Latest Breakthrough in Prostate Cancer Treatment?
An internal medicine colleague of mine and I were eating lunch in the hospital cafeteria the other day and our discussion topic came to prostate cancer and high dose rate brachytherapy. He said that he read that a new Calypso System was the latest breakthrough in prostate cancer treatment and what was my take on it. I told him, “During the long course of external beam radiation treatment the prostate naturally moves due to respiration, gas in the rectum, etc. Likewise it is virtually impossible to get a human body in the exact same position every day, five days a week for eight to nine weeks.” This new technology is based on scientific principles very similar to that in global positioning satellite (GPS) devices. Three tiny devices are implanted in the prostate prior to external beam radiation. These devices, each about the size of a grain of rice, are tracking devices called beacon transponders. Then, during external beam radiation, the beacon transponders communicate with the Calypso System constantly so the external beam stays locked on to the target. I told him, “This is an expensive and late refinement to catch up with the inherent virtue of high dose rate brachytherapy for prostate cancer. Of course the prostate moves naturally, but with the high dose rate brachytherapy technique the treatment catheters are implanted in the prostate so they go wherever the prostate goes.” The prostate cancer is always on target. There is no need for a complicated tracking system. Further, the Calypso system still does not address the disadvantage of the external beam going through the normal pelvic structures to get to the walnut sized target. High dose rate brachytherapy treats the prostate cancer from inside out so normal tissue gets a minimal dose. After hearing all this, my colleague agreed that the Calypso system is an improvement but still short of the virtues of high dose rate brachytherapy for prostate cancer.