Timing of radiation in children with medulloblastoma/PNET.

BACKGROUND

To evaluate the importance of timing of radiation therapy in children with PNET/medulloblastoma, treated at the Brazilian National Cancer Institute (INCA).

PROCEDURE

The records of 101 children with confirmed diagnosis of medulloblastoma were retrospectively reviewed. Patients had a median follow-up of 48 months (0.5-241 months). The age varied from 0.8 to 17.5 years (median: 7.6 years) and 21.7% were 3 years old or younger.

RESULTS

According to the data collected from patients that received treatment for medulloblastoma from 1983 to 2001, the overall survival (OS) rate was 53% and the Disease Free Survival (DFS) rate was 40%. Multivariate analysis showed that under age 3 years, presence of neoplasic cells in the cerebrospinal fluid (CSF) at presentation or subtotal tumor resection resulted in a worse OS. The patients that received a biological effective dose (BED) greater than 44 Gy10 had better prognosis. Two-thirds of the patients had complete response after the initial treatment. Among them, 50% (34 patients) recurred, and of those 34 patients, 42% of them (14 patients) had recurrence in the posterior fossa.

CONCLUSION

Surgery with total resection of the tumor and absence of neoplasic cells in the CSF are effective predictors of better OS. Radiotherapy was more effective when a BED was greater than 44 Gy10.