Prostate cancer ablation

Abstract

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.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60 / 972,698 (Attorney Docket No. 26533A-000700US), filed Sep. 14, 2007, the full disclosure of which is incorporated herein by reference.BACKGROUND OF THE INVENTION[0002]The present invention relates generally to electric field delivery to a prostate tissue of a patient. More particularly, the present invention provides systems and methods for delivering alternating current and controlled, mild heating to a prostate tissue of a patient for destruction of cancerous and / or hyperplastic tissue.[0003]The prostate gland is a walnut-sized gland located in the pelvic area, just below the outlet of the bladder and in front of the rectum. It encircles the upper part of the urethra, which is the tube that empties urine from the bladder. The prostate is an important part of the male reproductive system, requiring male hormones like testosterone to fu...

AI Technical Summary

Benefits of technology

[0013]Thus, the present invention includes systems and devices, as well as methods for delivering electric fields to prostate tissue. Electric field delivery can include establishing an electric current flow through a target tissue region comprising prostate tissue so as to preferentially ablate or destroy cancerous cells in the target tissue region.

Problems solved by technology

In addition to risks of morbidity due to prostate cancer, most men over 60 years old experience partial or complete urinary obstruction due to enlargement of the prostate.

Ionizing radiation has the effect of damaging a cells DNA and limiting its ability to reproduce.

During EBRT, the rays pass through and can damage other tissue on the way to the tumor, causing side effects such as short-term bowel or bladder problems, and long-term erectile dysfunction.

Radiation therapy can also temporarily decrease energy levels and cause loss of appetite.

Once positioned in the tissue, the radiation from the seeds extends a few millimeters to deliver a higher radiation dose in a smaller area, causing non-specific damage to the surrounding tissue.

The seeds are left in place permanently, and usually lose their radioactivity within a year.

Internal radiation also causes side effects such as short-term bowel or bladder problems, and long-term erectile dysfunction.

Internal radiation therapy can also temporarily decrease energy levels and cause loss of appetite.

Most significant, however, is the change in the texture of the prostate tissue over time, making the subsequent removal of the gland, as described above, complicated and difficult as a secondary treatment.

Since the microwave probe delivers substantial heating that can cause unwanted damage to healthy tissues or to the urethra, devices typically make use of a cooled catheter to reduce heating immediately adjacent to the probe.

In this procedure, the prostatic tissue immediately around the urethra and the urethra itself are deliberately spared from receiving an ablative level of heating by attempting to keep the temperatures for these structures at less than 50 degrees C. Unfortunately, controlling the tissue heating due to the applied microwave energy is difficult and unintended tissue damage can occur.

Further, destruction of tissue beyond the cooled region is indiscriminate, and control of the treatment zone is imprecise and limited in the volume of tissue that can be effectively treated.

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