Predictive biomarkers for prostate brachytherapy—not there yet

Brachytherapy has been used for the treatment of prostate cancer for nearly 100 years. Low dose rate brachytherapy, the permanent placement of radioactive seeds (e.g., Iodine-125 or Pallidium-103) within the prostate, is an effective treatment for men with clinically localized low-risk prostate cancer. Brachytherapy can also be delivered by temporarily inserting high energy radioactive isotopes (e.g., Iridium-192) into the prostate. This technique is referred to as high dose-rate brachytherapy. The ability of brachytherapy to directly deliver radiation within the prostate while limiting the dose delivered to surrounding normal tissues is a significant advantage of this treatment (1).