Therapeutic Considerations in Tumors Affecting The Central Nervous System: Ependymomas

Abstract

Ependymomas constitute a small but well defined group of the gliomas. The facts that all reported series are relatively small and that systems of classification differ probably account for the divergent opinions on therapy and prognosis. In Olivecrona's surgically treated patients, the five-year survival rate was 15 per cent for supratentorial ependymomas and 33 per cent for infratentorial ependymomas (15). Ley and his co-workers (9), as recently as 1962, expressed the opinion that radiation therapy is apparently of no value in these lesions. On the other hand, Bouchard and Peirce (3) reported five- and ten-year survival rates of 58 and 50 per cent respectively after postoperative irradiation. The present report includes all intracranial ependymomas treated at the University of California Medical Center 1930 to 1961, inclusive. Since ependymomas arising in the spinal cord present different therapeutic problems and a different prognosis, these lesions have been excluded. Materials and Methods The records of cases diagnosed as intracranial ependymoma during this period were reviewed. Histologic evidence was found in 42, including 3 with choroid plexus papillomas. (All histopathologic material was restudied by one of us, E. B.) The diagnosis was established by operation in 41, and by necropsy in 1 patient who died after ventriculography. To ensure that no intracranial ependymoma was overlooked, the records of all primary spinal ependymomas were also reviewed. None of these spinal tumors had evidence of intracranial origin or extension. Operative treatment consisted of the removal of as much tumor as was considered safe without significantly increasing the neurologic deficit. Obstruction of flow of the cerebrospinal fluid was relieved in most patients; a by-pass shunt was required in some instances. Eleven patients (26 per cent) died within two months after surgery.2 One death followed ventriculography, and 10 followed craniotomy and resection. The operative mortality since 1940 has been 19 per cent. These figures may be compared with those of Ringertz and Reymond (15). Of their 21 patients with supratentorial ependymoma, 3 died after ventriculography and 4 after surgery. In their 33 patients with infratentorial ependymomas, 18 died; 1 without operative procedure, 2 after ventriculography, and an additional 15 following surgery. Of our 31 patients who survived at least two months after operation, 28 received radiation therapy, 3 before and 25 after surgery. The records do not state why 3 patients received no irradiation. Therapy was applied through from 2 to 7 fields. The relatively large fields ranged in size from 8 × 10 em. to 10 × 15 cm., but in no case did the primary radiation therapy include more of the spine than the upper three cervical vertebrae. Apparatus for both medium and megavoltage radiation therapy were available during this period, and adequate treatment was possible with either. One patient was treated with a 70-Mev synchrotron.