IGRT in Prostate Cancer: Focus on BAT Ultrasound

There are several rationales for the use of daily image-guided radiation therapy (IGRT) in the management of prostate cancer. The ability to consistently and reprodu-cibly deliver the prescribed dose of radiation to the target is the most obvious reason. Another reason is the ability to safely escalate radiation dose. The first reports illustrating this dose response appeared in 1995, and since that time, multiple single-institution prospective, retrospective, and phase III randomized prospective trials have confirmed this phenomenon in prostate cancer. These studies have consistently demonstrated an improvement in biochemical control as an increasing dose of radiation is delivered to the prostate (1,3,4). Finally, IGRT allows for the limiting of dose to adjacent critical structures and the reduction of early and late complications. Dose-volume effects have been described in the literature for both the bladder and rectum (5,6).