By Dr. Mitchell Pincus
The American Cancer Society estimates that 29,412 men died from prostate cancer in 2008. Unfortunately, prostate cancer strikes African-American males at a higher rate than other demographics, as well as among those with a family history of prostate cancer. However, most experts agree that prostate cancer is treatable and highly curable if the disease is detected early.
Studies have demonstrated that radiation treatment – delivered externally and internally – is as effective in treating the disease as surgical removal of the prostate. Although there are side effects associated with radiation, patients who choose this treatment often cite the risks of surgery – most notably incontinence and impotence. Further, because radiation can be delivered in an outpatient setting, most men are able to experience their normal daily activities during treatment. However, like all treatment regimens, radiation delivery is not without its challenges.
One of the biggest issues doctors face in delivering external beam radiation to the prostate tumor is organ motion, a natural and commonly-occurring bodily function. Clinical studies have documented that organ motion is both unpredictable and variable. Each day the prostate may shift up to a centimeter and during treatment, it may shift several millimeters when a patient breathes or coughs. Although this may seem like a small distance, it can produce some big problems. Unfortunately, conventional methods to locate tumors do not allow doctors to identify the exact location of a tumor in real-time during radiation therapy.
Doctors take organ motion into consideration by delivering radiation to an area surrounding the prostate, in case the tumor moves. However, that can also result in the unintended irradiation of healthy tissue. If that tissue is the urinary tract or rectum, this accidental exposure may often lead to side-effects.
If a tumor can be effectively tracked during treatment, the radiation can be delivered more accurately. Knowing the exact location of the tumor, in real-time, allows doctors to deliver radiation only to the tumor and not the adjacent healthy tissue.
Nearly 100 medical centers throughout the country, including St. Luke’s Medical Center-Aurora in Milwaukee have adopted a revolutionary technology called the Calypso System. This device, which is also known as “GPS for the Body®”, enables physicians to determine the exact location of the prostate in realtime during radiation therapy. Armed with this information, radiation to the surrounding healthy tissue can be avoided and side effects can be minimized.
This technology is driven by three electromagnetic transponders, each the size of a grain of rice, which are permanently implanted within the patient’s prostate gland (the procedure is similar to that of a biopsy). The transponders send benign radio waves that allow physicians to precisely pinpoint the location of the prostate, even if it moves during treatment. If necessary, the physician can pause treatment and re-adjust the patient, thereby avoiding potential damage to the healthy tissue.
A few months ago, the results of a clinical study involving this technology were published in a medical journal. Researchers found that prostate cancer patients who were treated with radiation therapy and whose tumors were monitored by the Calypso System reported fewer bowel, rectal and urinary side effects than patients whose radiation treatments without GPS for the Body.
When treating the prostate, every millimeter matters. The Calypso System’s ability to track organ motion ensures that the radiation beam hits its target – and nothing else – for the duration of treatment. My patients who have undergone radiation accompanied by this technology find confidence and reassurance in knowing that we are using cutting-edge technology to not only eradicate their cancer, but to do it in such as way that maintains their high quality-of-life.
Dr. Mitchell Pincus is a practicing radiation oncologist at St. Luke’s Medical Center- Aurora. For an appointment, please call (414)649-6420. For more information on the Calypso System, please visit: www.calypsomedical.com.