Pediatric posterior fossa tumor
Approximately half of pediatric central nervous system tumors are located in the posterior fossa.
Pilocytic astrocytomas (PAs), medulloblastomas (MBs), and ependymomas are the most common posterior fossa tumors.
High grade gliomas, atypical teratoid/rhabdoid tumor, and choroid plexus papilloma of the fourth ventricle are less frequent.
Because of the different treatment options and variability in long-term outcome, an accurate and specific diagnosis is mandatory 1).
A developmental and anatomic approach to the posterior fossa tumors in children (together with diffusion imaging data) provides a reliable pre-surgical identification of the tumor and of its aggressiveness 2).
Over the last decades, the mortality rate of children with posterior fossa tumors has gradually decreased. While survival has been the primary objective in most reports, quality of survival increasingly appears to be an important indicator of a successful outcome. Children with a PF tumor can sustain damage to the cerebellum and other brain structures from the tumor itself, concomitant hydrocephalus, the consequences of treatment (surgery, chemotherapy, radiotherapy), or a combination of these factors. Together, these contribute to long-term sequelae in physical functioning, neuropsychological late outcomes (including academic outcome, working memory, perception and estimation of time, and selective attention, long-term neuromotor speech deficits, and executive functioning). Long-term quality of life can also be affected by endocrinological complication or the occurrence of secondary tumors. A significant proportion of survivors of PF tumors require long-term special education services and have reduced rates of high school graduation and employment. Interventions to improve neuropsychological functioning in childhood PF tumor survivors include (1) pharmacological interventions (such as methylphenidate, modafinil, or donepezil), (2) cognitive remediation, and (3) home-based computerized cognitive training. In order to achieve the best possible outcome for survivors, and ultimately minimize long-term complications, new interventions must be developed to prevent and ameliorate the neuro-toxic effects experienced by these children 3).
Age at diagnosis and treatment factors are important variables that affect the outcomes of the survivors 4).