There has been a long-standing question about how to best use radiation to treat cancer that has spread to a person’s brain. Now, University of North Carolina Lineberger Comprehensive Cancer Center researchers say a new study has resolved a debate over the risks and benefits of adding whole-brain radiation treatment to targeted radiation for people with one to three brain metastases.
In an editorial in this week’s Journal of the American Medical Association, UNC Lineberger researchers evaluated findings of a multi-center study that compared two radiation strategies for 213 patients with one to three brain cancer metastases. The study found fewer cognitive side effects in patients treated with stereotactic radiosurgery – a more precise form of radiation that spares healthy brain tissue – compared to patients treated with stereotactic radiosurgery and whole-brain radiation. The combination radiation led to better control of the cancer in the brain, but did not add a survival advantage for patients.
Based on the study findings, UNC Lineberger researchers said there was “little role” for adding whole-brain radiation for patients with one to three cancerous spots in the brain.
“At the end of the day, if you’re not going to improve patients’ survival, you certainly don’t want to worsen their quality of life while they’re interacting with their family and doing the things they want to do, knowing that they have a terminal disease,” said UNC Lineberger member Carey Anders, MD, a medical oncologist and associate professor in the UNC School of Medicine.
Anders co-authored the editorial with Orit Kaidar-Person, MD, a clinical fellow in the UNC School of Medicine Department of Radiation Oncology, and Timothy M. Zagar, MD, a UNC Lineberger member and assistant professor in the UNC School of Medicine Department of Radiation Oncology.
“Patients who got whole-brain radiotherapy had better intracranial control for a longer period of time, but that came at a cost of worse quality of life and worse neurocognition during the time that they were progression free, and it did not affect survival,” Anders said of the study findings.
In further support of their position, the authors cited the American Society of Radiation Oncology's 2014 recommendation that whole-brain radiation should not be routinely added to stereotactic radiosurgery for patients with a limited number of brain metastasis, and noted that many radiation oncologists in the modern era consider stereotactic surgery to be standard of care for patients with less than three brain metastasis.
Yet Zagar said that for some, the fact that whole-brain radiation better controls the cancer, but does not increase survival, goes against conventional wisdom.
“It makes a lot of sense that if you prevent cancer from coming back in the brain, you’d see improvements in survival, but truth be told, the data do not necessarily demonstrate that,” he said.
The UNC Lineberger researchers cautioned against overgeneralizing the findings. They concluded that the study resolves the debate for patients with three or fewer brain metastases of a limited size, but they argued that there is still a role for whole-brain radiation for patients with larger tumors and larger numbers of brain metastases.
“If you have many lesions in the brain, whole-brain radiotherapy is the standard of care,” Anders said. “This particular trial focused on patients who had three lesions or less.”