New guideline: Hypofractionated radiation therapy offers cost advantage, patient convenience
External beam radiation therapy (EBRT) is a standard option for the initial management of men with localized prostate cancer, and a new guideline states that hypofractionation of radiation treatment confers benefits for cost and convenience.
Developed collaboratively by the American Society for Radiation Oncology, American Society of Clinical Oncology and American Urological Association, the guideline addresses key questions on appropriate indications and dose fractionation, as well as technical issues involving dose constraints, treatment volumes, and use of image-guided and intensity-modulated radiation therapy. [J Urol 2018;doi:10.1016/j.juro.2018.10.001]
Hypofractionation is categorized as moderate (fraction size, 240–340 cGy) and ultra (fraction size, ≥500 cGy), whereas conventional fractionation is defined as a fraction size of 180–200 cGy. The evidence-based recommendations apply to men who require or prefer treatment over active surveillance and who have opted for EBRT as opposed to other treatment options.
Moderate hypofractionation is recommended to patients across risk groups who choose EBRT, as this approach delivers prostate cancer control outcomes and late toxicity rates similar to those of conventional fractionation.
“Although there is limited follow-up beyond 5 years in completed trials, the task force nonetheless concluded that the existing evidentiary base is sufficiently robust to justify routine use of moderate hypofractionation,” says study author Dr Howard Sandler from the Cedars-Sinai Medical Center in Los Angeles, California, US.
For low- and intermediate-risk prostate cancer, the guideline conditionally recommends ultrahypofractionated radiation. However, it is strongly encouraged that intermediate-risk patients be treated on a clinical trial or multi-institutional registry.
For high-risk patients, the guideline likewise provides a conditional recommendation advising against routine use of ultrahypofractionated EBRT.
When undertaking either moderately or ultrahypofractionated EBRT, recommendations state that meticulous attention be given to the technical aspects of treatment planning and delivery. Image-guided radiation therapy should be used, whereas nonmodulated three-dimensional conformal techniques be avoided.
According to Sandler, the conditional recommendations pertaining to ultrahypofractionation highlight the importance of shared decision-making between clinicians and patients in such a setting.
“The decision to use ultrahypofractionated radiation therapy should follow a detailed discussion of the uncertainties in the risk-benefit balance for this treatment approach and should be informed at all stages by the patient’s values and preferences,” he adds.