The biology of childhood ependymomas.

The biology of 74 childhood ependymomas has been retrospectively investigated in total population samples from three hospitals in two cities. Regardless of the tumor's site of origin, the prognosis is grim. No child has been cured by surgery alone. The symptom-free interval after surgery is a first-order function of the age at diagnosis. The criteria for cure are best approximated by Collins "law," in terms of which there are apparently only three cured patients in this study. Intracranial ependymomas are best treated by careful excision of the tumor and radiation of a generous area to a total dose of at least 4,500 rads over a 60-day period. Radiation of the entire neuraxis appears to be indicated only in those few cases that can be considered malignant microscopically.