Hypofractionated (HF) whole breast irradiation (WBI) is effective for many patients with early-stage breast cancer, according to new evidence-based guidelines issued by the American Society for Radiation Oncology (ASTRO).
The guidelines, published online in the International Journal of Radiation Oncology∙Biology∙Physics, the official ASTRO journal, define appropriate fractionation of WBI.
WBI following breast-conserving surgery has been shown to lower the risk of tumor recurrence and improve survival. Conventionally fractionated (CF) radiation involves daily treatments for up to 7 weeks and so can be costly and inconvenient for the patient. HF-WBI, in contrast, uses a higher dose of radiation per treatment but fewer total treatments so patients can typically finish radiation in 4 weeks or less. Several studies have found little difference in local control and survival outcomes for selected patients treated with CF-WBI or HF-WBI.
The ASTRO task force concluded that HF-WBI is just as effective as CF-WBI for patients with early-stage breast cancer who meet certain criteria, including:
- Age ≥50 years
- Stage T1-2 N0
- Not receiving chemotherapy
- Relatively uniform delivery of the radiation dose
- Ability to exclude the heart from the path of the radiation beam
There was insufficient evidence for the panel to reach a consensus for or against the use of HF-WBI for patients not meeting these criteria.
“Widespread adoption of HF-WBI for appropriately selected patients has the potential to enhance the convenience of treatment and lower the costs of WBI,” said Benjamin D. Smith, lead author of the guidelines and a radiation oncologist at the University of Texas M.D. Anderson Cancer Center in Houston. For patients who do not meet the criteria, he added, HF-WBI can be considered an option but further research is needed.