Radiation therapy is subdivided into external (tele) and internal (brachy) therapy. Brachytherapy (brachy=Greek, short) consists of applying the radioactive source directly into or through the tumor. Conversely, teletherapy, (tele=Greek, long) consists of delivering the radiation externally using a linear accelerator. The advantages of brachytherapy include the high dose local irradiation of the diseased tissue while sparing the contiguous normal tissue.

One form of brachytherapy of the prostate is the implantation of low radioactive, sealed sources, known as seeds, into the prostate. An urologist implants these small, low radioactive sources using needles through the perineum. This procedure is performed under ultrasound guidance and can be performed ambulatory in one day.

 

 

 

 

 

 

 

 

A seed has a length of 4.5 mm and a diameter of 0.8 mm 

 

Depending on the diagnosis, brachytherapy can be performed as monotherapy (single therapy) or in combination with either external beam radiation therapy or hormonal treatment. Usually, the isotope I-125 is used. For permanent interstitial brachytherapy, IBt Bebig offers the IsoSeed I-125 which contains low activity I-125.