Central Nervous System Metastasis in Neuroblastoma: From Three Decades Clinical Experience to New Considerations in the Immunotherapy Era

SIMPLE SUMMARY: Central nervous system (CNS) metastatic spread in neuroblastoma (NB) is rare and occurs more often at relapse/progression. In this retrospective study, we reviewed the CNS imaging of all the patients treated at the Bambino Gesù Children Hospital over a 25-year period. CNS metastasis in NB is confirmed to be rare, occurring in 4.7% of patients, and associated with advanced disease and bone skull involvement. In the last decade, the involvement of CNS at relapse has been observed more frequently, supporting the rising concern of the impact of immunotherapy in the pattern of relapse in high risk (HR) NB. Further studies are needed to confirm a higher CNS relapse risk in the immunotherapy era as well as the need for including CNS imaging in follow-up. ABSTRACT: Central nervous system (CNS) metastatic spread in neuroblastoma (NB) is rare and occurs more often at relapse/progression. We report on CNS involvement in high risk (HR) NB over 25 years. For this retrospective study, we reviewed the CNS imaging of all the patients treated at Bambino Gesù Children Hospital from 1 July 1996 to 30 June 2022. A total of 128 patients with HR NB were diagnosed over 26 years. Out of 128 patients, CNS metastatic spread occurred in 6 patients: 3 patients presented a metastatic spread at diagnosis, while in 3 patients, CNS was involved at relapse. Overall, the rate of occurrence of CNS spread is 4.7% with the same distribution at diagnosis and at relapse, namely 2.3%. Interestingly, CNS spread at diagnosis was observed only before 2012, whereas CNS was observed at relapse only after 2012, in the immunotherapy era. CNS metastases presented similar imaging features at diagnosis and at relapse, with a peculiar hemorrhagic aspect and mainly hemispheric localization in patients with bone skull involvement at the time of diagnosis. The outcome is dismal, and 3 out of 6 patients died for progressive disease.