Brain metastases in lung cancer patients: Correlation between radiologic phenotypes and outcome parameters in neurosurgically treated cohort

Background Up to 50% of Brain metastases (BM) are associated with lung cancer. Different radiologic features such as tumor size, anatomical location and peritumoral edema affect the clinical course. However, their impact on prognosis and survival is controversial. Patients and Methods A retrospective study of lung cancer patients who underwent surgical resection of solitary BM. Based on pre-operative radiologic features of the BM, the cohort was divided into 3 groups: solid, cystic-necrotic, and purely cystic lesion. Extent of peritumoral edema and the cerebral vascular territory affected were also examined. Results The studied cohort included 89 patients. Following categorization, 24 (27%), 46 (51.6%) and 19 (21.4%) cases were considered solid, cystic-necrotic and purely cystic, respectively. Severity of peritumoral edema ( p = 0.019) as well as the vascular territory affected ( p = 0.011) were the principal differences between groups. Rate of distal brain recurrence was nearly two-fold higher in the purely cystic subgroup vs. the cystic-necrotic subgroup ( p = 0.075). On multivariable analysis, adjusted to vascular territory and edema severity, only purely cystic lesions were significantly associated with increased risk for distal recurrence (HR = 2.92, p = 0.040) and showed a trend towards worse progression–free survival (HR = 2.10, p = 0.089) when compared to solid cases. Overall survival curves showed no significant difference between groups. Conclusion The radiologic phenotype of BM seems to have limited impact on OS in surgically treated lung cancer patients. Purely cystic BM might be associated with unfavorable risk for distal recurrence. For some outcome parameters, meaningful differences between the 3 radiologic groups were found, suggesting potential clinical implications.