GPS for the Body: Pinpointing cancer

"I’m gonna be fine,” Linton Young of San Mateo repeatedly told himself when he found out he had prostate cancer last year.

Because of a breakthrough technology in radiation therapy with which doctors treated him, Young had even more reason to believe this to be true.

The Calypso 4D Localization System allows radiologists to more accurately target cancer cells during radiation treatment, protecting healthy tissue from exposure during radiation treatments. First developed by researchers at the University of Washington five years ago, Calypso has been used in dozens of successful cancer treatments at Mills Peninsula Hospital of San Mateo over the past year.

Appropriately nicknamed "GPS for the Body,” the technology functions with the help of three electromagnetic transponders, known as beacons. When these tiny transponders, each the size of a grain of rice, are implanted into the prostate, they can track the exact location of the prostate — and the cancer.

Clinicians use the data retrieved by the beacons to monitor movement of the prostate and focus the radiation during treatment. With this technology, radiation can be administered in a higher dosage without the possibility of affecting healthy tissue.

"The problem is, the prostate can move on the radiation table,” said Stephen A. Weller, a radiation oncologist at Mills-Peninsula Hospital. Without Calypso, it is impossible to determine if the prostate moves during radiation therapy. If it does move, the radiation may destroy healthy tissue cells instead, causing hemorrhoids, bleeding and increased urinary frequency and burning.

"With this system, we can be certain of exactly where the prostate is,” said Weller, "even if the prostate moves a few millimeters.”

Dr. Stephen Kurtzman of Mills was the first to suggest the treatment to Young.

"None of the procedure was painful,” said 78-year-old Young. "It’s not very intrusive.” Young experienced no severe side effects as a result of the Calypso-assisted radiation therapy.

There are no downfalls or side effects specific to the new technology, said Weller. The only discomfort that might be felt is during the insertion of the beacons. "It is similar to having a biopsy with needles,” Weller said of the implantation. "Once it’s in, there is no feeling whatsoever. It really is totally harmless.”

The only disappointment Young had with radiation therapy was the interruption in his daily workout routine.

"I’m a veteran so I know how to exercise,” he said, regretting that he had to stop exercising during treatments.

One month after his final treatment, Young was well on his way to recovery and back to his usual workout routine.

The new technology has already had its national debut and is currently used by both major medical centers and private facilities across the United States.

Weller is confident of Calypso’s future success for other types of cancer.

"The same method can be used in locating tumors in different parts of the body — the breast, the throat, the lung, the mouth,” Weller said. "This is going to be developed for other tumor areas in the near future.”