ASTRO Guideline Recommends Larger Doses of Radiation, Fewer Sessions

ASTRO Guideline Recommends Larger Doses of Radiation, Fewer Sessions

A new guideline for treating breast cancer patients with whole breast irradiation recommends that most patients receive an accelerated treatment, known as hypofractioned therapy, instead of the conventional one.

This means that patients will receive larger doses of radiation delivered across fewer treatment sessions, completing treatment in three to four weeks, instead of the five to seven weeks that conventional therapy requires.

Patients will have “more time with family, less time away from work and lower treatment costs” Reshma Jagsi, MD, said in a press release. Jagsi is co-chair of the task force that compiled the guideline and a professor of radiation oncology at the University of Michigan in Ann Arbor.

The guideline, “Radiation therapy for the whole breast: Executive summary of an American Society for Radiation Oncology (ASTRO) evidence-based guideline,” was developed by the American Society for Radiation Oncology (ASTRO), and published in the journal Practical Radiation Oncology.

Whole breast irradiation (WBI) is the most frequently used type of radiation for treating tumors in the breast. With the approach known as hypofractionated WBI, patients are given larger doses of radiation in fewer treatment sessions.

While studies are increasingly supporting the accelerated treatment, experts say that many patients eligible for hypofractionated WBI are not receiving it. So, ASTRO researchers developed a new guideline to replace the whole breast irradiation guideline set in 2011.

The new guideline covers clinical guidance for dosing, planning and delivering WBI, and the use of the option of an additional “boost” of radiation after the course of therapy is complete.

“Previously, accelerated treatment was recommended only for certain patients, including older patients and those with less advanced disease, but recent long-term results from several large trials strongly support the safety and efficacy of accelerated treatment for most breast cancer patients,” said Benjamin Smith, MD, co-chair of the guideline task force and an associate professor of radiation oncology at the University of Texas MD Anderson Cancer Center in Houston. “Conventional therapy does not provide an incremental benefit in either tumor control or side effects compared to hypofractionated WBI.”

One of the key recommendations is that treatment decisions, including the choice between hypofractionated and conventional therapy, should be individualized and the decisions shared between patients and their physicians.

According to the new guideline, the decision to use hypofractionated WBI should not depend on whether the tumor is in the left or right breast, whether the patient received prior chemotherapy, is receiving Herceptin (trastuzumab) or endocrine therapy at the time of treatment, or breast size, as long as dosing can be distributed evenly.

The decision also may be independent of hormone receptor status, age, HER2 receptor status, and surgical margin. (Surgical margin is the rim of normal tissue surrounding a tumor, which is removed along with the tumor during surgery.)

“We hope that this guideline encourages providers to counsel their patients on options including hypofractionation,” Jagsi said.