Treatment Strategies for Recurrent Olfactory Neuroblastoma

Introduction: Olfactory neuroblastoma (ONB) is a rare skull base malignancy. Primary treatment is typically surgical resection via an endoscopic endonasal approach which may be combined with an open approach for more advanced tumors. Recurrent disease is not uncommon, occurring in 30 to 50% of cases. Median time to recurrence is characteristically late at about 5 years. Detailed management of recurrences stratified as local to or distant from the primary tumor has not been previously reported. The present study summarizes the treatment of recurrent olfactory neuroblastoma from one institution.

Methods: A single-institution retrospective review study design was used. Patients presenting with recurrent ONB from April 2006 to February 2021 were included. Demographics and disease-specific history were reviewed. Treatment history is described. Descriptive statistics were used.

Results: A total of 27 cases were identified. The mean time to recurrence was 59 months. Location of recurrence was local (sinonasal/orbital) in 13 cases (48%), local intracranial in 11 cases (41%), distant intracranial in 9 cases (33%), regional in 13 cases (48%), and distant extracranial in three cases (11%). 16 cases underwent surgery for local sinonasal or local intracranial disease, two underwent surgery for distant intracranial disease, 12 underwent surgery for regional disease, 14 patients underwent irradiation, two patients underwent chemotherapy or immunotherapy, and 7 patients underwent radioligand therapy. 5 patients (20%) had no evidence of disease one year following salvage treatment and 4 patients (16%) had no evidence of disease five years following salvage treatment. 7 patients (28%) had at least one additional recurrence and 12 patients (48%) had persistent disease. Additional recurrences occurred a mean of 39 months after treatment of prior recurrences.

Conclusion: Surgery, radiation and radioligand therapy were the most common salvage treatments used for recurrent olfactory neuroblastoma. Persistent disease and additional delayed recurrences were not uncommon. Distant intracranial disease was addressed surgically in two cases; however, it was more frequently managed with radiation and radioligand therapy. Several patients treated with radioligand therapy for distal intracranial or refractory regional disease were noted to have stable disease for over one year.