New system targets prostate cancer cells with little to no collateral damage

Published: Thursday, Aug. 8 2013 10:12 p.m. MDT

Dr. Jonathan Tward, left, a radiation oncologist at the Huntsman Cancer Institute, observes as patient Hugh Barlow is being prepared for his treatment Thursday, Aug. 1, 2013. Doctors are using the Clarity guidance system to target and kill prostate cancer.

Joe DeLuca, Deseret News

Enlarge photo»

SALT LAKE CITY — Utah doctors are using a new tracking technology to precisely target and kill prostate cancer.

And it’s completely noninvasive.

The Clarity guidance system uses ultrasound, an imaging and diagnostic tool, like a targeting pilot that takes the cancer treatment from point A precisely to point B in the patient.

For several years, oncologists at the Huntsman Cancer Institute have been using the Calypso system to target prostate cancer. Oncologists implant beacons inside the body. When Calypso was activated, it sent a message to the tiny beacons and that allowed doctors to target the cancer with amazing accuracy, while avoiding surrounding tissue.

While that system has worked well, it is not ideal for 50 percent of the patients who may be overweight, on blood thinners or have implants — because the tracking isn’t as reliable.

With Clarity, because it’s noninvasive, it doesn’t matter if there are metals in the body or if someone is slightly overweight.

"We're able to watch the motion of the prostate in real time, and if this prostate moves more than 2 millimeters for more than two seconds, the system will alarm and we'll readjust the patient to make sure we are spot on each time,” said Dr. Jonathan Tward, a radiation oncologist at the Huntsman Cancer Institute.

For Tward and his colleagues, this precision killing of the cancer clusters is extremely effective. Because they don’t have to account for the prostate moving around, the treatment field has shrunk.

“There’s a far less probability that the bladder or the bowel, which is what one is concerned about getting collateral damage, will in fact be damaged,” Tward said.

Traditionally, patients go in for nine weeks of treatment, but that’s partially because doctors have to allow the normal tissue to slowly heal. Currently, the standard is about 44 treatments.

“Because we can get so accurate now, we can do much more targeted therapy in as few as five treatments,” Tward said.

The procedure is also less stressful on patients. "I've been surprised at how well I've done through this whole process because you go into something and don't know what it's going to be,” Hugh Barlow said.

Barlow was diagnosed with prostate cancer about four years ago. His doctors suggested surgery, but he didn’t feel comfortable with that. He got a second opinion and was put in touch with an oncologist at the Huntsman Cancer Institute who suggested they just watch and see how the cancer develops.

In December, his PSA levels were up. Prostate-specific antigen is a protein produced by the prostate gland. The higher the level, the more likely the man has prostate cancer. A biopsy was done and indicated his cancer had progressed.

After a lengthy meeting with Tward, he said he felt comfortable and confident this unique noninvasive technique to kill cancer cells would work with little or no collateral damage to surrounding healthy tissue, especially his bladder and colon.

The majority of patients will report minimal to no long-term complications of this therapy.

“In terms of significantly annoying bowel or bladder problems after radiation therapy, we’re about one in 20 people who will have something that they really wished they didn’t have,” Tward said. “Most of other people have none or something so minor that they don’t have to adapt their lifestyle.”

Oncologists appear to be spiking the cure numbers for prostate cancer: a cure rate that now stands at 90 percent to 95 percent.

“We're getting quite good at making prostate cancer go away,” Tward said.

Early detection is key in treating most cancers. A panel of experts at the National Cancer Institute recently said it wanted to change the way some types of cancers are diagnosed and treated. They say not all cancers are alike and not all cancers are deadly.

“So now we are starting to identify cancers that are so early that they may not need treatment,” Tward said.

Tward said a good example of a cancer being overtreated is prostate cancer.

“We have a large number here (at Huntsman Cancer Institute) who we merely observe closely, and we will definitely be on top of their cancer if it ever progresses,” Tward said.

He said new treatments have decreased the side effects of therapy, while at the same time increasing the efficacy.

Patients need to think of having cancer not as a terminal disease, but sometimes like a chronic disease, such as diabetes or heart disease, he said.

“There might be some consequence,” Tward said. “We might have to put you on certain medications or whatnot, but you can definitely live a full life and have cancer at the same time.”

Contributing: Viviane Vo-Duc

Email: eyeates@deseretnews.com

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