What are the seeds made of and how long do they work for?
The seeds are small pellets of titanium (4.5mm long x 0.8mm diameter) that contain the radioactive isotope Iodine-125. The half–life of radioactive Iodine-125 is approximately 60 days. This means that most of the radiation is released from the seeds in the first three months, though they continue to emit a small amount of radiation for a further 9 months. After this time they remain in your prostate but are effectively non-radioactive.
