Three-dimensional (3D) treatment planning refers to the use of software and
hardware tools to design and implement more accurate and conformal radiati
on therapy. This is a major advance in oncology that should lead to the red
uction of treatment-associated morbidity and facilitate safe dose escalatio
n for many tumor sites. This technology affords the incorporation of physio
logic and anatomic information into the treatment planning process, further
enhancing our ability to improve the therapeutic ratio. However, as with a
ny new technology, care must be taken when applying it in the clinic. The i
ntroduction of 3D planning presents new challenges to existing quality assu
rance systems. These need to be addressed to maintain patient safety. Based
on our experience with over 1,500 patients treated at Duke University, the
benefits, challenges, and hazards of routine 3D treatment planning are dis
cussed.