implemented from the group of: radiation therapy; HIFU (high-intensity focused ultrasound); cryotherapy*; brachytherapy* (seed/HDR); PDT* (photodynamic therapy); laser ablation*; electroporation*; administration of a chemotherapy agent*. The methods marked with * are implemented with the aid of elongated—for example rod-shaped, wire-shaped or fibrous—therapy elements. If a device with a hollow needle 7 (as in a variant of the proposed method) is now used for biopsy or diagnosis, after the tissue extraction or, respectively, diagnosis the inner chamber 8 of the hollow needle 7 can be exchanged for a different therapy element suitable to implement the cited therapies. Since the position of the hollow needle 8 remains unchanged, a focal therapy can take place with pinpoint accuracy with one of the cited methods and be limited to the PCa, and possibly to a tissue area surrounding this. Regions of the prostate 12 that are not afflicted by PCa thereby remain intact, such that in many cases the side effects—such as impotence and incontinence—linked with a complete removal of the prostate or with a large-volume ablation of prostate tissue do not occur.
In conducting an in vivo diagnosis, via an optical waveguide 24 (
An additional possibility of focal therapy is shown in
Although modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.
Number | Date | Country | Kind |
---|---|---|---|
102010028105.0 | Apr 2010 | DE | national |