Whole Breast Radiation Guidelines Updated to Expand Options for Cancer Patients

The American Society for Radiation Oncology (ASTRO) issued new guidelines for the use of whole-breast radiation therapy for breast cancer patients. The new guideline expands the patient population recommended to receive an accelerated treatment known as hypofractionated therapy. This means that patients receive larger doses of radiation across fewer treatment sessions, completing treatment in three to four weeks, compared to five to seven weeks with conventional therapy.

“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.

– Benjamin Smith, MD, Co-chair of the guideline task force, and associate professor of radiation oncology, University of Texas MD Anderson Cancer Center

This change in the guideline now allows for hypofractionatedeatment for breast cancer patients regardless of age, tumor stage and whether they have received chemotherapy.

Despite the expanded guidelines, many patients eligible for accelerated treatment are still not receiving it. One reason radiation specialists are staying with the conventional whole-breast radiation schedule is a concern about side effects when compressing the same radiation dose in to a three to five week schedule. Conversely, a recent JAMA Oncology study found that women on a hypofractionated radiation schedule actually had fewer side effects than women on a conventional radiation schedule.

“47% of the hypofractionated group had one or more side effects compared to 78% of the conventional group.”

– JAMA Oncology

As additional studies like these are conducted and discussed, the goal is that a larger population of breast cancer patients will start receiving this treatment.

A hypofractionated whole-breast radiation schedule is appealing to physicians and patients alike. A shorter treatment schedule allows for easier scheduling, less time away from work and lower treatment costs.

“Hypofractionated radiation therapy offers patients a more convenient and lower cost option for their treatment without compromising the likelihood that their cancer will return or increasing their risk of side effects,”

– Reshma Jagsi, M.D., D.Phil., Co-chair of the task force and a professor of radiation oncology at the University of Michigan in Ann Arbor

Delivery and Dosing of WBI

  • Treatment decisions, including decisions between hypofractionated and conventional approaches, should be individualized to each patient and shared between the patient and their physician.
  • For women with invasive breast cancer receiving WBI with or without inclusion of the low axilla, the preferred dose-fractionation scheme is hypofractionated WBI to a dose of 4000 Centigray (cGy) in 15 fractions or 4250 cGy in 16 fractions.
  • The decision to offer hypofractionated therapy should be independent of the following factors: tumor grade; whether the tumor is in the left or right breast; prior chemotherapy; prior or concurrent trastuzumab or endocrine therapy; and breast size, provided that homogenous dosing can be achieved.

New whole breast radiation guidelines deliver clinical direction for dosing, planning, and administering WBI. With all the data supporting accelerated treatment, the hope is that this guideline pushes providers to advise their patients on options including hypofractionation for whole breast radiation.