PROSTATE CANCER ABLATION
Methods and systems for delivering electrical energy and controlled, mild hyperthermia to a prostate tissue of a patient for destruction of cancerous and/or hyperplastic tissue. A method includes positioning a plurality of electrodes in a target tissue region comprising the prostate tissue, and establishing an alternating electrical current flow through a volume of the prostate tissue to induce mild heating and destruction of cancerous cells in the volume.
1 . A method of delivering electric fields to a prostate tissue of a patient, comprising:
positioning a plurality of electrodes in a target tissue region comprising the prostate tissue; and
establishing an electrical current flow radially or in a plurality of different directions through a volume of the prostate tissue so as to preferentially ablate cancerous cells in the volume, the electrical current flow comprising a frequency of less than about 300 kHz.
2 . The method of claim 1 , wherein establishing the current flow comprises applying an alternating electrical current to the volume to provide an electric field extending radially outward from a current flow center.
3 . The method of claim 2 , wherein the electric field extending radially outward from a current flow center is established by a plurality of electrodes positioned to define an ablation volume, with electrodes positioned around the volume activated in pairs to establish current flow between electrodes.
4 . The method of claim 1 , further comprising positioning a plurality of secondary electrodes to at least partially define an ablation volume comprising the target tissue, positioning a center electrode within the ablation volume, and establishing a current flow field between the center electrode and the secondary electrodes extending radially outward from a current flow center.
5 . The method of claim 1 , wherein positioning the electrodes comprises advancing a probe comprising plurality of electrodes to the target tissue region.
6 . The method of claim 5 , wherein the probe is advanced through a surgical incision, a percutaneous puncture, a perineal, a transurethral, or transrectal access procedure.
7 . The method of claim 1 , wherein establishing the current flow includes heating the target tissue region to an average temperature from about 40 degrees C. to about 48 degrees C.
8 . The method of claim 1 , further comprising surgically removing at least a portion of the prostate or performing a brachytherapy procedure following electric field delivery.
9 . The method of claim 1 , further comprising monitoring a patient's PSA level following electric field delivery to detect prostate tissue ablation.
10 . The method of claim 1 , wherein the positioning comprises positioning electrodes in the prostate tissue and adjacent to or around the urethra of the patient for treatment of benign prostatic hyperplasia (BPH).
11 . The method of claim 1 , comprising delivering electrical current substantially throughout the volume of the patient's prostate during treatment.
12 . The method of claim 1 , comprising maintaining for a period of treatment an average target tissue region temperature below 50 degrees C.
13 . The method of claim 1 , comprising maintaining for a period of treatment an average target tissue region temperature from about 40 degrees C. to about 48 degrees C.
14 . The method of claim 1 , comprising maintaining for a period of treatment an average target tissue region temperature from about 42 degrees C. to about 45 degrees C.
15 . A system for preferential destruction of cancerous or hyperplastic cells of a prostate tissue of a patient, comprising:
a plurality of electrodes for advancement and positioning in a target tissue region of the patient comprising prostate tissue;
a control system comprising a power source coupled to the electrodes, and a computer readable storage media comprising instructions that, when executed, cause the control system to:
provide electrical current to the electrodes so as to establish a current flow radially or in a plurality of different directions through a volume of the prostate tissue and to preferentially destroy cancerous or hyperplastic cells in the target tissue region;
maintain an average target tissue temperature of less than about 50 degrees C. during energy delivery.
16 . The system of claim 15 , wherein the plurality of electrodes comprises three or more secondary electrodes positioned to at least partially define an ablation volume and a center electrode within the ablation volume, the electrodes positioned such that during energy application a current flow field is established between the center electrode and the secondary electrodes extending radially outward from a current flow center.
17 . The system of claim 16 , wherein the plurality of electrodes are coupled to a housing of an probe in a fixed position.
18 . The system of claim 15 , further comprising a feedback unit for detecting temperature in the target tissue region.
19 . The method of claim 1 , wherein the control unit and feedback unit are coupled so as to maintain an average target tissue region temperature from about 40 degrees C. to about 48 degrees C. during treatment comprising energy delivery.
20 . The system of claim 15 , the alternating electrical current flow comprising a frequency of about 50 to about 300 kHz.
21 . The system of claim 15 , further comprising an imaging system.