Proton beam therapy in a patient with secondary glioblastoma 32 years after postoperative radiotherapy for medulloblastoma: A case report and review of the literatures

Abstract In the past, for children's medulloblastoma tumors, the priority of cancer treatments was to control the tumor rather than the risk of side effects. With the gradual standardization of diagnostic and therapeutic techniques for children's medulloblastoma tumors, especially the application of stratified treatment guided by its molecular typing and multidisciplinary integrated treatment such as surgery, chemotherapy, radiotherapy, the cure, and survival of children's medulloblastoma tumor patients have been significantly improved. At the same time, there has been an increase in the number of second primary tumors (SPT). According to the concept of multiple primary tumors defined by the International Agency for Research on Cancer (IARC), two or more primary tumors are found in the patient simultaneously or successively. The tumor diagnosed first is known as the primary tumor, and the tumor diagnosed later is known as the SPT. The most frequent site of SPT is the CNS, followed by endocrine and hematological systems. However, there is less data on second primary glioblastoma and treatment modality recommendations after medulloblastoma. The purpose of this article is to share a case of a patient with medulloblastoma who developed a second primary glioblastoma 32 years after receiving craniospinal irradiation as a child. Additionally, it aims to provide insights into the treatment experience and present a review of relevant literature.