Proton Beam Therapy for a Rare Anaplastic Pleomorphic Xanthoastrocytoma: Case Report and Literature Review.

Anaplastic pleomorphic xanthoastrocytoma (PXA) is a rare, aggressive WHO grade III tumor that primarily affects children and young adults. Despite surgery being the primary treatment, achieving complete tumor removal is often difficult due to its infiltrative nature, necessitating additional therapies like proton beam therapy (PBT). PBT, known for its precision in targeting tumors while minimizing damage to surrounding healthy tissue, has shown promise in treating malignant gliomas. We present the case of a 9-year-old girl with anaplastic PXA treated with PBT following incomplete surgical resection. A total dose of 60 Gy (RBE) in 15 fractions was administered, leading to significant tumor reduction, no progression, and improved local control at the 1-year follow-up, with no observed adverse effects. Based on short-term follow-up results, our study highlights the potential of PBT in managing anaplastic PXA, demonstrating favorable local outcomes and a low incidence of radiation-induced complications. While long-term follow-up and evaluation are necessary to further support these findings, this case represents only the second reported instance of anaplastic PXA treated with PBT, contributing to the growing body of evidence supporting its efficacy in this rare tumor type.