The impact of myelography on the treatment results for medulloblastoma.

Two series of newly diagnosed patients with medulloblastoma are compared in terms of survival, relapse-free survival, and sites of relapse. Patients in series I were all diagnosed and treated prior to 1974 and did not have the benefit of myelography and CSF cytology for staging. All patients treated after 1974 had myelography and most had CSF cytology studies prior to radiotherapy. In addition, patients in the latter series were all followed with CT scanning. Improved survival and relapse-free survival rates were seen in the series II patients. Approximately 30% of the staged patients have had abnormal myelograms. It is suggested that involved portions of the cord be treated with higher doses than the usual prophylactic doses. The better results seen in the series II patients are probably due in part to a combination of adequate staging with radiation doses to the neuraxis based on the staging, close followup with CT scanning, and aggressive re-treatment of relapses.