Therapy-Related Long-Term Effects in Childhood Posterior Fossa Tumors

Background: Posterior fossa tumors constitute 60-70% of central nerve system tumors in children. These are localized in the cerebellum and the brain stem. The most common tumor types are medulloblastoma, astrocytoma and ependymoma. Treatment for these life-threatening neoplasms is established mainly according to the tumor type and can consist of surgery, radiotherapy and chemotherapy. Since survival rates have significantly increased during the last decades, long-term therapyrelated effects have become more and more important. This study aims to give an extensive review of all treatment-related long-term sequelae in posterior fossa tumor survivors. Method: The PubMed/Medline database was screened for articles published in 1990-2017 using the following search algorithm: ("Infratentorial Neoplasms"(Mesh) OR cerebellar tumor OR brain stem tumor) AND ("Child"(Mesh) OR "Infant"(Mesh) OR "Adolescent"(Mesh)) AND treatment AND (long term sequelae OR outcome). Studies including only adult patients or patients currently in treatment, studies not covering long-term effects and non-original research articles were excluded. Findings: The search algorithm returned 1367 articles. After a full screening procedure, 66 studies were retained for the qualitative analysis. The most frequent long-term sequelae were neurological complications, endocrine deficits, speech problems and intellectual impairment. Medulloblastoma patients suffered the greatest therapyrelated morbidity. Other important risk factors for worse long-term outcome were radiation dose, radiation volume, preoperative hydrocephalus and younger age at diagnosis. Conclusion: Therapy-related long-term effects are very frequent in all posterior fossa tumor survivors and comprise a broad spectrum of somatic, neuropsychological and psychosocial issues. Therefore, allcaregivers involved should be aware of these sequelae, to maximally support vulnerable children who survived their cancer.