BMET-11SURGICAL RESECTION OF CEREBRAL METASTASES LEADS TO FASTER RESOLUTION OF PERI-TUMORAL EDEMA: A QUANTITATIVE ANALYSIS

Abstract

BACKGROUND: Surgical resection and stereotactic-radiosurgery (SRS) are valid treatment options for selected patients with brain-metastases. The desired rate of resolution of the tumor-associated edema may play a role in the decision making process. However, the dynamics of edema resolution with each modality has not been well characterized. METHODS: Of 646 patients treated at our center for brain metastases between 2010-2014, we retrospectively identified 70 patients (100 metastases) who underwent either surgery or SRS for brain metastasis, and had sufficient clinical data, and radiological follow-up to be included in this study. Individual volumetric measurement of the tumor and edema before, and three months after treatment, was performed. RESULTS: Forty-six surgical cases were compared to 54 cases treated with SRS. As expected, the volume of the tumor and surrounding edema were significantly higher in the surgical group compared to SRS. However, resolution of edema was significantly superior in the surgical group (p < 0.0001). After a matching process based on the propensity of a patient to receive SRS, a nested cohort of 40 patients was analyzed (mean-maximal diameter:21.5mm vs. 18.8mm for surgery and SRS, respectively). At diagnosis, edema volume, but not tumor volume was significantly higher in the surgical group. Three months after treatment, the resolution of edema tended to be much more prominent in the surgical group (74.2% vs.18.8% improvement, p = 0.1). Steroid consumption was significantly higher in the SRS group (p = 0.02). No difference in the incidence of new neurological deficits after treatment was found between the groups. CONCLUSIONS: Resolution of tumor-associated edema in medium sized brain metastases tended to be more prominent after surgical resection compared to SRS. Irradiated patients required a significantly higher dose of steroids. Accordingly, when both treatment options are suitable, surgery appears to induce a faster resolution of edema and perhaps may alleviate edema-induced deficits faster in patients with brain metastases.