Outcome and Predictive Factors of Radiation Therapy for Medulloblastoma: Mansoura Experience

Background: Medulloblastomas are the most common infratentorial malignant brain tumors with an incidence rate of 0.5 in 100.000 typically arising in childhood at age 5-9 years.

Aim of Work: Exploring the epidemiological characteristics, treatment outcome and prognostic factors of medulloblastoma patients whom were referred to Mansoura Clinical Oncology &Nuclear Medicine Department for adjuvant treatment through the period from Jan. 1997 to Dec. 2011 inclusive.

Patients and Methods: Sixty-Two patients records were in harmony with the eligibility criteria . Males were slightly larger in number [33 cases (53%)]. The majority of the cases were of pediatric age (42 patient representing 68%). Complete resection was possible in only 31 cases (50%).The classic type was the commonest [36 cases (58%)]. The majority were of the of M0 stage [52 cases (84%)] and of high risk category [37 cases (60%)]. Median dose to posterior fossa was 52.5 Gray (range, 43-56 Gray). The Chemotherapy was administrated in forty-seven patients (75.8%). The toxicity of treatment were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 3.0).

Results: Adjuvant Radiotherapy was generally well tolerated. The median overall survival time and median progression – free survival were 90 & 72 months respectively. Relapse was reported in 28 patients (45.16%).M staging, extensiveness of resection, hydrocephalus at presentation and time elapsed till radiotherapy all affected significantly the prognosis.

Conclusion: In conclusion, this study highlights the effect of stage, completeness of surgery, and early initiation of adjuvant radiotherapy on the outcome.