This article is more than 5 years old. Information may no longer be current.
Stereotactic radiosurgery comparable to surgical resection for local control of brain metastases
Stereotactic radiosurgery appeared comparable to surgical resection for controlling local brain metastases, according to an exploratory analysis of a randomized phase 3 trial.
Radiosurgery demonstrated an early benefit that decreased over time.
The analysis was the largest direct comparison of the two treatment modalities, according to researchers.
“Surgery is still a vital part of treatment for some patients with brain metastases,” Stephanie Weiss, MD, FASTRO, chief of the division of neurological oncology, associate professor in the department of radiation oncology, and director of the radiation oncology residency and fellowship training program at Fox Chase Cancer Center, told HemOnc Today. “However, the current analysis can inform decision-making for that large population of patients for whom there is no definitive indication for surgery, but for whom there remains a great deal of debate at brain tumor boards regarding how best to treat.”
In the EORTC 22952-26001 trial, researchers randomly assigned patients with one to three brain metastases to whole-brain radiotherapy or observation, either after complete surgical resection or prior to stereotactic radiosurgery.
In the exploratory analysis, Weiss and colleagues evaluated 268 patients (66.4% men; median age, 60.7 years [range, 26.9-81.1]) from the trial, including 154 (57.5%) who received stereotactic radiosurgery and 114 (42.5%) who underwent surgical resection.
The most common primary tumors were lung cancer (59.1% stereotactic radiosurgery vs. 58.8% surgical resection), breast cancer (11.7% vs. 8.8%), kidney cancer (11% vs. 7.9%), colorectal cancer (6.5% vs. 13.2%) and melanoma (5.8% vs. 2.6%).
The most common metastases sites were parietal (39.6% stereotactic radiosurgery vs. 18.4% surgical resection), frontal (27.9% vs. 36.8%), occipital (12.3% vs. 12.3%), posterior fossa (7.8% vs. 26.3%) and temporal (7.1% vs. 4.4%).
All patients had one to two brain metastases, with tumor diameter no greater than 4 cm.
Patients were stratified according to local intervention — surgical resection vs. stereotactic radiosurgery — and were followed for a median 39.9 months (range, 26-1,982).
Local recurrence of treated metastatic lesions served as the study’s primary endpoint.
Researchers calculated the cumulative incidence of local recurrence based on intervention, and they conducted competing-risk regression to adjust for prognostic factors and competing mortality risk.
Patients who underwent stereotactic radiosurgery appeared more likely than those who underwent surgical resection to have larger metastases (median, 28 mm [range, 10-40] vs. 20 mm [range, 4-40]; P < .001) and one brain metastasis (112 [98.2%] vs. 114 [74%]; P < .001). Adjusted models revealed similar rates of local recurrence between groups (HR = 1.15; 95% CI, 0.72-1.83).
In an analysis stratified by time interval, the surgical resection group had a significantly higher risk for early local recurrence (0-3 months) than the stereotactic radiosurgery group (HR = 5.94; 95% CI, 1.72-20.45). The risk was lower at 3 to 6 months (HR = 1.37; 95% CI, 0.64-2.9), and at 6 to 9 months (HR = 0.75; 95% CI, 0.28-2). At 9 months and beyond, the surgical resection group had a lower risk for local recurrence (HR = 0.36; 95% CI, 0.14-0.93).
Weiss said it is not entirely clear why the surgical resection group had a significantly higher risk for early local recurrence, Weiss said.
“[Although] our study can’t definitively answer this question, I would speculate that the different patterns for local recurrence after surgery vs. radiosurgery reflect the fundamentally different strategies for ‘tumor ablation’ they employ,” Weiss told HemOnc Today. “For surgery, we physically resect malignant cells out of the body, but there remains a substantial risk of leaving potentially microscopic disease behind. To me, this suggests that a propensity for early relapse that tapers off over time reflects an ‘all-or-nothing’ phenomenon; in any given case, surgery will either remove either all the cells or will not.” – by Jennifer Byrne
For more information:
Stephanie Weiss, MD, FASTRO, can be reached at Fox Chase Cancer Center, Department of Radiation Oncology, 333 Cottman Ave., Philadelphia, PA 19111; email: stephanie.weiss@fccc.edu.
Disclosures : Weiss reports no relevant disclosures. Please see the study for all authors’ relevant financial disclosures.