Robots to treat prostate cancer

I-Street

March 2002

By Jeff Meredith

It is easy to associate robots with auto assembly lines and novelty home and consumer offerings that are only attainable for the affluent and gadget crazy: robotics lawnmowers, snow blowers and vacuum cleaners. But there is a practicality to surgical robots that few can deny and Burdette Medical Systems, Inc. (BMSi), a Champaign, Ill.-based developer of next generation medical devices, is poised to become a major player in this market.

Collaborating with the Computer-Integrated Surgical Systems and Technology (CISST) Engineering Research Center at Johns Hopkins University, Burdette recently used a surgical robot to guide radioactive seed implants for the brachytherapy treatment of prostate cancer. The robot was controlled with interplant, an ultrasound image-guidance computer system for brachytherapy developed by Burdette.

Brachytherapy, in which radioactive materials are placed close to a malignancy in order to attack it, has relied upon physicians' ability to accurately place the seed implants. Complications can easily arise, such as damage to a patient's surrounding anatomy - the bladder, rectum and urethra - says Dr. E. Clif Burdette, president of BMSi. Burdette hopes that surgical robots can avert such side effects and the work first undertaken by his company and Johns Hopkins a year and a half ago is quickly moving toward that goal.

"It's the only system capable of providing live, real-time intra-operative dose information and feedback as the radiation systems are planted," said Burdette. "[Johns Hopkins] approached us to look at a role robotic surgery might play in better placement. We took advantage of a program initiative from the National Cancer Institute (NCI) and we submitted an application for developing an interactive approach that would utilize the capabilities of our software - interactive dose feedback to the doctor, the ability to have a surgical robot deliver radiation sources into the proper place for the implant."

Burdette and Johns Hopkins have just finished the first year of a $1.6 million, three and a half year program. In January, a robot was tested using Burdette's software to deliver a mock implant. A phantom, or anatomical model, was created with all of the lower torso anatomy present - much like what medical students would use in training. Dummy radiation sources were implanted by the robot to complete the procedure. Now comes phase two: the ability to drive in needles at any angle.

"As the robot inserts the needle, our software knows where the needle should be and can overlay a display for the doctor to see," said Burdette. "Feedback will tell the robot if it's not quite on track, correct its trajectory while it's inserting. That's the next major level of advancement."

The third phase of the project will involve clinical trials, a possibility in 2003. Burdette's technology is not just limited to prostate treatment; he hopes to guide other minimally invasive procedures. Burdette anticipates the release of a product later this year that could guide the targeting of external beam radiation therapy for cancer involving soft tissues.

"There are some difficulties with soft tissues inside the body that don't show up on the CT [Computerized Tomography], their position has to be inferred from other anatomy that can be seen," explained Burdette. His company's technology could help better pinpoint soft tissue location and use that data to plan and guide external radiation, which is often targeted with surface markers placed on a patient's body.  Soft tissues have a tendency to move around, however, meaning that uniform markers are not sufficient.

Burdette Medical Systems, Inc., was founded in 1997 and its early development was aided by SBIR grants. In 1997, Illinois delivered close to $100,000 for the company's brachytherapy guidance system and an additional $617,000 was earned for the ultrasound guided radiation therapy for prostate cancer. The company "was not venture backed in the traditional sense," said Burdette, noting he invested some funds initially and that the company did a private offering of equity securities for another round of financing last year. The company has grown from four employees in early 1998 to a staff of 25. This number includes five employees in St. Louis who were a part of Tayman Medical, a medical product development company acquired in 2001. Tayman has designed hardware - called AccuSeed - for prostate seed implantation, making for a logical convergence of technology.

"Taymen makes hardware for holding the grid used to guide the implants for prostate radiation. They had a very solid product and a large install base that actually had quite a bit of sales in Europe as well as the US," said Burdette. "We have a full line of products for prostate treatment, now we have all the hardware."