Pattern of recurrence in children with midline posterior fossa malignant neoplasms

Background. Surveillance imaging of the brain and spinal neuraxis in patien ts with posterior fossa malignant tumors is commonly performed, with the as sumption that early detection of tumor recurrence will improve outcome. How ever, the benefit of this imaging has not been proven. Purpose. To evaluate the usefulness of spinal surveillance imaging in child ren with nonmetastatic (at diagnosis, M0) posterior fossa ependymoma and me dulloblastoma. Materials and methods. This retrospective study included 65 children (3 mon ths to 16 years, mean 5.7 years) treated between 1985 and 1997 for ependymo ma (22) and medulloblastoma (43). Medical records were reviewed for patholo gy and treatment data. Serial imaging of the head and spine was reviewed fo r evidence of tumor recurrence. Results. Twenty-four patients (37 %) had tumor recurrence, including 13 wit h ependymoma and 11 with medulloblastoma. Of the 17/24 recurrent patients i nitially diagnosed as M0 (6 medulloblastoma and 11 ependymoma), 13 (76 %) h ad a cranial recurrence only, and 4 (24 %) presented with concomitant crani al and spinal recurrence. No M0 patient presented solely with spinal metast ases at recurrence. Conclusion. This study suggests that spinal surveillance imaging in patient s with posterior fossa ependymoma or medulloblastoma initially staged as M0 may not be useful, as these patients initially recur intracranially. Thus, until an intracranial recurrence is detected, these patients may be spared the time, expense and sedation risk necessary for spinal imaging.