Pattern of recurrence in children with midline posterior fossa malignant neoplasms

Surveillance imaging of the brain and spinal neuraxis in patients with posterior fossa malignant tumors is commonly performed, with the assumption that early detection of tumor recurrence will improve outcome. However, the benefit of this imaging has not been proven.

To evaluate the usefulness of spinal surveillance imaging in children with nonmetastatic (at diagnosis, M0) posterior fossa ependymoma and medulloblastoma.

This retrospective study included 65 children (3 months to 16 years, mean 5.7 years) treated between 1985 and 1997 for ependymoma (22) and medulloblastoma (43). Medical records were reviewed for pathology and treatment data. Serial imaging of the head and spine was reviewed for evidence of tumor recurrence.

Twenty-four patients (37 %) had tumor recurrence, including 13 with ependymoma and 11 with medulloblastoma. Of the 17/24 recurrent patients initially diagnosed as M0 (6 medulloblastoma and 11 ependymoma), 13 (76 %) had a cranial recurrence only, and 4 (24 %) presented with concomitant cranial and spinal recurrence. No M0 patient presented solely with spinal metastases at recurrence.

This study suggests that spinal surveillance imaging in patients 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.