Retreatment of recurrent adult medulloblastoma with radiotherapy: a case report and review of the literature

INTRODUCTION: Medulloblastoma, the most frequent brain tumor in childhood, also occurs with a wide range of characteristics in adult patients. Late relapse is common in adult medulloblastoma, and the overall survival of relapsed patients usually ranges from 12 to 15 months. Treatment at recurrence is still debated and after reoperation includes stereotactic or normofractionated radiotherapy, and high-dose chemotherapy with autologous bone marrow transplantation. CASE PRESENTATION: We report on the case of a 31-year-old Caucasian woman who underwent re-irradiation for a recurrence of medulloblastoma at nine years after first irradiation (56Gy), focusing on the radiobiological background and a review of previous studies involving re-irradiation of recurrent medulloblastoma. After surgical excision of the relapsed tumor and medical multi-agent treatment, the site of recurrence was treated using three-dimensional conformal radiotherapy to a total dose of 52.8Gy (1.2Gy/fraction/twice daily). A total biological equivalent dose of 224.6Gy (α:β = 2 Gy) was delivered to the posterior fossa (first and second treatments). No radionecrosis or local recurrence was evident at 18 months after re-irradiation. CONCLUSION: Re-irradiation can be considered a possible and safe treatment in selected cases of recurrent medulloblastoma in adults. The reported radiobiological considerations could be useful in other cases involving re-irradiation of brain tumors.