Zettai Shonen

Prostate cancer is the second leading cancer related cause of death as well as the number one most common form of cancer found in men. Most of them require surgery to remove the tumor and radiation therapy afterwards.

The radiation therapy is aimed at the place where the prostate used to be, also known as the prostate bed. The radiation therapy usually comes under the form of Intensity Modulated Radiation Therapy (IMRT). This technique works by focusing the radiation beams on the prostate bed while at the same time tries to leave the surrounding tissue and organs untouched. Doctors recommend that for this technique to be efficient the radiation beams should aim for the prostate bed only and to avoid the adjacent structures such as the bladder and rectum. But this is hard to achieve as the position of the prostate bed is subject to change as there are many factors that influence its position.

Researchers at Fox Chase Cancer Center have made a new study in which they reveal that in many cases IMRT does not cover 100 percent the prostate bed. Doctors try to compensate that by increasing the power or the period of exposure but in both cases patients receive too little treatment on the prostate bed or too much in the adjacent structures.

Tracy Klayton, M.D. presented a study that aims to examine the location and motion of the prostate bed during radiation therapy with IMRT and hat are the effects. In this study, Klayton studied 20 patients who were submitted to more than 600 IMRT sessions.
The machine that they choose to use is one of the most precise devices on the market. It is called the Calypso 4D Localization System and it uses three radiofrequency transponders which are implanted in the patients' prostate bed. This helps the doctors pinpoint exactly the position of the prostate bed before radiation therapy can begin each day. During the treatment Klayton noticed that the prostate bed was offset from the targeted area by more than 5 mm. This small offset can have serious consequences.
Thanks to the new device doctors are able to calibrate exactly the prostate bed wit the targeted area so that the treatment can be used at its maximum efficiency level.