Women with breast cancer often find several weeks of daily radiation treatment difficult but a new study shows that a type that performed over a much shorter period may work just as well for some women.

In the U.S., women who have early stage breast cancer traditionally have been treated with conventional radiation, which involves smaller doses given daily for a long period of time (usually 7 weeks) as compared to a method known as whole-breast irradiation, which consists of higher doses over a shorter treatment period (4 weeks).

This is the practice even though large randomized trials from Canada and the U.K. have established that the shorter type of radiation is safe and effective for nearly all patients with early-stage breast cancer, researchers from M.D. Anderson Cancer Center say.

The shorter form of radiation has been found to carry fewer side effects, as well as less post-radiation fatigue, but only one-third of women that fit the American Society of Radiation Oncology criteria actually receive it, in part because of a concern that this type of treatment won’t work as well for American women, who tend to weigh more, the researchers say.

For this study, 287 patients with early stage breast cancer were divided into two groups, one which received the conventional treatment and the other that were given the shorter term type. In addition, all of the patients received a “boost dose,” an additional treatment targeting the tumor bed with a higher dose, which has not been systematically analyzed in previous studies.

All participants were at least 40 years of age, had been diagnosed with early stage breast cancer, meaning they had small tumors that had not spread, and had undergone mastectomies. In addition, 76 of the study participants were overweight or obese. Assessments were performed at baseline, six months, and at one, two and three years following treatment, the researchers say.

The researchers found no difference between the groups of women in terms of safety or effectiveness, so they say this study, which appears in Cancer, should be used to add to recommendation that women with early stage breast cancer should receive the shorter course of treatment.