Boost dose reduces recurrence in high-risk DCIS

Reduce the boost dose?

A radiation oncologist who was not involved in this study said that, while the results confirm a benefit of boost dose for patients with non–low-risk DCIS, the doses used in the BIG-3-07 study may be higher than needed to achieve a protective effect.

“Here in America, we usually give 10 Gy in five fractions, and, in many countries, actually, it’s 10 Gy in five fractions, although a few European centers give 16 Gy in eight fractions,” said Alphose Taghian, MD, of Massachusetts General Hospital in Boston.

“I personally only give 10 Gy in five fractions. I am not under the impression that 16 Gy in eight fractions will give better results. The local failure rate is so low, it’s likely that 10 Gy will do the job,” Dr. Taghian said in an interview.

Dr. Taghian noted that raising the dose to 16 Gy increases the risk of fibrosis, as seen in the BIG-3-07 trial.

Nonetheless, the trial demonstrates the benefit of radiation boost dose in patients with high-risk DCIS, he said, adding that the local recurrence-free benefit curves may separate further with longer follow-up.

The study was sponsored by the Trans Tasman Radiation Oncology Group. Dr. Chua and Dr. Taghian reported no conflicts of interest.