Brachytherapy for Prostate Cancer: An Overview

Brachytherapy (BT) is defined by the proximity of radiation source placement either inside or adjacent to the tumor or volume requiring treatment. For prostate cancer, BT is divided into low dose rate (LDR) permanent seed implantation and high dose rate (HDR) temporary source implantation. BT may be used together with external beam radiation therapy (EBRT) as a "boost." LDR-BT alone is readily acknowledged as a standard option in low-risk prostate cancer (PCa) by many health organizations, based on prospective evidence. LDR-BT boost is similarly an acceptable first-line treatment option in certain intermediate-risk and most high-risk cancer patients. HDR-BT monotherapy may be used as a first-line treatment option in certain low- and intermediate-risk PCa patients. Studies of HDR-BT monotherapy have encouraging results in terms of biochemical control, patient survival, and treatment toxicity; however, compared to studies of LDR-BT and EBRT, HDR-BT monotherapy studies have a relatively shorter follow-up time and fewer patients. HDR-BT boost is now a relatively well-established treatment modality for certain intermediate-risk and high-risk PCa, based on prospective evidence. Finally, androgen deprivation therapy is used in addition to either form of BT in certain intermediate- and high-risk patients.