ABSTRACT
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).
