Ryan M Shute, Rifaquat Rahman, Shyam Tanguturi, Paul J Catalano, Daphne A Haas-Kogan, Patrick Y Wen, David Meredith, Wenya Linda Bi, Camille Verry, Jeffrey P Guenette, Nayan Lamba, Ayal A Aizer
Peripherally hyperenhancing brain metastases represent a distinct radiographic entity associated with renal primaries, edema, and neurologic symptomatology, with implications for surgical management and target delineation during stereotactic radiation. Definitive treatment seems to mitigate the aggressive nature of such tumors.
PURPOSE: Select brain metastases display peripheral hyperenhancement at the tumor-brain interface, constituting a unique radiographic entity. However, the incidence, associated clinical characteristics, pathologic correlates, and longer-term outcomes associated with this phenomenon remain largely unknown. Here, we characterize peripherally hyperenhancing brain metastases to inform clinical management.
METHODS: We identified 922 patients with 2790 newly-diagnosed brain metastases between 2009 and 2022 managed with brain-directed radiation at Brigham and Women's Hospital/Dana-Farber Cancer Institute. Peripheral hyperenhancement was defined as visualized contrast uptake at the periphery of the tumor exceeding background enhancement of the metastasis. Peripheral hyperenhancement was assessed at both per-patient and per-metastasis levels. Predictors and outcomes associated with peripherally hyperenhancing brain metastases were assessed using multivariable logistic and Fine-Gray models, respectively.
RESULTS: In total, 137 patients (15%) and 176 metastases (6%) demonstrated peripheral hyperenhancement. Pathologically, peripherally hyperenhancing metastases displayed tumor cells infiltrating brain parenchyma. Patients with peripheral hyperenhancement were more likely to present with neurologic symptoms (84% vs. 60%, p < 0.001) and seizures (20% vs. 12%, p = 0.008). Renal primaries (vs. the reference of non-small cell lung cancer, OR 2.54 [95% CI 1.19-5.45], p = 0.02) and larger metastasis size (OR 1.03 per 1 mm increase [95% CI 1.02-1.04], p < 0.001) were associated with peripheral hyperenhancement. Peripheral hyperenhancement was not associated with survival-based, recurrence-based, or other time-to-event outcomes after initial management.
CONCLUSION: Peripherally hyperenhancing brain metastases represent a distinct radiographic entity associated with renal primaries, edema, and neurologic symptomatology, with implications for surgical management and target delineation during stereotactic radiation. Definitive treatment seems to mitigate the aggressive nature of such tumors.