Hypofractionated Radiation Acceptable for Localized Prostate Cancer

A new study supports the use of shortened courses of radiation therapy (RT) for early-stage prostate cancer (PC).

Researchers at the University of Ottawa (Canada), Cedars-Sinai Medical Center (Los Angeles, CA, USA), Vanderbilt University Medical Center (VUMC; Nashville, TN, USA), and other institutions participating in a new task force convened by the American Society for Radiation Oncology (ASTRO) conducted a systematic literature review to address key questions and develop an evidence-based guideline for dose-fractionation RT for early-stage PC.

Among the issues discussed were technical aspects, including normal tissue dose constraints, treatment volumes, and use of image guided RT (IMRT) and intensity modulated RT (IMRT). Based on high-quality evidence, a strong consensus was reached to offer moderate hypofractionation across risk groups to patients choosing external beam RT (EBRT), and recommended ultrahypofractionated RT for low- and intermediate-risk PC. For high-risk patients, the routine use of ultrahypofractionated EBRT was not recommended. The study was published on October 11, 2018, in Practical Radiation Oncology.

“These recommendations are intended to provide guidance on moderate hypofractionation and ultrahypofractionation for localized prostate cancer. Men who opt to receive hypofractionated radiation therapy will be able to receive a shorter course of treatment,” concluded lead author Scott Morgan, MD, of the University of Ottawa, and colleagues. “The limits in the current evidentiary base, especially for ultrahypofractionation, highlight the imperative to support large-scale randomized clinical trials and underscore the importance of shared decision making between clinicians and patients.”

RT fractionation is defined as a fraction size of 180 to 200 cGy. Hypofractionation is subdivided into moderate hypofractionation (240-340 cGy) and ultrahypofractionation (a fraction size higher 500 cGy). These pragmatic definitions reflect two distinct approaches to hypofractionation that have emerged in clinical practice. The fraction size gap created (i.e., the gap from 340 cGy and 500 cGy) represents a little-studied range.

Related Links:
University of Ottawa
Cedars-Sinai Medical Center
Vanderbilt University Medical Center