Medulloblastomas: clinical profile, treatment techniques and outcome - an institutional experience.

ABSTRACT

The present series reports an audit on the patterns of presentation, radiation treatment techniques, failure pattern and outcome in the 36 patients treated at a single institution. Patients were accrued between October 1991 and September 1999. They underwent total or subtotal resection along with craniospinal irradiation. The dose to the cranium ranged from 30 to 43Gy (median- 36Gy), to the spine from 20 - 36Gy (median- 36Gy) and the posterior fossa boost, which was delivered in 32 cases, ranged from 14 to 24Gy (median -18Gy). Simulator film evaluation was carried out at the time of analysis based on the French Medulloblastoma Group guidelines, which revealed a significant under-dosage in the region of posterior fossa and cribriform plate in 27% and 19% respectively. Adjuvant chemotherapy was administered in 7 patients. Salvage treatment in the form of chemotherapy (5 cases) and re-irradiation (2 cases) were attempted but were ineffective. The overall survival (OS) and progression free survival (PFS) rates were 54% and 40% respectively, with the median being 75 and 29 months respectively. Amongst all the prognostic factors considered, on univariate analysis, duration of symptoms was significant for PFS with a trend towards significance for OS, while extent of debulking had a trend towards significance for PFS. No factor emerged significant on multivariate analysis.