Supplementary Material for: A New Sarcoma Shortly After Treatment for High-Grade Glioma with Adjuvant Chemoradiation: A Case Report.

High-grade gliomas are central nervous tumors conventionally treated with surgery followed by adjuvant chemo-radiotherapy. Secondary cancer due to radiation therapy is a rare yet established phenomenon that typically occurs years after radiation therapy. In this case, we discuss an early presentation of a second cancer adjacent to the radiation field. This case report is of a 52-year-old male who developed a new sarcoma at the site of primary surgery eight months after radiation therapy. The report highlights that this case does not conform to the expected criteria for post-radiation sarcoma in terms of timing. Genetic testing revealed a heterozygous missense variant in the NF1 gene, a variant of uncertain significance. Secondary cancers may arise earlier than expected, even in phenotypically normal patients. The question of pre-radiotherapy screening for radiosensitivity syndromes and diseases requires further study.