BMET-27. PROGNOSTIC FACTORS IN TREATMENT OF CEREBRAL METASTASES

Abstract

BACKGROUND: Regardless of treatment advances, the prognosis of brain metastasis is dismal. Adequate drug delivery is counteracted by the blood-brain barrier. Surgical resection followed by radiotherapy (or SRS) remains the main option for these patients. We investigated radiological and clinical data to identify factors influencing overall survival (OS) in patients with cerebral metastases. Special emphasis was put on the extent of edema, which has been discussed as a marker of infiltration and thus aggressiveness of the tumor. METHODS: 143 patients with cerebral metastasis (m:f=1,1:1) who underwent surgical resection were retrospectively analyzed. The volume of tumor (Vmet) and edema (Ved) was calculated using Osirix. To facilitate statistical analysis, the cohort was dichotomized according to a coefficient calculated from the volumetric data of metastasis and edema (Ved / Vmet). Statistical analysis was performed to assess the influence of tumor and edema volume in addition to other clinical parameters on OS. RESULTS: The median Vmet amounted to 15,2cc (0,8-90,8) and the median Ved to 40,4cc (0-179,9). Divided in the different primaries, a significant correlation of the tumor volume to OS could be shown in lower GIT (p=0,02), melanoma (p=0,01) and lung cancer (p<0,001). 41 patients (28,6%) showed small edema (coefficient <1) and 102 patients 71,4%) presented with large edema (coefficient >1). Metastases within the cerebellum had significantly less edema (p<0,001). The factors associated with prolonged OS were extent of resection (biopsy/GTR p=0,001; biopsy/ STR p=0,04; STR/GTR n.s.), WBRT (p<0,001), female sex (p=0,029), RPAclass (RPA1/RPA2/RPA3 p=0,005, OR 2,212). There was no correlation between OS and the coefficient Ved / Vmet (p=0,381, OR=1,188(0,812- 1,739)). CONCLUSION: The outcome of cerebral metastases was influenced by extent of resection, postoperative radiotherapy and RPA-class. Nevertheless, in some subgroups of our cohort, there was a significant relationship between tumor volume and OS. A relationship of Ved with OS could not be detected.