Adult medulloblastoma following fractionated proton therapy for acoustic neuroma

Abstract

Introduction: Radiation-induced medulloblastoma is exceedingly rare. Four cases of adult medulloblastoma were previously reported to have occurred following whole brain or craniospinal irradiation. Development of systemic malignancies secondary to proton beam therapy is extremely uncommon, with a lifetime risk lower than 1 %. Methods and Results: A 39-year-old woman presented with gait instability and a right cerebellar mass following an 8-year latency period post-fractionated proton therapy for an acoustic neuroma. To date, no cases of new onset medulloblastoma have been reported following proton beam therapy. The differential diagnosis by imaging studies includes brain radiation necrosis. Conclusion: The current report highlights the possible, although rare, risks and complications associated with proton beam radiation. Further studies are needed to address issues related to the management and treatment of radiationinduced medulloblastomas.