Potential Help for the Prostate

Dec 14, 2015

by Eric Butterman ASME.org

They wake up feeling fine and then hear the words so many men fear: “You have prostate cancer.” Prostate cancer is one of the leading killers of men, but progress thankfully continues to be made in treatment. Kenji Shimada, a professor of engineering in the mechanical engineering department at Carnegie Mellon University is part of a team trying to increase the success rate further with better training through software.

The Skill of Freezing

“The prostate is right below the bladder and in the middle of the prostate is the urethra. It’s pretty small but placed in a delicate space,” Shimada explains. “Open surgery is common for dealing with prostate cancer, but our software focuses on the freezing of the cancerous tissue. It is a heat-transfer simulation. You want to kill the cancer cells but not kill anything else. We use eight to fifteen cryoprobes. You insert the needle between the rectum and are guiding it into the prostate at about 1 or 2 millimeters in diameter and then inject the gas through the needle. You start freezing tissue to create an iceball. On 3D computer graphics, we simulate how the iceballs will connect to each and grow into a different shape.”

Shimada explains that part of the issue is that each person has different shapes and sizes for their prostate and when cancer goes to Stage 2 and Stage 3, the surface of the prostate starts deforming. “It can be getting bumps or a dent. The target shape is different from patient to patient and that’s why it takes practice to have perfect placement of cryoprobes.”

Prostate cancer stats. Source: American Cancer Society. Image: Carnegie Mellon University

Similarity to Video Games

Though what they’re trying to do is serious, the software creation, Shimada says, is similar to video games.

“You place those cryoprobes literally into the 3D model on the computer screen and then start freezing the tissue and you will start seeing the iceballs growing,” he says. “Here you have a chance, without using a physical system or cadaver, to simulate this cryoprobe placing. You eventually get the skill of placing the probe in the right place the first time and that will create a better situation with the iceball that fits the target.”

If you place the probe in bad locations, it will give feedback that it’s too close to the prostate boundary. “We use finite defense methods, a medical method, to simulate the heat-transfer equation,” he adds.

Shimada says it’s a good feeling to know they’re giving medical personnel the time and space to learn this important procedure. “You want to make your mistakes here instead of in surgery. And you feel free to explore here and learn. You need that room to grow. This is a devastating disease, but giving confidence to those who use this method can give confidence to the patient.”

Eric Butterman is an independent writer.

Learn about the latest trends in medical diagnostics at ASME’s Global Congress onNanoEngineering for Medicine and Biology.

This is a devastating disease, but giving confidence to those who use this method can give confidence to the patient.Prof. Kenji Shimada, Carnegie Mellon University

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