Physics Bucharest 2017

Higher PSA and Gleason score are associated with an increased risk of extra- capsular extension of prostate cancer

100% isodose line (yellow)

Prostate contour (red)

In I-125 brachytherapy the dose (145Gy) is prescribed to the 100% isodose which should encompass the prostate with a 3mm margin. Any extra-capsular spread beyond the prostate will not be encompassed and risks treatment failure so I-125 alone is not recommended with higher PSA or Gleason scores