Younger patients with brain metastases who underwent stereotactic radiosurgery alone demonstrated longer OS than those who underwent stereotactic radiosurgery in combination with whole-brain radiation therapy.
The omission of whole-brain radiation therapy (WBRT) did not increase risk for new brain metastases, researchers said.
Arjun Sahgal, MD, associate professor of radiation oncology at the University of Toronto and deputy chief of radiation oncology at Odette Cancer Center of Sunnybrook Health Sciences Centre in Toronto, and colleagues evaluated data from 389 patients enrolled on three randomized, controlled trials.
The researchers included 364 patients in their analysis; of them, 41% had a recursive partitioning analysis score of 1 and 60% had one brain metastasis. Nineteen percent of patients were aged 50 years or younger.
The patients received stereotactic radiosurgery alone (51%) or stereotactic radiosurgery plus WBRT.
Patients with one to four brain metastases, a recursive partitioning analysis score of 1 or 2, and a Karnofsky performance score of ≥70 were eligible.
OS served as the primary endpoint.
Overall, 86% of patients died during follow-up.
Patients who underwent stereotactic radiosurgery alone experienced longer median time to death (10 months vs. 8.2 months).
Local failure occurred in 21% of patients, and 44% had distant brain failure.
Patients assigned to stereotactic radiosurgery plus WBRT experienced longer median time to local failure (7.4 months vs. 6.6 months) and distant brain failure (6.5 months vs. 4.5 months).
Multivariable analyses indicated that treatment outcomes were significantly associated with age (P=.04), as stereotactic radiosurgery alone was associated with extended OS among patients aged ≤50 years. Researchers calculated HRs of 0.46 (95% CI, 0.24-0.90) for patients aged 35 years; 0.52 (95% CI, 0.29-0.92) for those aged 40 years; 0.58 (95% CI, 0.35-0.95) for those aged 45 years; and 0.64 (95% CI, 0.42-0.99) for those aged 50 years.
Patients aged ≥50 years who underwent stereotactic radiosurgery alone were more likely to have distant brain failure. In addition, multiple brain metastases were associated with a significantly increased risk of distant brain failure (HR=1.59; 95% CI, 1.14-2.2).
“WBRT may not be required for all patients with brain metastases, particularly younger patients, and stereotactic radiosurgery alone should be considered as the favored first-line therapeutic option,” Sahgal said in a press release. “The implications are significant, as it has been shown in other studies that WBRT is detrimental to short-term memory function and negatively impacts some aspects of patients’ quality of life.”
For more information:
Sahgal A. Abstract #LBA3. Presented at: 2013 ASTRO Annual Meeting; Sept. 22-25, 2013; Atlanta.
Disclosure: The researchers report no relevant financial disclosures.