Induction Chemotherapy for Sinonasal Tumors in Patients Presenting with Brain Invasion and/or Neurological Deficits.

 The aim of this study was to investigate the safety of induction chemotherapy (IC) for patients with sinonasal malignancies with brain invasion or a neurological deficit.  We conducted a retrospective analysis of patients who underwent IC for sinonasal malignancies with intracranial invasion or a neurological deficit at a single tertiary cancer center from 1992 to 2020.  In total, 460 patients with sinonasal malignancies were included in the study. Of the patients reviewed, 341 underwent IC and within this group 40 had brain invasion (BI) and 31 had a neurological deficit (ND) at presentation. The most prevalent malignancy was sinonasal undifferentiated carcinoma (BI 40%, ND 41.9%), followed by esthesioneuroblastoma (BI 27.5%, ND 9.7%). All tumors were stage T4 with the majority lacking nodal metastases (BI N0: 72.5%, ND N0: 77.5%). All patients completed at least two cycles of IC. Partial or complete response to IC was seen in 80% of BI and 71% of ND patients. No patients had cessation of treatment due to neurologic decline and none required urgent surgery. Five patients (12.5%) with BI and 2 (6.5%) with ND had interruption of IC for reasons other than neurological decline. In patients with ND, IC led to improvement of 54.5% NDs.  In patients with sinonasal malignancies with BI or ND who underwent IC, no patients had cessation of treatment due to neurologic decline. In contrast, most patients had improvement of neurologic symptoms with IC. IC was safely administered without interruption due to neurological decline or symptom progression.