The rush to judgment: Does the evidence support the enthusiasm over three-dimensional conformal radiation therapy and dose escalation in the treatment of prostate cancer?

Purpose: To discuss the assumptions behind and current clinical evidence on three-dimensional conformal radiation therapy (3D-CRT) and dose escalation in the treatment of prostate cancer. Methods: We first define 3D-CRT in comparison to standard radiation therapy and discuss the assumptions on which the technology of 3D-CRT and dose esc alation are based. We then examine the evidence on the benefits and limitat ions from the current most commonly cited studies on dose-escalation trials to treat prostate cancer. Results: The assumption that 3D-CRT can provide a tighter margin around the tumor area to allow for dose escalation is not yet proven by studies that show continual difficulty in defining the planning treatment volume because of extrinsic and intrinsic difficulties, such as imaging variabilities and patient and organ movement. Current short-term dose-escalation studies on the use of 3D-CRT to treat prostate cancer are limited in their ability to prove that increasing dose improves survival and does not incur potential l ong-term complications to normal tissue. Conclusion: Although 3D-CRT is a promising technology that many radiation o ncologists and clinics are quickly adopting to treat such tumors as prostat e cancer, the long-term evidence on the benefits and limitations of this te chnology is still lacking. Until we have solid long-term evidence on the tr ue clinical potential of this new technology, let us not rush to judgment, but exercise caution, diligence, and thoughtfulness in using this new techn ology to treat our patients. (C) 2001 Elsevier Science Inc.