An audit of craniospinal irradiation for medulloblastoma in Newcastle 1970-1992.

The case notes were reviewed of 55 patients treated with craniospinal irradiation for cerebellar medulloblastoma during the period 1970-1992. Twenty patients treated by various techniques before 1978 had a survival at both 5 and 10 years of 33%. Thirty-five patients treated from 1978 onwards were irradiated using a standard technique, which is described; their actuarial disease free survival was 59% at 5 years and 47% at 10 years. Our results are similar to those reported from other centres. The recent literature is reviewed. Irradiation of the whole craniospinal axis (CSA) is necessary for disease control, but the optimum dose of radiation is still disputed. It is likely to be in excess of 25 Gy but less than 35 Gy to the whole CSA, and 50 Gy or greater to the posterior fossa. The role of adjuvant chemotherapy is still not proven. The clinical significance of the dose inhomogeneity across the junction between the cranial and spinal fields, and the effect of feathering, are uncertain.