In this study the investigator would like to better understand the use of high-dose rate (HDR) brachytherapy to target only recurrent prostate cancer that can be seen by AXUMIN PET scan. The use of HDR brachytherapy for prostate cancer is not new, but it is a more recent advancement to use it to treat only what can be seen instead of the whole prostate.
The purpose of this study is to learn more about what effects the use of high-dose-rate (HDR) brachytherapy on prostate cancer recurrence, seen by AXUMIN PET scan, has on prostate cancer.